CN118358393A

CN118358393A - Three-phase electric automobile energy interaction control system and control method thereof

Info

Publication number: CN118358393A
Application number: CN202311740486.8A
Authority: CN
Inventors: 王燕彬; 蒋劲松; 刘文华; 李明冬; 徐磊; 李明
Original assignee: Weilai Automobile Technology Anhui Co Ltd
Current assignee: Weilai Automobile Technology Anhui Co Ltd
Priority date: 2023-12-15
Filing date: 2023-12-15
Publication date: 2024-07-19

Abstract

The application provides a three-phase electric automobile energy interaction control system and a control method thereof, wherein the control method comprises the following steps: the energy conversion module is used for converting an input three-phase alternating current power supply into direct current electric energy suitable for charging an electric automobile and carrying out power factor correction; the energy control module is connected with the energy conversion module and is used for receiving the direct-current electric energy output by the energy conversion module and realizing the charge and discharge operation of the battery of the electric automobile so as to realize the bidirectional conversion of the electric energy; the monitoring module is respectively connected to the energy conversion module and the energy control module and is used for monitoring the working states of the energy conversion module and the energy control module so as to output real-time monitoring data; the interaction module is respectively connected to the energy control module and the monitoring module and is used for receiving the real-time monitoring data and displaying the real-time monitoring data to a user; and when the energy control module needs to feed back energy to the power grid, the interaction between the electric automobile and the power grid is realized through the interaction module. The application can realize the V2G mode of the electric automobile.

Description

Three-phase electric automobile energy interaction control system and control method thereof

Technical Field

The application relates to the technical field of electric automobiles, in particular to an energy interaction control system and a control method of a three-phase electric automobile.

Background

With the popularization of electric vehicles, the energy storage capacity of a power battery is also increasing, and the V2G (Vehicle-to-grid) technology is used as a key technology, so that the electric vehicles are allowed to interact with a power grid, and the energy stored by the power battery is purchased and charged from the power grid when the electricity price is low, and sold to the power grid when the electricity price is high, so that the bidirectional energy transmission of the power battery can be realized, and meanwhile, economic benefits are brought to users of the electric vehicles.

However, the conventional electric vehicle dc charging pile generally only performs charging operation, and cannot realize energy feedback from the electric vehicle to the power grid (i.e., cannot support the V2G mode). In addition, these charging piles generally support only the charging of the power battery of the 400V voltage platform, and cannot be compatible with both the charging and discharging operations of the electric vehicle under both the 400V and 800V voltage platforms.

Disclosure of Invention

The application provides a three-phase electric automobile energy interaction control system and a control method thereof, which are used for solving the problem of how to enable an electric automobile to realize a V2G mode.

In a first aspect, the present application provides a three-phase electric vehicle energy interaction control system, the system comprising:

the energy conversion module is used for converting an input three-phase alternating current power supply into direct current electric energy suitable for charging an electric automobile and carrying out power factor correction;

the energy control module is connected with the energy conversion module and is used for receiving the direct-current electric energy output by the energy conversion module and realizing the charge and discharge operation of the battery of the electric automobile so as to realize the bidirectional conversion of the electric energy;

The monitoring module is respectively connected to the energy conversion module and the energy control module and is used for monitoring the working states of the energy conversion module and the energy control module so as to output real-time monitoring data;

the interaction module is respectively connected to the energy control module and the monitoring module and is used for receiving the real-time monitoring data and displaying the real-time monitoring data to a user; and when the energy control module needs to feed back energy to the power grid, the interaction between the electric automobile and the power grid is realized through the interaction module.

In one embodiment of the present application, the monitoring module includes:

the control unit is used for controlling and adjusting the voltage, current and power parameters of the system in the charging and discharging process;

the voltage sampling unit is used for monitoring voltage signals of the energy conversion module and the energy control module to convert the voltage signals into digital signals for the control unit to use;

And the current sampling unit is used for monitoring current signals of the energy conversion module and the energy control module to convert the current signals into digital signals for the control unit to use.

In an embodiment of the application, the energy control module includes a bus-side full-bridge circuit, a resonant capacitor, a resonant inductance, a transformer network, a battery-side full-bridge network, and a first series-parallel relay and/or a second series-parallel relay, wherein the transformer network includes a first transformer and a second transformer, and the battery-side full-bridge network includes a first full-bridge network and a second full-bridge network.

In an embodiment of the present application, when the system works in the first mode, a control unit sends low-level driving signals to the first serial-parallel relay and the second serial-parallel relay respectively, so that the first serial-parallel relay and the second serial-parallel relay are continuously disconnected, further, a primary side winding of the first transformer and a primary side winding of the second transformer are connected in series, a secondary side winding of the first transformer is connected to the first full-bridge network and a secondary side winding of the second transformer is connected to the second full-bridge network, and current is output to the electric vehicle battery in parallel after passing through the first full-bridge network and the second full-bridge network respectively, so as to meet a charge and discharge requirement of the electric vehicle battery working at a first preset voltage.

In an embodiment of the present application, when the system works in the second mode, a control unit sends a high-level driving signal to the first serial-parallel relay and sends a low-level driving signal to the second serial-parallel relay, so that the first serial-parallel relay is continuously closed and the second serial-parallel relay is continuously opened, a primary winding of the first transformer and a primary winding of the second transformer are connected in series, the first serial-parallel relay is controlled to be continuously in a closed state, so that a secondary winding of the first transformer and a secondary winding of the second transformer are connected in series and then connected to the battery-side full-bridge network, and the battery-side full-bridge network is connected with the electric vehicle battery to meet a charge and discharge requirement of the electric vehicle battery working at a second preset voltage, wherein the second preset voltage is higher than the first preset voltage.

In an embodiment of the present application, when the system works in the second mode, a control unit sends a low-level driving signal to the first serial-parallel relay and sends a high-level driving signal to the second serial-parallel relay, so that the first serial-parallel relay is continuously opened and the second serial-parallel relay is continuously closed, and the second serial-parallel relay is controlled to be continuously in a closed state, so that a primary winding of the first transformer and a primary winding of the second transformer are connected in series, and a secondary winding of the first transformer and a secondary winding of the second transformer are connected in series and then connected to the battery-side full-bridge network, and the battery-side full-bridge network is connected with the electric vehicle battery, so as to meet the charging and discharging requirements of the electric vehicle battery working at a second preset voltage.

In one embodiment of the present application, the system further comprises:

The power supply filtering module comprises a three-phase alternating current filtering unit and a direct current filtering unit, wherein the three-phase alternating current filtering unit is used for filtering high-frequency switching noise generated by the energy conversion module so as to prevent the noise from being transmitted to a power grid side; the input end of the direct current filtering unit is connected with the output end of the energy control module, the output end of the direct current filtering unit is connected with the battery of the electric automobile, and the direct current filtering unit is used for filtering high-frequency switching noise generated by the energy control module so as to avoid noise from being transmitted to the battery side.

In one embodiment of the present application, the system further comprises:

And the input end of the three-phase alternating current pre-charging module is connected with the output end of the three-phase alternating current filtering unit, and the output end of the three-phase alternating current pre-charging module is connected with the input end of the energy conversion module and is used for controlling the output of the three-phase alternating current pre-charging module to realize the pre-charging of the energy conversion module through the control unit when the power supply system is started.

In one embodiment of the present application, the system further comprises:

and the input end of the switch driving module is connected with the control unit, and the output end of the switch driving module is respectively connected with the energy conversion module, the energy control module and the direct current filtering unit and is used for controlling the switch and the execution action of each module.

In an embodiment of the present application, the interaction module includes a communication unit, a display unit, and an interface unit, where the communication unit is used to establish communication connection with the remote control module; the display unit is used for displaying the charge and discharge states of the electric automobile; and the interface unit is in communication connection with the electric automobile.

In one embodiment of the application, the energy conversion module is a bidirectional ACDC circuit and the energy control module is a bidirectional DCDC circuit.

In a second aspect, the present application further provides a three-phase electric vehicle energy interaction control method, where the method is applied to the three-phase electric vehicle energy interaction control system according to any one of the first aspect, and the method includes:

In a charging mode, the control unit adopts a control strategy of double closed loops of direct current bus voltage and alternating current for the energy conversion module; the control unit adopts a double-loop competition control strategy of a voltage closed loop and a current closed loop for the energy control module;

In a grid-connected inversion mode, the control unit adopts an integrated control strategy of active power control, reactive power control, fault ride through control, anti-islanding control and PFC bus voltage regulation control for the energy conversion module; and the control unit adopts a double-loop competition control strategy of a voltage closed loop and a current closed loop for the energy control module.

In an embodiment of the present application, in a charging mode, the step of the control unit adopting a control strategy of dual closed loops of dc bus voltage and ac current for the energy conversion module includes:

Collecting a direct current bus voltage through a voltage sampling unit, and comparing the direct current bus voltage with a given reference voltage to output a voltage error signal, wherein the voltage error signal is then input into a voltage loop regulator for closed-loop control of a voltage loop;

Multiplying the result calculated and output by the voltage loop regulator by an alternating input voltage sampling signal of the energy conversion module to obtain alternating reference current;

Collecting inductance current through a current sampling unit, and comparing the inductance current with the alternating reference current to output a current error;

Calculating the current error by using a closed-loop control algorithm to generate a PWM duty cycle of the energy conversion module;

And regulating the PWM modulator according to the PWM duty ratio, and controlling the state of a switching tube of the energy conversion module so as to realize the control of alternating current input current and direct current bus output voltage.

In an embodiment of the present application, in a charging mode or a grid-connected inversion mode, the step of the control unit adopting a voltage closed loop and current closed loop double loop competition control strategy for the energy control module includes:

in steady state operation, only one loop works, and the other loop is in a saturated output state;

respectively performing voltage closed loop calculation and current closed loop calculation to obtain respective control results;

comparing the calculation results of the voltage closed loop and the current closed loop, and selecting a smaller calculation result as an output result of the loop;

And adjusting the frequency of the PWM signal of the energy control module according to the output result.

In an embodiment of the present application, in a grid-connected inversion mode, the steps of the control unit adopting a comprehensive control strategy of active power control, reactive power control, fault ride through control, anti-islanding control and PFC bus voltage regulation control for the energy conversion module include:

Setting target active power and reactive power;

active power control and reactive power control are carried out to meet the power requirement in a grid-connected inversion mode;

Performing fault ride-through control, and processing according to the low voltage ride-through and high voltage ride-through requirements of the power grid so as to ensure the fault ride-through function of the system under different power grid standards;

anti-islanding control is implemented, the connection state of a power grid is monitored, and the grid-connected inversion working mode is stopped when the system is separated from the power grid, so that the electric automobile is prevented from entering the islanding state;

And performing PFC bus voltage regulation control, and regulating the voltage of the PFC bus according to the change of the battery voltage of the electric automobile so as to optimize the charge/discharge efficiency of the system.

The application provides an energy interaction control system of a three-phase electric automobile and a control method thereof. This ensures the efficiency of the energy conversion and the ability to accommodate different power sources. The energy control module of the system is connected with the energy conversion module and is responsible for receiving direct-current electric energy from the energy conversion module and realizing charging and discharging operation of the battery of the electric automobile so as to realize bidirectional conversion of the electric energy. This allows the electric vehicle to flexibly charge or feed back energy from or to the grid. The monitoring module of the system is respectively connected to the energy conversion module and the energy control module and is used for monitoring the working states of the energy conversion module and the energy control module and outputting real-time monitoring data. This provides real-time feedback on the energy interaction process of the electric vehicle by monitoring the operating conditions of the system. The interaction module of the system is respectively connected to the energy control module and the monitoring module and is used for receiving real-time monitoring data and displaying the real-time monitoring data to a user. In addition, when the energy control module needs to feed back energy to the power grid, the interaction module can realize interaction between the electric automobile and the power grid. This provides a convenient user interface and the ability to track energy interactions.

Through the design, the application can realize the V2G mode of the electric automobile and support the bidirectional conversion of direct current electric energy. The technical effects include:

Realize the two-way energy conversion of electric automobile: the system allows the electric automobile to receive the electric energy and simultaneously feed the redundant electric energy back to the power grid, so that the electric automobile participates in energy allocation and storage of the power grid.

Providing real-time monitoring and user interaction functions: the monitoring module and the interaction module enable a user to monitor the running state of the system in real time and interact with the system through the interaction module so as to achieve better control and use experience.

Drawings

In order to more clearly illustrate the application or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the application, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1A is a flow chart of the three-phase electric vehicle energy interaction control system provided by the application;

FIG. 1B is a schematic diagram of an implementation of the V2G mode provided by the present application;

fig. 2 is a circuit diagram of an electric vehicle energy interaction control according to an embodiment of the present application;

Fig. 3 is a circuit diagram of energy interaction control of an electric vehicle according to a second embodiment of the present application;

FIG. 4 is a schematic diagram of energy flow in a charging mode provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of energy flow in grid-tie inversion mode provided by an embodiment of the present application;

FIG. 6A is an equivalent circuit diagram of an energy control module according to an embodiment of the present application operating in a low voltage charging or V2G mode;

FIG. 6B is a timing diagram of the switching signals of Q1-Q12 in the low voltage mode of charge and discharge in FIG. 6A;

FIG. 7A is an equivalent circuit diagram of an energy control module according to an embodiment of the present application operating in a high voltage mode;

FIG. 7B is a timing diagram of the switching signals of Q1-Q4, Q7, Q8, Q9, Q10 in the high voltage mode charge-discharge in FIG. 7A;

FIG. 8A is an equivalent circuit diagram of an energy control module according to an embodiment of the present application operating in a high voltage mode;

FIG. 8B is a timing diagram of the switching signals of Q1-Q12 in the high voltage mode of FIG. 7A;

FIG. 9A is a circuit diagram of an energy control module provided by another embodiment of the present application;

FIG. 9B is a circuit diagram of an energy control module provided by yet another embodiment of the present application;

FIG. 10 is a flow chart of the three-phase electric vehicle energy interaction control method provided by the application;

fig. 11 is a schematic diagram of a control strategy in a grid-connected inversion mode according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The terms first, second and the like in the description and in the claims and in the above-described figures, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments described herein may be implemented in other sequences than those illustrated or otherwise described herein.

Technical terms related to the present application are described as follows:

V2G is an abbreviation for "Vehicle-to-Grid" and refers to a process of bi-directional power interaction between an Electric Vehicle (EV) or a plug-in hybrid Vehicle (PHEV) and a Grid. The electric automobile can acquire electric energy from a power grid for charging. V2G technology allows electric vehicles to output electrical energy from a battery back to the grid for grid regulation, storage, or energy feedback. Thus, the electric vehicle can not only be a consumer, but also be a provider of energy resources. Through V2G technology, the electric automobile is not only a transportation means, but also can become a part of a smart grid and a renewable energy system, and contributes to the sustainability and stability of the energy system.

In order to solve the problem of how to enable an electric automobile to realize a V2G mode (also called a grid-connected inversion mode) in the prior art, the application provides an energy interaction control system of a three-phase electric automobile and a control method thereof. The energy control module of the system is connected with the energy conversion module and is responsible for receiving direct-current electric energy and realizing charge and discharge operation of the battery of the electric automobile so as to realize bidirectional conversion of the electric energy. The monitoring module of the system is connected to the energy conversion module and the energy control module and is used for monitoring the working states of the energy conversion module and the energy control module in real time and outputting monitoring data. The interaction module of the system is connected to the energy control module and the monitoring module, receives real-time monitoring data and provides a user interface for user interaction.

Therefore, the application can realize the V2G mode and the bidirectional energy conversion of the electric automobile, so that the electric automobile can charge from the power grid and feed back energy to the power grid. And providing real-time monitoring and user interaction functions, so that a user can know the running condition of the system in real time and interact with the system. That is, the application realizes the V2G mode and has the characteristics of bidirectional energy conversion, voltage platform adaptability and user friendliness.

The following describes a three-phase electric vehicle energy interaction control system and a control method thereof with reference to fig. 1A to 11.

Referring to fig. 1A and 1B, fig. 1A is a flowchart of an energy interaction control system for a three-phase electric vehicle provided by the present application, and fig. 1B is a schematic diagram for implementing a V2G mode provided by the present application. The three-phase electric vehicle energy interaction control system 100 comprises an energy conversion module 101, an energy control module 102, a monitoring module 103 and an interaction module 104.

The energy interaction control system of the three-phase electric automobile can be called as a three-phase direct current pile. Since a three-phase electric vehicle uses three-phase alternating current as a power source. Therefore, the three-phase electric vehicle energy interaction control system adopts a three-phase connection mode, and performs energy conversion and interaction through the energy conversion module 101. The three-phase electric automobile energy interaction system has three phases, and can process more power and energy simultaneously. Compared with a single-phase electric automobile energy interaction system, the three-phase electric automobile energy interaction control system has higher power output capability.

When the three-phase direct current pile receives a charging instruction from the remote control module and establishes connection and communication with the electric automobile, the direct current pile is controlled by a circuit in the direct current pile, so that the direct current pile works in a charging mode, alternating current of a power grid is converted into high-voltage direct current, and then the high-voltage direct current is transmitted to the battery of the electric automobile for charging. In addition, when the direct current pile receives a V2G discharging instruction from the remote control module and establishes connection and communication with the electric automobile, the direct current pile works in a V2G discharging mode through circuit control in the direct current pile, energy is taken out from a battery of the electric automobile and fed back to a power grid, meanwhile, the dispatching of the power grid is supported, and the requirements of the power grid on reactive support, fault ride-through and the like are met.

The energy conversion module 101 is used for converting an input three-phase alternating current power supply into direct current power suitable for charging an electric vehicle, and performing power factor correction, for example.

That is, the energy conversion module 101 functions to convert the input three-phase ac power into dc power suitable for charging an electric vehicle, and perform power factor correction.

Specifically, when the electric vehicle needs to be charged, the energy conversion module 101 receives ac power from an ac power source (e.g., a socket) provided from the outside. Then, it converts the ac power into dc power suitable for charging the battery of the electric vehicle.

In addition, the energy conversion module 101 also performs power factor correction. The power factor is a parameter in the circuit that describes the relationship between the actual power and the apparent power. By performing power factor correction, the energy conversion module may increase the efficiency of the energy conversion process, reduce energy losses, and follow grid requirements.

Therefore, the power factor correction of the energy conversion module 101 can improve the efficiency of electric energy conversion and reduce the energy loss. Moreover, the energy conversion module 101 can adapt to the input of different alternating current power sources and convert the input into direct current electric energy suitable for charging the electric automobile, so that the compatibility of the system is improved. Moreover, the energy conversion module 101 can ensure the stability and safety of the charging process of the electric vehicle through the conversion of the ac power supply and the correction of the power factor. The energy conversion module 101 plays a key role in the three-phase electric automobile energy interaction control system, and can efficiently and safely convert an alternating current power supply into direct current power so as to meet the charging requirement of the electric automobile.

The energy control module 102 is connected to the energy conversion module 101, and is configured to receive the dc power output by the energy conversion module 101, and perform charging and discharging operations on the battery of the electric vehicle to perform bidirectional conversion of the power.

That is, the energy control module 102 is connected to the energy conversion module 101, and is configured to receive the dc electrical energy output by the energy conversion module 101, and implement charge and discharge operations on the battery of the electric vehicle, thereby implementing bidirectional conversion of the electrical energy.

Specifically, after the energy conversion module 101 converts the ac power into the dc power suitable for charging the electric vehicle, the energy control module 102 receives the dc power. Then, the energy control module 102 can transmit the direct current electric energy to the battery of the electric automobile for charging according to the requirement, and can release the energy from the battery according to the requirement, so as to realize the discharging operation of the battery of the electric automobile.

Through such bi-directional charge and discharge operations, the energy control module 102 achieves bi-directional conversion of electrical energy. When the electric vehicle needs to be charged, the energy control module 102 obtains and stores electric energy from the energy conversion module 101 into a battery. When the electric vehicle needs to release energy or feed back energy to the power grid, the energy control module 102 can control the battery to release energy, so as to feed back electric energy to the power grid.

Therefore, the energy control module 102 can regulate the charging and discharging process of the battery of the electric vehicle, so as to realize that the electric energy is transmitted from the power grid to the electric vehicle for storage and charging, and the energy in the battery of the electric vehicle is released for feedback to the power grid. Also, the presence of the energy control module 102 enables the electric vehicle to perform charging and discharging operations as desired, providing flexibility and controllability of the energy conversion process. The energy control module 102 is used for managing the energy state of the battery of the electric automobile, and communicates with an external system to realize the functions of energy interaction and energy management. Through the energy control module 102, the electric automobile can realize bidirectional energy conversion in the process of charging and discharging the battery, and flexible utilization and efficient management of electric energy are realized.

Illustratively, the monitoring module 103 is respectively connected to the energy conversion module 101 and the energy control module 102 for monitoring the operating states of the energy conversion module 101 and the energy control module 102 to output real-time monitoring data.

That is, the monitoring module 103 is connected to the energy conversion module 101 and the energy control module 102, respectively, for monitoring their operating states and outputting real-time monitoring data.

Specifically, the monitoring module 103 may be connected to the energy conversion module 101 and the energy control module 102 to receive their operating status information. By monitoring the operating states of the energy conversion module 101 and the energy control module 102, the monitoring module 103 can detect the operation and performance of the two modules in real time.

The monitoring module 103 also outputs the monitored real-time data so that a user or other system can acquire and analyze the data. These real-time monitoring data may include parameters related to power conversion efficiency, temperature, current, etc. of the energy conversion module 101 and the energy control module 102.

Thus, the monitoring module 103 may continuously monitor the operating states of the energy conversion module 101 and the energy control module 102 as needed and provide real-time updated data. In addition, by the real-time monitoring data provided by the monitoring module 103, faults or abnormal conditions of the energy conversion module 101 and the energy control module 102 can be timely found and diagnosed. Moreover, the real-time monitoring data can be used to evaluate the performance of the energy conversion module 101 and the energy control module 102 and provide optimization suggestions to improve the efficiency and reliability of the system. The monitoring module 103 can obtain the working states and performance parameters of the energy conversion module 101 and the energy control module 102 in real time, and provides important data support for the operation, maintenance and optimization of the system.

Illustratively, the interaction module 104 is respectively connected to the energy control module 102 and the monitoring module 103 for receiving real-time monitoring data and displaying to a user; when the energy control module 102 needs to feed back energy to the power grid, interaction between the electric automobile and the power grid is achieved through the interaction module 104.

That is, the interaction module 104 is connected to the energy control module 102 and the monitoring module 103, respectively, for receiving real-time monitoring data and displaying to a user. Meanwhile, when the energy control module 102 needs to feed back energy to the power grid, the interaction module 104 can realize interaction between the electric automobile and the power grid.

Specifically, the interaction module 104 may be connected to the energy control module 102 and the monitoring module 103 to receive real-time monitoring data. The data includes information such as the operating state of the system, operating parameters, etc. The interactive module 104 processes and displays these real-time monitoring data to the user, providing them with the ability to learn about the system conditions in real-time.

In addition, the interaction module 104 also plays a role in interaction between the electric vehicle and the power grid. When the energy control module 102 needs to feed back energy to the power grid, the interaction module 104 may implement communication and interaction between the electric vehicle and the power grid. Through the interaction module 104, the user can choose to sink the electric energy from the electric automobile into the power grid, and participate in energy allocation or storage of the power grid.

Thus, the interaction module 104 is able to receive and process real-time monitoring data from the energy control module 102 and the monitoring module 103 and display it in a manner that is easy for the user to understand in order for the user to understand the operating state and performance of the system. Moreover, the interaction module 104 provides a user interface that allows a user to interact with the system and to operate and control as desired. Moreover, through the interaction module 104, the energy control module 102 can communicate and interact with the power grid, so as to realize the function of feeding back energy to the power grid by the electric automobile. Through the interaction module 104, a user can track the monitoring data and realize feedback and control of the system, and meanwhile, the electric automobile can interact with the power grid, so that a convenient user interface and the capability of realizing energy interaction are provided.

In some embodiments of the application, the energy conversion module 101 may be a bi-directional ACDC circuit and the energy control module 102 may be a bi-directional DCDC circuit.

That is, the energy conversion module 101 is a circuit for converting Alternating Current (AC) to Direct Current (DC). In the V2G system, the energy conversion module 101 is responsible for converting ac power from the power grid into dc power for charging the electric vehicle or for reverse power transmission. The energy control module 102 is a circuit for implementing bi-directional energy conversion between Direct Current (DC). The direct current energy converter is used for receiving direct current energy from the battery of the electric automobile and converting the direct current energy into direct current energy required by a power grid or converting the direct current energy of the power grid into direct current energy required by the battery of the electric automobile in a reverse direction. The energy control module 102 controls the input and output of energy by adjusting the conversion efficiency.

In addition, three phases are a power supply mode of the power system, and through three voltage waveforms which are mutually offset by 120 degrees, higher power transmission capacity is provided, load is balanced, materials and cost are saved, and a stable power supply is provided. Is widely used in industry and commerce to support the operation of high power equipment and motors.

The three-phase electric vehicle energy interaction control system is specifically described by the following embodiments.

Embodiment one:

Referring to fig. 2, fig. 2 is a circuit diagram of an electric vehicle energy interaction control according to an embodiment of the application. Fig. 2 shows a three-phase electric vehicle energy interaction control system 100 that includes an energy conversion module 101, an energy control module 102, a monitoring module 103, an interaction module 104, a power filtering module 105, a three-phase ac pre-charge module 106, and a switch driving module 107. The descriptions of the energy conversion module 101, the energy control module 102, the monitoring module 103, and the interaction module 104 are described above, and are not described herein.

Illustratively, the monitoring module 103 includes a control unit 1031, a voltage sampling unit 1032, and a current sampling unit 1033. The control unit 1031 is used for controlling and adjusting the voltage, current and power parameters of the system in the process of charging and discharging. The voltage sampling unit 1032 is used to monitor the voltage signals of the energy conversion module 101 and the energy control module 102 to convert them into digital signals for use by the control unit. The current sampling unit 1033 is used for monitoring the current signals of the energy conversion module 101 and the energy control module 102 to convert them into digital signals for the control unit 1031 to use.

Specifically, the control unit 1031 is configured to control and adjust voltage, current, and power parameters of the system during charging and discharging. It performs calculation and processing according to the real-time monitoring data, and controls and adjusts the working states of the energy conversion module 101 and the energy control module 102 through control operations.

For example, the control unit 1031 may employ a Digital Signal Processor (DSP). A DSP is a microprocessor that is dedicated to digital signal processing. The system has high-speed operation capability and rich quantity processing instruction sets, and can be used for monitoring data processing and control operation in real time. The control unit 1031 uses a DSP as a processing core. The DSP may receive digital signals acquired from the voltage sampling unit 1032 and the current sampling unit 1033 and calculate and adjust the voltage, current, and power of the energy conversion module 101 and the energy control module 102.

For example, when the voltage sampling unit 1032 detects that the output voltage of the battery of the electric vehicle is too high, the DSP can adjust the output power of the energy control module 102 by controlling the operation, so as to adapt to the requirements of the power grid, and ensure that the battery is not affected by the too high voltage.

In addition, the DSP may also perform other functions such as system status monitoring, fault detection, protection control, and the like. The system can make real-time decisions and feedback through an internal algorithm and control logic so as to ensure the safety, stability and high efficiency of the system.

Therefore, taking the DSP as the control unit 1031 may enable efficient data processing and accurate control operations, thereby improving performance and reliability of the electric vehicle energy management system.

Specifically, the voltage sampling unit 1032 is configured to monitor the voltage signals of the energy conversion module 101 and the energy control module 102 and convert them into digital signals for use by the control unit 1031. It samples and converts the voltage in the circuit and provides it to the control unit 1031 for voltage monitoring and control operations.

Specifically, the current sampling unit 1033 is configured to monitor the current signals of the energy conversion module 101 and the energy control module 102 and convert the current signals into digital signals for the control unit 1031 to use. It samples and converts the current in the circuit, converting the current value into a digital signal for the control unit 1031 to perform current monitoring and control operations.

The interaction module 104 includes, for example, a communication unit 1041, a display unit 1042, and an interface unit 1043. The communication unit 1041 is used for establishing a communication connection with a remote control module. The display unit 1042 is used for displaying the charge and discharge states of the electric automobile. The interface unit 1043 is used for establishing communication connection with the electric automobile.

That is, the communication unit 1041 is used to establish a communication connection with a remote control module. This means that the interactive module 104 can communicate with an external remote control module for data transmission and instruction exchange. The interactive module 104 may implement information exchange and remote control functions with external systems through a communication connection with the remote control module.

Specifically, the communication unit 1041 is used to establish a communication connection with a remote control module. This means that the interaction module 104 can communicate with an external remote control module (e.g. a mobile APP, applet, WEB side, etc.) for data transmission and instruction exchange. The interactive module 104 may implement information exchange and remote control functions with external systems through a communication connection with the remote control module.

Specifically, the display unit 1042 is used to display the charge and discharge states of the electric automobile. The method can display the real-time charging condition, the residual electric quantity and other related information of the electric automobile, provide an intuitive interface for a user, and facilitate the understanding and monitoring of the battery state of the electric automobile.

Specifically, the interface unit 1043 is used to establish a communication connection with an electric automobile. The interface is used for communicating with the electric automobile so as to transmit and receive related data and realize information interaction and control operation with the electric automobile.

Therefore, the communication unit 1041 establishes communication connection with the remote control module, and the interaction module 104 can remotely control and monitor the state of the electric automobile, so as to realize remote data transmission and instruction exchange. In addition, the display unit 1042 can display the charge and discharge states of the electric automobile in real time, and provide a visual information display interface, so that a user can conveniently know and monitor the state of the battery. In addition, the interface unit 1043 establishes communication connection with the electric automobile to realize data interaction and control operation with the electric automobile, and provides interfaces with the electric automobile for other systems or devices. The interaction module 104 realizes communication connection and data interaction functions with the remote control module and the electric vehicle through the communication unit 1041, the display unit 1042 and the interface unit 1043.

Illustratively, the power filtering module 105 includes a three-phase ac filtering unit 1051 and a dc filtering unit 1052. The three-phase ac filtering unit 1051 is configured to filter the high-frequency switching noise generated by the energy conversion module 101 to avoid the noise from being transmitted to the grid side. The input end of the dc filtering unit 1052 is connected to the output end of the energy control module 102, the output end of the dc filtering unit 1052 is connected to the battery of the electric vehicle, and the dc filtering unit 1052 is used for filtering the high-frequency switching noise generated by the energy control module 102, so as to avoid the noise from being transmitted to the battery side.

Specifically, the three-phase ac filtering unit 1051 is configured to perform filtering processing on the high-frequency switching noise generated by the energy conversion module 101, so as to avoid noise from being transmitted to the grid side. The purpose is to reduce the transmission of high frequency switching noise to the grid side. The energy conversion module 101, as a high frequency switching device, generates a certain amount of high frequency noise during the operation, and if it is directly transmitted to the grid side without filtering, it may cause interference and influence on the grid system. By using the three-phase ac filter unit 1051 for the filtering process, the high frequency switching noise can be reduced to a lower level, avoiding its transfer to the grid side, maintaining the stable operation of the grid and reducing interference to other devices.

Specifically, the input end of the dc filtering unit 1052 is connected to the output end of the energy control module 102, and the output end is connected to the battery of the electric vehicle. The dc filtering unit 1052 is used to filter the high frequency switching noise generated by the energy control module 102 to avoid the noise from being transferred to the battery side. This can reduce the transfer of high frequency switching noise to the battery side. The energy control module 102 acts as a high frequency switching device and generates a certain amount of high frequency noise during operation. If the power is directly transmitted to the battery side without filtering treatment, the power may cause interference and influence on the battery system of the electric automobile. By using the dc filter unit 1052 to perform the filtering process, the high-frequency switching noise can be reduced to a lower level, so as to avoid the interference to the battery of the electric vehicle, maintain the normal operation of the battery and prolong the service life of the battery. Meanwhile, the effect of noise on the battery is reduced, and the efficiency and stability of the whole energy system can be improved.

Accordingly, the power filtering module 105 can effectively filter out high frequency noise, harmonic components, and ripple signals in the power through the three-phase ac filtering unit 1051 and the dc filtering unit 1052. In addition, the filtering function of the power filtering module 105 can improve the quality of the electric energy, so that the energy control module 102 and the electric automobile battery can obtain stable and pure electric energy. In addition, the direct current filter unit 1052 can provide a stable and reliable direct current power supply for the battery of the electric automobile by deeply filtering the ripple in the direct current power supply, so that the safety and stability of the charging or discharging process of the battery are ensured. The power filtering module 105 functions in the system to filter the input power to provide high quality, stable ac and dc power to the energy control module 102 and the electric vehicle battery. This helps to improve the efficiency and reliability of the system.

Illustratively, an input of the three-phase ac pre-charge module 106 is connected to an output of the three-phase ac filtering unit 1051, and an output thereof is connected to an input of the energy conversion module 101, for controlling the output of the three-phase ac pre-charge module by the control unit 1031 to implement pre-charging of the energy conversion module when the power supply system is started.

That is, the input terminal of the three-phase ac pre-charge module 106 is connected to the output terminal of the three-phase ac filtering unit 1051, and the output terminal is connected to the input terminal of the energy conversion module 101. The main function is to control the output of the three-phase ac pre-charge module 106 by the control unit 1031 to effect pre-charging of the energy conversion module 101 when the power supply system is started.

Specifically, at the time of starting the power supply system, the three-phase alternating current precharge module 106 performs a precharge operation on the input terminal of the energy conversion module 101 by the control of the control unit 1031. This precharge process may allow for proper charge accumulation of the capacitor or the like so that the energy conversion module 101 can quickly reach a predetermined operating state prior to formal operation.

Therefore, by the precharge operation of the three-phase ac precharge module 106 to the energy conversion module 101, the electronic components in the energy conversion module 101 can be protected, and the overcurrent shock which may occur at the time of starting can be reduced. In addition, the precharge operation helps to ensure the normal operation of the energy conversion module 101, avoid an unstable condition caused by a sudden voltage change at the time of starting, and improve the reliability and operation stability of the whole power system. Moreover, by the precharge operation, the energy conversion module 101 can reach an ideal operation state before the formal operation, improving the efficiency and performance of the system start-up. The three-phase ac pre-charging module 106 performs a pre-charging operation on the energy conversion module 101 through control of the control unit 1031 to provide technical effects of protection, improvement of system reliability, and optimized start-up.

Illustratively, the input of the switch driving module 107 is connected to the control unit 1031, and the output thereof is connected to the energy conversion module 101, the energy control module 102, and the dc filtering unit 1052, respectively, for controlling the switching and executing actions of the respective modules.

That is, the input terminal of the switch driving module 107 is connected to the control unit 1031, and the output terminals are connected to the energy conversion module 101, the energy control module 102, and the dc filtering unit 1052, respectively. Its main function is to control the switching and execution actions of the various modules.

Specifically, the switch driving module 107 receives the control signal and interprets the instruction by being connected to the control unit 1031, and then performs switch control on the energy conversion module 101, the energy control module 102, and the dc filtering unit 1052 through its output terminals. The control operation of the switch may include opening, closing, switching, etc. for achieving coordinated operation between the respective modules.

Therefore, the switch driving module 107 performs accurate control on the switches of the energy conversion module 101, the energy control module 102 and the dc filtering unit 1052 through the input of the control unit 1031, so as to ensure the coordinated operation of the respective modules in the system. And, the switch driving module 107 can respond to the state of the module in real time according to the instruction of the control unit 1031, thereby realizing a fast and efficient switching operation. In addition, the switch driving module 107 controls the switch of the energy conversion module 101, the energy control module 102 and the direct current filtering unit 1052, so that not only can coordination work among the modules be realized, but also the stability and the safety of the system operation can be ensured. The switch driving module 107 achieves the technical effects of accurate control, real-time response and system coordination by being connected with the control unit 1031 and controlling the switching and executing actions of each module, so as to ensure the normal operation and the optimized performance of the whole system.

Embodiment two:

Referring to fig. 3, fig. 3 is a circuit diagram of an electric vehicle energy interaction control according to a second embodiment of the present application. Fig. 3 shows a three-phase electric vehicle energy interaction control system 100 that includes an energy conversion module 101, an energy control module 102, a monitoring module 103, an interaction module 104, a power filtering module 105, a three-phase ac pre-charge module 106, and a switch driving module 107.

The monitoring module 103 includes a control unit 1031, a voltage sampling unit 1032, and a current sampling unit 1033. The interaction module 104 includes a communication unit 1041, a display unit 1042, and an interface unit 1043. The power filtering module 105 includes a three-phase ac filtering unit 1051 and a dc filtering unit 1052.

The descriptions of the above modules are as shown in fig. 1A and fig. 2, and are not repeated here.

Illustratively, the energy conversion module 101 includes switching tubes (Q13, Q14, Q15, Q16, Q17, Q18), a capacitor C1, and an inductance (L1, L2, L3). The switching tubes (Q13, Q14, Q15, Q16, Q17, Q18) are used for controlling the on-off state of the current. The switching tube can be a power switching device such as a MOSFET or an IGBT and is used for realizing the energy conversion function. The capacitor C1 can play a role in energy storage and smoothing voltage in the energy conversion process. The inductors L1, L2 and L3 realize energy transfer and conversion in the energy conversion process through the establishment and disappearance of the magnetic field.

Illustratively, the energy control module 102 includes switching tubes (Q1-Q12), a capacitor C2, and an inductance L4. The switching tubes (Q1-Q12) are used for controlling the current flow in the circuit, and the on-off of the circuit is controlled by switching the switching state. In the energy control module 102, 12 different switching tubes, identified as Q1 to Q12, are included, which are used to implement switching operations in the circuit. Capacitor C2 is a device used to store electrical charge, and is capable of storing electrical power and releasing it when needed. In the energy control module 102, the capacitor C2 functions to store and smooth the supplied current. The inductor L4 is a device used to store energy, storing electricity by converting electric energy into magnetic energy. In the energy control module 102, the inductance L2 is used to control the variation and balance of the current.

These components work cooperatively to enable the energy control module 102 to control and regulate electrical energy. The switch tube is used for controlling the on-off state of the circuit, the capacitor C2 stores and smoothes the supplied current, and the inductor L4 is used for regulating the change of the current and keeping the stability of the circuit. The roles of these components are coordinated to ensure efficient energy transfer and proper energy management in the system.

Illustratively, the switch drive module 107 includes an ac relay drive circuit 1071, ACDC switching tube drive circuit 1072 (for controlling switching tubes Q13, Q14, Q15, Q16, Q17, Q18), DCDC switching tube drive circuit 1073 (for controlling switching tubes Q1 to Q4), series-parallel relay drive circuit 1074 (for controlling series-parallel relays K1 and K2), DCDC switching tube drive circuit 1075 (for controlling switching tubes Q5 to Q12), and dc relay drive circuit 1076, all connected to the control unit 1031.

Specifically, ac relay drive circuit 1071 is used to control the switching of three-phase ac pre-charge module 106. The circuit implements switching control of the three-phase ac pre-charge module 106 by being connected to a control unit 1031.

Specifically, ACDC switching tube drive circuit 1072 is used to control switching of energy conversion module 101. The circuit controls the switching operation of ACDC switching tubes in the energy conversion module 101 to achieve control of the energy conversion module.

Specifically, the DCDC switching tube driving circuit 1073 is used to control the switching of the energy control module 102. The circuit controls the switching operation of the DCDC switching tube in the energy control module 102, and realizes the control of the energy control module.

Specifically, the series-parallel relay drive circuit 1074 is used to control the series-parallel relays of the energy control module 102. The circuit controls the series-parallel switching operation of the series-parallel relays in the energy control module 102.

Specifically, the switching tube driving circuit 1075 is used to control switching of the DCDC control energy control module 102. The circuit controls the switching operation of the switching tubes in the DCDC control energy control module 102.

Specifically, the dc relay driving circuit 1076 is used to control the switching of the dc filter unit 1052. The circuit controls the switching operation of the dc relay in the dc filter unit 1052.

Thus, by the individual circuits of the switch drive module 107, precise control of the switches of the different modules can be achieved to ensure stable operation and optimal performance of the system. In addition, the control of the switch driving module 107 plays an important role in the switching operation of the energy conversion module 101 and the energy control module 102, so that efficient energy conversion and control can be realized, and the energy utilization efficiency can be improved. Moreover, by controlling the switches by the switch drive module 107, a fast response and adjustment can be achieved to meet the real-time demands of the system for energy conversion and control. The switch driving module 107 achieves the technical effects of accurate control, effective energy conversion and quick response by controlling the switching operations of the different modules, so as to improve the stability, efficiency and optimization performance of the whole system.

It should be noted that ACDC and DCDC are two different power conversion modes. ACDC is an ac-to-dc power conversion system that converts power from an ac power source into dc power for use. ACDC converters may convert an ac input to a constant dc output for use by a device. For example, the energy conversion module 101 may employ a bi-directional ACDC circuit. DCDC is a dc-to-dc power conversion scheme, i.e. converting one dc voltage into a different dc voltage to meet the requirements of different circuit components. The DCDC converter may implement a step-up and step-down conversion of the voltage between the input and the output to provide the required supply voltage level. For example, the energy control module 102 may employ a bi-directional DCDC circuit.

Illustratively, the voltage sampling unit 1032 includes an ac voltage sampling circuit 1032-1 that collects an input voltage of the energy conversion module 101, a BUS voltage sampling circuit 1032-2 that collects an output voltage of the energy conversion module 101, and a dc voltage sampling circuit 1032-3 that collects an output voltage of the dc filtering unit 1052.

That is, the voltage sampling unit 1032 includes an ac voltage sampling circuit 1032-1, a BUS voltage sampling circuit 1032-2, and a dc voltage sampling circuit 1032-3 for collecting input and output voltages of the energy conversion module 101 and output voltages of the dc filtering unit 1052.

Specifically, the ac voltage sampling circuit 1032-1 is used to collect the input voltage of the energy conversion module 101. It can measure the ac voltage value supplied by the input power to the energy conversion module 101 to understand the quality and stability of the power, and provide a reference for the subsequent energy conversion process. BUS voltage sampling circuit 1032-2 is used to collect the output voltage of energy conversion module 101. It measures the output voltage of the energy conversion module 101, i.e. the voltage level on the bus, to ensure the efficiency and quality of the energy conversion and to provide a correct voltage reference for the connection and coordination of the other modules. The dc voltage sampling circuit 1032-3 is configured to collect the output voltage of the dc filtering unit 1052. It monitors the voltage level output by the dc filtering unit 1052 to ensure the filter effect and the stability of the dc power supply.

Therefore, by collecting the input and output of the energy conversion module 101 and the output voltage of the dc filtering unit 1052, the voltage sampling unit 1032 can monitor the system in real time, ensure that the voltage is within a reasonable range, and provide a circuit protection and abnormality alarm mechanism. In addition, the voltage sampling unit 1032 provides accurate voltage values, which provide references for subsequent control and regulation, making the energy conversion and filtering process more accurate and stable. Moreover, through the collection of voltages, the voltage sampling unit 1032 may help detect and diagnose faults or anomalies that may exist in the system, providing powerful support for troubleshooting.

In a word, the voltage sampling unit 1032 realizes the technical effects of voltage monitoring and protection, accurate control and regulation, and fault detection and diagnosis through the collection work of the alternating voltage, BUS voltage and direct current voltage sampling circuit. This helps ensure system stability, performance optimization, and fault handling.

Illustratively, the current sampling unit 1033 includes an alternating current sampling circuit 1033-1 that collects an input current of the energy conversion module 101, a resonant current sampling circuit 1033-2 that collects a resonant current of the energy control module 102, and a direct current sampling circuit 1033-3 that collects an output current of the direct current filtering unit 1052.

That is, the current sampling unit 1033 includes an ac current sampling circuit 1033-1, a resonant current sampling circuit 1033-2, and a dc current sampling circuit 1033-3 for collecting an input current of the energy conversion module 101, a resonant current of the energy control module 102, and an output current of the dc filtering unit 1052.

Specifically, the ac current sampling circuit 1033-1 is used to collect the input current of the energy conversion module 101. The power conversion module 101 can measure the alternating current value supplied by an input power supply to the power conversion module to know the change condition of the current in the power conversion process, and provide reference for subsequent power conversion evaluation and control. The resonant current sampling circuit 1033-2 is used to collect the resonant current of the energy control module 102. The resonance current is a current formed at the resonance point, and plays an important role in resonance control and adjustment. By collecting and monitoring the resonance current, the resonance state can be mastered in real time, and subsequent control and adjustment operation can be assisted. The dc current sampling circuit 1033-3 is used for collecting the output current of the dc filtering unit 1052. It measures the current value output from the dc filtering unit 1052 to ensure the filter effect and the stability of the dc power supply.

Therefore, by collecting the input current of the energy conversion module 101, the resonance current of the energy control module 102, and the output current of the dc filtering unit 1052, the current sampling unit 1033 can monitor the system in real time to ensure that the current is within a reasonable range, providing circuit protection and an abnormality alarm mechanism. In addition, the current sampling unit 1033 provides accurate current values, provides references for subsequent control and regulation, and helps to achieve the accuracy and stability of the energy conversion and control process. Moreover, through the collection of the current, the current sampling unit can help to detect and diagnose possible faults or abnormal conditions in the system, and provides powerful support for fault detection.

In summary, the current sampling unit 1033 achieves the technical effects of current monitoring and protection, precise control and adjustment, and fault investigation and diagnosis through the collection work of the ac current, the resonant current and the dc current sampling circuit. This helps ensure system stability, performance optimization, and fault handling.

In some embodiments of the present application, the present application uses the control unit 1031 in order to adapt to different battery voltages, and the control unit 1031 may implement switching of the high-low voltage mode by controlling the switching states of the first and second series-parallel relays (K1 and K2) of the energy control module 102.

Referring to fig. 4, fig. 4 is a schematic diagram illustrating energy flow in a charging mode according to an embodiment of the application. The energy control module 102 is configured to charge a low voltage (e.g., 400V) battery platform when both the first series relay K1 and the second open series relay K2 are open. When both series relays K1 and K2 are closed, the energy control module 102 is used to charge a high voltage (e.g., 800V) battery platform.

That is, in fig. 4, the energy interaction system of the electric vehicle according to the present application needs to adapt to different battery voltages, and specifically, by controlling the state switching of the first serial-parallel relay K1 and the second disconnected serial-parallel relay K2, the energy control module 102 can charge the electric vehicle battery under different voltage platforms. Therefore, the electric automobile energy interaction system provided by the application can be compatible and provide a charging function for low-voltage and high-voltage battery platforms of different electric automobiles.

Referring to fig. 5, fig. 5 is a schematic diagram of energy flow in a grid-connected inversion mode according to an embodiment of the present application. The energy control module 102 may feed back the energy of the electric vehicle battery to the power grid, i.e., the electric vehicle battery discharges.

It should be noted that, the first series-parallel relay K1 and the second series-parallel relay K2 are turned on and off, and are only affected by the battery voltage of the electric vehicle, regardless of whether the energy interaction mode is charging or grid-connected inversion.

The voltage range of an electric vehicle may vary depending on the model and manufacturer design and specifications. Generally, the voltage range of electric vehicles is typically between 200V and 1000V. For example, the low-pressure mode range is 250V to 500V, and the high-pressure mode range is 500V to 1000V.

The following describes that the energy interaction control system of the three-phase electric automobile can support charging and discharging operations under different voltage platforms by taking 400V (as shown in fig. 6A and 6B) as a low-voltage mode and 800V (as shown in fig. 7A and 7B) as an example.

Referring to fig. 6A, fig. 6A is an equivalent circuit diagram of the energy control module according to the embodiment of the application, which works in the low-voltage charging or V2G mode. The corresponding electric car battery voltage is assumed to be a low voltage power battery at a 400V platform.

Illustratively, the energy control module 102 includes a bus-side full-bridge circuit 1021, a resonant capacitor C2 1022, a resonant inductance L4 1023, a transformer network 1024, a battery-side full-bridge network 1025, and a first series-parallel relay (a series-parallel relay may also be referred to as a high-low voltage control relay) K1 and a second series-parallel relay K2. Wherein the transformer network 1024 includes a first transformer (i.e., transformer 1) 1024-1 and a second transformer (i.e., transformer 2) 1024-2, and the battery-side full-bridge network 1025 includes a first full-bridge network (i.e., battery-side full-bridge circuit 1) 1025-1 and a second full-bridge network (i.e., battery-side full-bridge circuit 2) 1025-2.

Illustratively, the bus-side full-bridge circuit 1021 includes a switching tube Q1, a switching tube Q2, a switching tube Q3, and a switching tube Q4.

Illustratively, the first full-bridge network 1025-1 includes a switching tube Q5, a switching tube Q6, a switching tube Q7, and a switching tube Q8. The second full-bridge network 1025-2 includes a switching tube Q9, a switching tube Q10, a switching tube Q11, and a switching tube Q12.

When the system works in the first mode, a low-level driving signal is sent to the first series-parallel relay K1 and the second series-parallel relay K2 through the control unit 1031, so that the first series-parallel relay K1 and the second series-parallel relay K2 are continuously disconnected, primary windings of the first transformer 1024-1 and the second transformer 1024-2 are connected in series, namely the number of turns of the primary windings of the transformer network 1024 is 2Np. The first series-parallel relay K1 and the second series-parallel relay K2 are controlled to be in an off state all the time, so that the secondary side winding of the first transformer 1021-1 is connected to the first full-bridge network 1025-1 and the secondary side winding of the second transformer 1021-2 is connected to the second full-bridge network 1025-2, and the current is output to the electric automobile battery in parallel after passing through the first full-bridge network 1025-1 and the second full-bridge network 1025-2 respectively, so as to meet the charge and discharge requirements of the electric automobile battery working at a first preset voltage (for example 400V).

That is, when the system is in the first mode (e.g., low-voltage mode), the control unit 1031 sends a low-level driving signal to the first and second series-parallel relays K1 and K2, so that the first and second series-parallel relays K1 and K2 are continuously turned off. This is done to connect the primary winding of the first transformer 1021-1 and the primary winding of the second transformer 1024-2 in series, thereby forming a transformer network 1024 of voltage 2Np (where Np is the original number of transformer turns). This means that the primary winding turns of the transformer network 1024 are 2Np. Next, the secondary winding of first transformer 1024-1 would be independently connected to first full-bridge network 1025-1, while the secondary winding of second transformer 1024-2 would also be independently connected to second full-bridge network 1025-2. With this configuration, after the current passes through the first full-bridge network 1025-1 and the second full-bridge network 1025-2, they are output in parallel to the electric vehicle battery. The purpose of the design can realize lower voltage gain, and can meet the requirement that the electric automobile battery needs to be charged and discharged under the preset voltage (400V for example) when in operation.

For example, when the system is operated under a 400V battery voltage platform to meet charge and discharge requirements, the first and second series-parallel relays K1 and K2 remain in a normally open state. This may achieve a voltage equivalent transformation ratio of 2Np/Ns for the transformer network 1024 in the energy control module 102, where Np represents the primary winding turns and Ns represents the secondary winding turns. With this configuration, a lower voltage gain can be achieved, thus accommodating the charge and discharge requirements of the 400V battery voltage platform.

Therefore, by controlling the configuration of the first and second series-parallel relays K1 and K2 in the open state and the transformer network 1024 and the full-bridge network 1025 at the same time, the system can connect the primary windings of the two transformers in series in the low-voltage mode and output the current to the electric vehicle battery in parallel through the full-bridge network, so as to meet the charge and discharge requirements under the specified first preset voltage. Is beneficial to adapting to the working voltage requirements of different batteries of electric vehicles.

In the low-voltage mode shown in fig. 6A, the first series-parallel relay K1 and the second series-parallel relay K2 are simultaneously turned off, and the switching transistors Q1 to Q12 are controlled by the control unit 1031 and are in an operating state of the high-frequency switch. The switching signals of Q1 to Q12 in the charge and discharge state of the low-voltage battery are shown in fig. 6B, and fig. 6B is a timing chart of the switching signals of Q1 to Q12 in the charge and discharge state of the low-voltage battery in fig. 6A. Switching tubes Q1-Q12 are used to control the conversion of electrical energy between transformer network 1024 and full-bridge network 1025. Through the high-frequency switch operation, the electric energy can be effectively converted to meet the requirements of charging and discharging the battery of the electric automobile.

In summary, by maintaining the first series-parallel relay K1 and the second series-parallel relay K2 in a normally open state, the system can meet the charge-discharge requirements of a low voltage (e.g., 400V) battery voltage platform by adjusting the equivalent transformation ratio of the transformer network 1024. Meanwhile, the high-frequency switch operation controlled by the control unit 1031 realizes the electric energy conversion between the transformer network and the full-bridge network so as to meet the charging and discharging requirements of the electric automobile battery.

The low-voltage mode shown in fig. 6B includes a low-voltage charging mode and a low-voltage grid-connected discharging mode, specifically:

In the low voltage charging mode, the system may transfer electrical energy into a low voltage electric vehicle battery. Typically, this mode is applicable to low voltage battery platforms. In the low voltage charging mode, the system converts and transfers electrical energy in an appropriate manner to the low voltage battery of the electric vehicle for charging purposes.

In the low-voltage grid-connected discharging mode, a low-voltage electric vehicle battery is connected to a power grid, and stored electric energy is converted into alternating current through an inverter or other equipment and injected into the power grid. The mode can realize the interconnection of the low-voltage electric automobile battery and a household power grid or a public power grid, and can provide electric energy for the power grid or participate in energy management.

Referring to fig. 7A, fig. 7A is an equivalent circuit diagram of an energy control module according to an embodiment of the application, which operates in a high voltage mode. The corresponding electric car battery voltage is assumed to be a high voltage power battery under a 800V platform. The energy control module 102 includes a bus side full bridge circuit 1021, a resonant capacitor 1022, a resonant inductance 1023, a transformer network 1024, a battery side full bridge network 1025, and a first and second series-parallel relay K1, K2. Wherein transformer network 1024 includes a first transformer 1024-1 and a second transformer 1024-2, and battery side full-bridge network 1025 includes a first full-bridge network 1025-1 and a second full-bridge network 1025-2.

When the system works in the second mode, a high-level driving signal is sent to the first series-parallel relay K1 through the control unit 1031, and a low-level driving signal is sent to the second series-parallel relay K2, so that the first series-parallel relay K1 is continuously closed and the second series-parallel relay is continuously opened K2, and further the primary winding of the first transformer 1021-1 and the primary winding of the second transformer 1024-2 are connected in series, namely, the number of turns of the primary winding of the transformer network 1024 is 2Np. The first series-parallel relay K1 is controlled to be continuously in a closed state, so that the secondary side winding of the first transformer 1024-1 and the secondary side winding of the second transformer 1024-2 are connected in series and then connected to the battery side full-bridge network 1025, and the battery side full-bridge network 1025 is connected with the electric automobile battery to meet the charge and discharge requirement of the electric automobile battery when working at a second preset voltage (for example, 800V), wherein the second preset voltage is higher than the first preset voltage.

That is, when the system is in the second mode (e.g., high voltage mode), the control unit 1031 sends a high-level driving signal to the first series-parallel relay K1 and a low-level driving signal to the second series-parallel relay K2, so that the first series-parallel relay K1 is continuously closed and the second series-parallel relay K2 is continuously opened. In so doing, the primary winding of the first transformer 1021-1 and the primary winding of the second transformer 1024-2 may be connected in series to form a transformer network 1024 having a voltage of 2Np (where Np is the number of turns of the primary winding of the original transformer), such that the number of turns of the primary winding of the transformer network 1024 is 2Np. Next, the secondary winding of the first transformer 1024-1 is connected in series with the secondary winding of the second transformer 1024-2 and then connected to the battery side full bridge network 1025. The battery-side full-bridge network 1025 is connected to the electric vehicle battery to meet the charge and discharge requirements of the electric vehicle battery operating at a second predetermined voltage (e.g., 800V). By allowing current to pass through the battery-side full-bridge network 1025, conversion of electrical energy and charge-discharge operation of the electric vehicle battery is achieved. It should be noted that the second preset voltage is higher than the first preset voltage, that is, the system can meet the charge and discharge requirements of the higher voltage battery platform in the high voltage mode.

For example, when the system is operating at a 800V battery voltage platform to meet charge and discharge requirements, the first series-parallel relay K1 remains normally closed and the second series-parallel relay K2 remains open, such that a voltage equivalent transformation ratio of the transformer network 1024 in the energy control module 102 of 2Np/2Ns can be achieved, where Np represents the number of primary winding turns and Ns represents the number of secondary winding turns. With this configuration, a higher voltage gain can be achieved, thereby accommodating the charge and discharge requirements of the 800V battery voltage platform.

Therefore, by controlling the normally closed first series-parallel relay K1, the normally open second series-parallel relay K2, and the configuration of the transformer network 1024 and the full-bridge network 1025, i.e., the switching transistors Q7, Q8, Q9, Q10 are operated, Q5, Q6, Q11, Q12 are normally off, the system can connect the primary windings of the two transformers in series in the high voltage mode and output the current to the electric vehicle battery in series through the battery-side full-bridge network to meet the charge-discharge requirements at the specified second preset voltage. Is beneficial to adapting to the working voltage requirements of different batteries of electric vehicles.

In the high-voltage mode shown in fig. 7A, the switching transistors Q1 to Q4, Q7, Q8, Q9, and Q10 are controlled by the control unit 1031, and are in an operating state of the high-frequency switch for implementing electric energy conversion between the transformer network 1024 and the full-bridge network 1025, while the switching transistors Q5, Q6, Q11, and Q12 are in a state of being turned off for a long period of time, and do not participate in the electric energy conversion. The timing diagrams of the switching signals of Q1 to Q4, Q7, Q8, Q9, Q10 in the charge and discharge states of the high-voltage battery are shown in fig. 7B, and fig. 7B is a timing diagram of the switching signals of Q1 to Q4, Q7, Q8, Q9, Q10 in the charge and discharge states of the high-voltage battery in fig. 7A, so as to describe the switching states and the operating times of the high-voltage battery.

In summary, by maintaining the first series-parallel relay K1 in a normally closed state and the second series-parallel relay K2 in a normally open state, the energy control module 102 of the system may achieve a higher voltage gain to meet the charge-discharge requirements of a high voltage (e.g., 800V) battery voltage platform.

In addition, it should be noted that the present application is not limited herein, and the specific circuit connection and the operating state of the switching tube need to be adjusted according to a specific design and control strategy to achieve suitable power conversion and charge/discharge operation.

The high-voltage mode shown in fig. 7B includes a high-voltage charging mode and a high-voltage grid-connected discharging mode, specifically:

In the high voltage charging mode, the system may transfer electrical energy into a high voltage electric vehicle battery. Typically, this mode is applicable to high voltage battery platforms. In the high voltage charging mode, the system converts and transfers electrical energy in an appropriate manner to the high voltage battery of the electric vehicle for charging purposes.

In the high-voltage grid-connected discharge mode, a high-voltage electric vehicle battery is connected to a power grid, and stored electric energy is converted into alternating current through an inverter or the like and injected into the power grid. This mode allows for interconnection of the high voltage battery system with the home or public power grid and for providing power to the grid or for participating in energy management.

Fig. 7A shows an equivalent circuit diagram in the high-voltage mode in which the first series-parallel relay K1 is turned on (i.e., the first series-parallel relay K1 is closed). Fig. 8A shows an equivalent circuit diagram in the high-voltage mode in which the second series-parallel relay K2 is turned on (i.e., the second series-parallel relay K2 is closed).

Referring to fig. 8A, fig. 8A is an equivalent circuit diagram of an energy control module according to an embodiment of the present application, wherein secondary side switching transistors Q5, Q6, Q11, Q12 are operated, and Q7, Q8, Q9, Q10 are normally turned off.

When the system works in the second mode, a low-level driving signal is sent to the first series-parallel relay K1 through the control unit 1031, and a high-level driving signal is sent to the second series-parallel relay K2, so that the first series-parallel relay K1 is continuously opened and the second series-parallel relay K2 is continuously closed, and further the primary winding of the first transformer 1021-1 and the primary winding of the second transformer 1024-2 are connected in series, namely, the number of turns of the primary winding of the transformer network 1024 is 2Np. The second series-parallel relay K2 is controlled to be continuously in a closed state, so that the secondary side winding of the first transformer 1024-1 and the secondary side winding of the second transformer 1024-2 are connected in series and then connected to the battery side full-bridge network 1025, and the battery side full-bridge network 1025 is connected with the electric automobile battery to meet the charging and discharging requirements of the electric automobile battery working at a second preset voltage (for example, 800V).

Therefore, under the 800V battery voltage platform, by controlling the second series-parallel relay K2 to be normally closed and the first series-parallel relay K1 to be normally open, the voltage equivalent transformation ratio of the transformer network 1024 in the energy control module 102 is 2Np/2Ns, so that higher voltage gain can be realized, and further the charge and discharge requirements of the 800V battery voltage platform can be satisfied.

In addition, as shown in fig. 8A, the equivalent circuit of the second series-parallel relay K2 when it is closed is that the switching transistors Q1 to Q4, Q5, Q6, Q11, Q12 are controlled by the control unit and are in the operation state of the high-frequency switch, while Q7, Q8, Q9, Q10 are in the long-term off state, and the switching signal timing diagrams of Q1 to Q4, Q5, Q6, Q11, Q12 in the charge-discharge state of the high-voltage battery are shown in fig. 8B.

From this, it can be seen that, by the above-mentioned manner of alternately turning on the first series-parallel relay K1 and the second series-parallel relay K2 shown in fig. 7A and 8A, the secondary side switching tubes Q5, Q6, Q11, Q12 and Q7, Q8, Q9, Q10 of the energy control module alternately operate, so that the conduction operation time of each of the switching tubes Q5 to Q12 in the whole life cycle of the system tends to be consistent, and further the problem of degradation of the service life of the switching tube due to overlong operation time of a part of the switching tubes can be avoided.

That is, by alternately using different groups of switching tubes, it is ensured that they share the time of conducting operation throughout the life of the charging stake, thereby avoiding the situation that some switching tubes experience life deterioration due to long-term operation. The reliability and stability of the overall system can be improved.

In other embodiments of the present application, please refer to fig. 9A and 9B, wherein fig. 9A is a circuit diagram of an energy control module according to another embodiment of the present application, and fig. 9B is a circuit diagram of an energy control module according to another embodiment of the present application. Fig. 9A and 9B are derivative versions of the energy control module of the present application, respectively.

Wherein fig. 9A only retains the scheme of the first series-parallel relay K1. When the first series-parallel relay K1 is closed (on state), the circuit operates in a high-voltage mode; when the first series-parallel relay K1 is open (non-conductive state), the circuit operates in a low-voltage mode. This scheme achieves switching between the high-low voltage modes by controlling the on or off state of the first series-parallel relay K1.

Wherein fig. 9B only retains the scheme of the second series-parallel relay K2. When the second series-parallel relay K2 is closed (on state), the circuit operates in the low-voltage mode; when the second series-parallel relay K2 is turned off (non-conductive state), the circuit operates in the high-voltage mode. This scheme realizes switching between the high-low voltage modes by controlling the on or off state of the second series-parallel relay K2.

It will be appreciated that fig. 9A and 9B illustrate two derivative schemes, one of which retains only the first series-parallel relay K1 and the other retains only the second series-parallel relay K2. The schemes can switch between high-voltage and low-voltage modes by closing different relays through the switch so as to adapt to different charging requirements.

The switching transistor in the present application may use a MOSFET (metal oxide semiconductor field effect transistor) as the power switch. The power switch device is a common power switch device and has the advantages of low switching loss, high switching speed, good thermal characteristics and the like. IGBTs (insulated gate bipolar transistors) may also be used as power switches. An IGBT is a transistor and MOSFET integrated device with a low on-voltage drop and high switching speed, suitable for high voltage and high current applications.

Further, the energy control module 102 may use an isolated LLC circuit. LLC circuit is a common DCDC topology, and consists of three resonant inductors, two capacitors and two switches. The circuit can realize efficient energy conversion and has good electromagnetic compatibility and adjustable output characteristics. Circuits such as CLLC (Capacitor-Inductor-Inductor-Capacitor), CLLLC (Capacitor-Inductor-Lossless Inductor-Capacitor), and DAB (Dual Active Bridge) may also be used. The topological structures have different characteristics and application ranges, and the proper topological structure can be selected according to specific design requirements and application scenes.

In summary, the three-phase electric vehicle energy interaction control system can also solve the problem of supporting charging and discharging operations under different voltage platforms. The system can adapt to the charging and discharging requirements on different voltage platforms through the coordination work of the energy conversion module and the energy control module, and achieves adaptability and compatibility.

The three-phase electric vehicle energy interaction control method provided by the application is described below, and the three-phase electric vehicle energy interaction control method described below and the three-phase electric vehicle energy interaction control system described above can be correspondingly referred to each other.

Referring to fig. 10, fig. 10 is a flowchart of a three-phase electric vehicle energy interaction control method provided by the application. The energy interaction control method for the three-phase electric automobile is applied to the energy interaction control system for the three-phase electric automobile according to any embodiment, and comprises the following steps:

Step 810, in a charging mode, the control unit adopts a control strategy of double closed loops of direct current bus voltage and alternating current for the energy conversion module; and the control unit adopts a double-loop competition control strategy of a voltage closed loop and a current closed loop for the energy control module.

The control unit adopts a control strategy of direct-current bus voltage and alternating-current double closed loops for the energy conversion module. That is, in the energy conversion module, a control method that simultaneously controls the dc bus voltage and the ac current is used.

Specifically, the closed-loop control of the dc bus voltage is used to regulate the dc bus voltage output by the energy conversion module to reach a given target value. The feedback signal of the DC bus voltage is obtained through the voltage acquisition circuit, compared with a preset target value, and then a corresponding control signal is calculated through a closed-loop control algorithm (such as a PI control algorithm or a PID control algorithm) so as to control the operation of the energy conversion module, so that the output DC bus voltage is stabilized near the target value. Among them, PI (Proportional-Integral) control algorithm is a feedback control algorithm for adjusting the difference between the output of the system and the desired value. A PID (Proportional-Integral-Derivative) control algorithm is a feedback control algorithm applied to an automatic control system, and adjusts the difference between the output of the system and a desired value through three parts of Proportional, integral and Derivative.

The closed loop control of the alternating current is used for adjusting the alternating current output by the energy conversion module, so that the alternating current meets the requirements of a system. The feedback signal of the alternating current is obtained through the acquisition circuit, compared with a preset target value, and a corresponding control signal is calculated through a closed-loop control algorithm (such as a PI control algorithm or a PID control algorithm) so as to adjust the operation of the energy conversion module, so that the output alternating current is stabilized near the target value.

Therefore, by adopting two double closed-loop control strategies of direct current bus voltage and alternating current, the direct current bus voltage and the alternating current output by the energy conversion module can be accurately controlled, so that the requirements of a system are met, and the stable operation of the energy conversion module is ensured.

It should be noted that, in the control strategy, the present application uses a control method of double closed loop Proportional Integral (PI) or proportional, integral and derivative (PID) to control the output duty ratio of the switching tube, so as to adjust the amplitude and phase of the inductor current to control the output voltage.

Specifically, the control unit adopts a voltage closed loop and current closed loop double-loop competition control strategy for the energy control module. That is, when the energy control module is controlled, the control of the output voltage and the output current is performed simultaneously. The control strategy includes two loops: a voltage loop and a current loop.

A voltage ring: a voltage error signal is generated by detecting the output voltage and comparing it with a set target value. This error signal is input to a closed loop controller, which controls the energy control module by adjusting a control parameter to stabilize its output voltage around a set target value.

Current loop: the current loop controls the output current. A current error signal is generated by detecting the actual output current and comparing it with the target current. The current error signal is input into the closed loop controller, and the energy conversion module is controlled to adjust the magnitude of the output current so as to meet the required current requirement.

Therefore, under the control strategy of double-loop competition, the voltage loop and the current loop work simultaneously, and the operation of the energy control module is adjusted according to the error signal through the corresponding closed-loop controller, so that the accurate control of the output voltage and the output current is realized. By adopting the control strategy of double-loop competition, the energy control module can only use one loop in steady-state operation, and the other loop is in a saturated output state. This strategy is capable of effectively controlling voltage and current during energy control and provides stable, efficient energy control performance.

Step 820, in the grid-connected inversion mode, the control unit adopts a comprehensive control strategy of active power control, reactive power control, fault ride-through control, anti-islanding control and PFC bus voltage regulation control for the energy conversion module; and the control unit adopts a double-loop competition control strategy of a voltage closed loop and a current closed loop for the energy control module.

Specifically, in the grid-connected inversion mode, the control unit uses a comprehensive control strategy to control the energy conversion module. This includes active, reactive power control, fault ride through control, anti-islanding control, and PFC bus voltage regulation control. Meanwhile, the control unit also uses a double-loop competition control strategy to control the energy control module, wherein a voltage closed loop and a current closed loop are used.

Therefore, through the comprehensive control strategy, the energy conversion module can be subjected to accurate power control, fault ride through processing, system island state entering prevention and PFC bus voltage regulation optimization. And the energy control module is subjected to closed-loop control by adopting a double-loop competition control strategy, so that more accurate and stable control can be realized according to feedback information of voltage and current. Therefore, the application of the control strategies can improve the system stability, the power control precision and the satisfaction degree of the power grid requirements in the grid-connected inversion mode.

Specifically, in the grid-connected inversion mode, the control unit adopts a voltage closed loop and current closed loop double-loop competition control strategy for the energy control module.

In the energy control module, a control strategy adopting voltage and current double-loop competition is similar to the charging mode, only one loop works in steady-state operation, and the other loop is in a saturated output state. The voltage closed loop and the current closed loop are respectively calculated, the calculation results are compared, and the smaller result is used as an output result. And adjusting the PWM signal frequency of the energy control module circuit according to the output result to realize accurate control.

The charging mode and the grid-connected inversion mode are two important modes for realizing the V2G mode. V2G refers to connecting an electric vehicle to a power grid, and through bidirectional energy interaction, the electric vehicle may inject electric energy into the power grid or obtain electric energy from the power grid to participate in scheduling and balancing of a power system. Specifically, the charging mode refers to transferring energy from a power grid into an electric vehicle battery for charging. In this mode, electrical energy flows to the battery of the electric vehicle, storing the electrical energy for later use. The grid-connected inversion mode refers to converting direct-current electric energy in a battery of an electric automobile into alternating-current electric energy through energy conversion equipment (such as an inverter), and injecting the alternating-current electric energy into a power network. In this mode, the electric vehicle may send the stored energy to the grid as useful electrical energy. In the V2G, the electric automobile can become an adjustable load in a power system, and bidirectional exchange of electric energy is realized.

The above steps 810 and 820 are specifically described below by way of an embodiment.

In the step 810, the step of the control unit adopting the control strategy of the dc bus voltage and the ac current dual closed loop for the energy conversion module includes:

In step 810A, the control unit performs closed-loop control on the voltage through the voltage loop regulator according to the difference between the dc bus voltage and the set reference voltage, and calculates an ac reference current according to the ac input voltage sampling signal. Meanwhile, the control unit calculates the current error through the current loop regulator to generate a PWM duty ratio, and then the state of a switching tube of the energy conversion module is regulated through the PWM modulator so as to realize accurate control of alternating current input current and direct current bus output voltage.

Specifically, this step 810A includes the following steps 811A to 815A:

Step 811A, collecting the dc bus voltage by the voltage sampling unit and comparing the dc bus voltage with a given reference voltage to output a voltage error signal, which is then input into the voltage loop regulator for closed loop control of the voltage loop.

The reference voltage is a given reference voltage value and is used for comparing with the collected direct current bus voltage. The voltage error signal is a difference signal obtained by comparing the dc bus voltage with the reference voltage.

Step 812A, multiplying the result of the calculation output by the voltage loop regulator by the ac input voltage sampling signal of the energy conversion module to obtain an ac reference current.

The reference alternating current not only contains the amplitude and phase information of the input voltage, but also contains the information of the output voltage.

In step 813A, the current sampling unit collects the inductor current, and compares the inductor current with the reference current to output a current error.

In step 814A, the current error is calculated using a closed loop control algorithm to generate a PWM (pulse width modulation) duty cycle for the energy conversion module.

Step 815A, the PWM modulator is adjusted according to the PWM duty ratio, and the state of a switching tube of the energy conversion module is controlled, so that the control of the alternating current input current and the direct current bus output voltage is realized.

It can be seen that the above steps 811A to 815A obtain a voltage error signal by collecting the dc bus voltage and comparing it with a given reference voltage. In this way, the dc bus voltage can be accurately monitored and controlled to ensure that it is stable around a preset value. And multiplying the voltage error signal by the alternating input voltage of the energy conversion module to obtain an alternating reference current. Thus, the required alternating input current can be calculated according to the voltage error, and a reference is provided for the current control of the next step. By comparing the inductor current with an ac reference current, a current error is generated and calculated using a closed loop control algorithm. Therefore, the PWM duty ratio of the energy conversion module can be dynamically adjusted according to the difference between the actual current and the reference current, so that more accurate current control is realized. And adjusting the PWM modulator according to the calculated PWM duty ratio, and controlling the state of a switching tube of the energy conversion module. The energy conversion module can be effectively controlled to output the alternating current input current and the direct current bus output voltage which meet the requirements.

In some embodiments of the present application, in step 810, the step of the control unit adopting a voltage closed loop and current closed loop dual loop contention control strategy for the energy control module includes:

Step 810B, in steady state operation, only one loop is active, the other loop being in a saturated output state; respectively performing voltage closed loop calculation and current closed loop calculation, comparing calculation results of the voltage closed loop calculation and the current closed loop calculation, and selecting a smaller calculation result as an output result of the loop; and adjusting the PWM signal frequency of the energy control module according to the output result to realize control.

Specifically, this step 810B includes the following steps 811B through 814B:

In step 811B, only one loop is operating while in steady state operation, the other loop is in saturated output.

Wherein steady state operation is a process operating in steady state, with various parameters of the system remaining substantially unchanged. The saturated output state refers to when the output result of one loop has reached its limit, which is referred to as a saturated output state.

Step 812B, performing voltage closed loop calculation and current closed loop calculation respectively to obtain respective control results.

The voltage closed loop refers to a loop for performing closed-loop control on output voltage. The current closed loop is a loop for performing closed loop control on the output current.

Step 813B, comparing the calculation results of the voltage closed loop and the current closed loop, and selecting a smaller calculation result as the output result of the loop.

Specifically, a smaller calculation result is selected as the output result of the selected loop. To ensure a smaller control amount in the calculation result is selectively output to avoid unnecessary overshoot.

Step 814B, adjusting the frequency of the PWM signal of the energy control module according to the output result.

In particular, the modulation of the PWM signal will affect the switching tube state of the energy conversion module, thereby regulating the control of the output voltage and current.

Thus, in steps 811B through 814B, only one loop is operating and the other loop is in saturated output during steady state operation. Thus, interference and collision generated by simultaneously operating two loops can be avoided, and the running stability of the system is ensured. And, through carrying out the voltage closed loop and the current closed loop calculation respectively, the respective calculation results are obtained. The two closed loop calculations are then compared and the smaller calculation is selected as the output of the loop. Therefore, the operation of the energy control module can be dynamically adjusted according to the actual conditions of the output voltage and the output current in steady-state operation, so that more accurate control is realized. And, the frequency of the PWM signal of the energy control module is adjusted according to the output result. The switching tube state and the output waveform characteristics of the energy conversion module can be controlled by adjusting the frequency of the PWM signal so as to meet the requirements of a system.

Referring to fig. 11, fig. 11 is a schematic diagram of a control strategy in a grid-connected inversion mode according to an embodiment of the present application. In some embodiments of the present application, in step 820, the step of the control unit adopting the integrated control strategy of active power control, reactive power control, fault ride through control, anti-islanding control, and PFC bus voltage regulation control for the energy conversion module in the grid-connected inversion mode includes:

and step 820A, setting target active power and reactive power, performing active power control and reactive power control to meet requirements, performing ride-through control under fault conditions to ensure safe operation of the system, monitoring the power grid connection state and preventing the power grid from entering an island state, and optimizing charge and discharge efficiency through PFC bus voltage regulation control.

Specifically, this step 820A includes the following steps 821A to 825A:

in step 821A, target active power and reactive power are set.

Specifically, in the V2G mode, the required active power and reactive power are set according to the needs of the user or system. These target powers are the reference values that the control unit needs to achieve in the subsequent steps.

And 822A, performing active and reactive power control to meet the power requirement in the grid-connected inversion mode.

Specifically, PQ control is a control method for regulating active and reactive power in an electrical system. P represents Active Power, Q represents Reactive Power. Active power refers to the portion of the current that produces useful power in the circuit, typically expressed as forward power (positive value). Reactive power refers to the portion of the current that produces no work in the circuit, typically expressed as reverse power (negative).

Specifically, in the V2G mode, the output current and voltage are adjusted by controlling the state of the power devices (e.g., switching tubes) in the energy conversion module of the system, so as to achieve precise active and reactive power control. And the monitoring module is used for monitoring the requirements and the state of the power grid, and the control unit is used for carrying out switch control on the power device, so that the system can provide active power and reactive power with specific values according to the requirements.

And step 823A, performing fault ride-through control, and processing according to the low voltage ride-through and high voltage ride-through requirements of the power grid so as to ensure the fault ride-through function of the system under different power grid standards.

Specifically, fault crossing refers to that in an electric power system, when an abnormal condition of the grid voltage (such as low voltage, high voltage, etc.) occurs, the system can be quickly switched to a suitable working state through a protection device to cope with the grid change. Low voltage ride through and high voltage ride through refer to the need for a system that can operate stably and ensure safe operation of the system when the grid voltage is below or above the normal range. The fault crossing under different power grid standards refers to the fact that the system can perform corresponding fault crossing when the system is suitable for power standards and specification requirements of different regions or countries.

Specifically, through monitoring the power grid voltage, when detecting fault conditions such as low voltage or high voltage, the control unit can cut off the connection with the power grid fast, and protection system and electric automobile avoid receiving the unusual influence of electric wire netting. Meanwhile, according to different power grid standard requirements, the control unit can correspondingly adjust and adapt to the fault ride-through process.

Step 824A, implementing anti-islanding control, monitoring a power grid connection state, and stopping the grid-connected inversion operation mode when the direct current pile is separated from the power grid, so as to avoid the electric automobile from entering the islanding state.

In particular, anti-islanding refers to a state in which an independent operation of an "island" is avoided due to a certain part of the system being separated from the operation of the main grid in order to ensure stable operation of the power system. The off-grid state refers to the state that the direct current pile is separated from the power supply of the power grid.

Specifically, when the direct current pile is separated from the power grid state, the control unit can immediately stop the V2G working mode so as to avoid the electric automobile from forming an island state. By monitoring the grid connection status and the operational mode of the system, the control unit will quickly switch operational modes when it detects that the system is disconnected from the grid and ensure that the system will not continue to supply power to the grid or absorb grid energy.

Step 825A, performing PFC bus voltage regulation control, and regulating the voltage of the PFC bus according to the change of the battery voltage of the electric automobile so as to optimize the charge/discharge efficiency of the system.

Specifically, PFC BUS refers to BUS bar BUS in the system for connecting the grid and the system. Charge/discharge efficiency refers to the efficiency with which the system charges or discharges electrical energy from the battery. PFC (Power Factor Correction ) is a technique that approximates the power factor to 1 by adjusting components in the circuit.

The PFC bus voltage regulation control refers to a control method for optimizing charge/discharge efficiency by regulating PFC bus voltage in a system. PFC bus is an important component in the system for connecting the grid and the energy conversion module of the system. In the V2G (electric vehicle to grid) mode, the system needs to charge or discharge control the PFC bus according to the electric vehicle charging or discharging requirements to achieve high-efficiency energy conversion and optimize energy utilization. The purpose of the PFC bus voltage regulation control is to regulate the PFC bus voltage during charging and discharging according to the change in the battery voltage, so as to maintain it within a proper range, to improve the charging/discharging efficiency and to ensure the system stability. By timely adjusting the voltage of the PFC bus, energy loss can be reduced, and meanwhile, the condition of different battery voltages can be well adapted.

Therefore, the application of the PFC bus voltage regulation control strategy can help optimize the charging/discharging process of the system in the V2G mode, improve the energy conversion efficiency, reduce the energy waste and ensure the stable operation of the system.

Specifically, the control unit monitors the battery voltage in real time and adjusts the voltage of the PFC bus according to the change of the battery voltage. This can be achieved by adjusting the connection between the dc pile battery and the PFC bus, controlling the switching state of the power device, etc. The purpose of the voltage regulation control is to keep the voltage of the PFC bus within a proper range so as to optimize the charge/discharge efficiency of the system and improve the energy conversion efficiency.

Therefore, through the steps 821A to 825A, the control strategies of setting the target power, PQ control, fault ride through control, anti-islanding control, PFC bus voltage regulation control, etc. in the energy conversion module can ensure that the system satisfies the power demand in the V2G mode, adapts to the power grid variation, avoids islanding state, and optimizes the charging/discharging process.

In some embodiments of the present application, in step 820, the dual-loop competition control strategy of the control unit for the energy control module using the voltage closed loop and the current closed loop in the grid-connected inversion mode includes:

Step 820B, in steady state operation, only one loop is active, the other loop is in saturated output state; respectively performing voltage closed loop calculation and current closed loop calculation, comparing calculation results of the voltage closed loop calculation and the current closed loop calculation, and selecting a smaller calculation result as an output result of the loop; and adjusting the PWM signal frequency of the energy control module according to the output result to realize control.

Specifically, this step 820B includes the following steps 821B to 824B:

in step 821B, only one loop is operating and the other loop is in saturated output during steady state operation.

Step 822B, performing voltage closed loop calculation and current closed loop calculation respectively to obtain respective control results;

Step 823B, comparing the calculation results of the voltage closed loop and the current closed loop, and selecting a smaller calculation result as an output result of the loop.

Step 824B, adjusting the frequency of the PWM signal of the energy control module according to the output result.

In the steps 821B to 824B, in the grid-connected inversion mode, a voltage closed loop and a current closed loop double-loop competition control strategy is adopted in the control of the energy control module. Similar to the charge mode described above for steps 811B through 814B, only one loop is operating during steady state operation and the other loop is in saturated output. The voltage closed loop and the current closed loop are respectively calculated, the calculation results are compared, and the smaller result is used as an output result. And adjusting the PWM signal frequency of the energy control module according to the output result to realize accurate control.

It will be appreciated that the control strategy shown in fig. 11 in the grid-tie inversion mode includes control of the energy control module 102 and control of the energy conversion module 101:

Control of the energy control module 102: the control part comprises two links of a voltage closed loop and a current closed loop. The power control on the power control module 102 side is engaged in a double loop contention manner. That is, the regulation and control of the power of the energy control module 102 is achieved by closed loop control of the voltage and current.

Control of the energy conversion module 101: the control comprises active power control, reactive power control (PQ control), fault ride through control, PFC bus voltage regulation control, island prevention control and other functions. Among them, active and reactive power control (PQ control) is control of active and reactive power/current at the time of grid connection in V2G mode by PQ control. The fault ride-through control can meet the requirements of low voltage ride-through, high voltage ride-through and the like under different power grid standards in the V2G mode. The PFC bus voltage regulation control is to regulate the PFC bus voltage according to the change of the battery voltage by regulating the PFC bus voltage so as to optimize the charging/discharging efficiency of the direct current pile. The anti-islanding control is to stop the V2G working mode under the DC pile mesh-off state, so that the electric automobile is prevented from working under the islanding state.

Therefore, the control method realizes the regulation and control of the power, the current and the voltage of the three-phase bidirectional direct current pile in a V2G (bidirectional energy interaction of a vehicle to a power grid) mode, has the protection functions of fault ride-through, island prevention and the like, and optimizes the charge/discharge efficiency through PFC bus voltage regulation control.

In summary, the application provides a three-phase electric vehicle energy interaction control system and a control method thereof, which solve the problems that an electric vehicle realizes a V2G mode and supports charging and discharging operations under different voltage platforms. The differences of the application compared with the prior art include:

first, an energy conversion module, an energy control module, and a control method thereof are introduced.

Specifically, a charging pile bidirectional energy conversion module, an energy control module and a control circuit thereof are introduced into the direct current pile scheme, so that the three-phase bidirectional V2G direct current pile control method is realized. This means that bidirectional energy interaction can be carried out between the electric automobile and the power grid, the electric automobile can be charged by the power grid through the direct current pile, and the electric automobile can be discharged to the power grid through the direct current pile.

Second, active, reactive power control, fault ride-through, and anti-islanding control are introduced.

The application introduces control methods such as active power control, reactive power control, fault ride-through, island prevention control and the like into the direct current pile V2G scheme. This means that the electric vehicle can accept the dispatching of the grid and transfer reactive power back to the grid. Meanwhile, when the power grid voltage is abnormal, the support and recovery of the system to the power grid voltage can be ensured through anti-islanding control.

Third, different battery voltage platforms are supported.

Aiming at the limitation that the traditional direct-current charging pile cannot support a high-voltage (for example, 800V) battery platform, the application introduces a bidirectional energy control module and a control method thereof. The application can adapt to electric vehicles with different battery voltage platforms, and realize the functions of charging and power grid interaction.

Compared with the prior art, the application has more functions and control means, including bidirectional energy transmission, active power control, reactive power control, anti-islanding control and the like, and simultaneously solves the problem that the traditional direct current charging pile cannot support a high-voltage battery platform.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A three-phase electric vehicle energy interactive control system, the system comprising:

2. The three-phase electric vehicle energy interactive control system according to claim 1, wherein the monitoring module comprises:

3. The three-phase electric vehicle energy interaction control system of claim 2, wherein the energy control module comprises a bus-side full-bridge circuit, a resonant capacitor, a resonant inductance, a transformer network, a battery-side full-bridge network, and first and/or second series-parallel relays, wherein the transformer network comprises a first transformer and a second transformer, and the battery-side full-bridge network comprises a first full-bridge network and a second full-bridge network.

4. The three-phase electric vehicle energy interaction control system according to claim 3, wherein when the system works in a first mode, a low-level driving signal is sent to the first series-parallel relay and the second series-parallel relay through the control unit respectively, so that the first series-parallel relay and the second series-parallel relay are continuously disconnected, further a primary side winding of the first transformer and a primary side winding of the second transformer are connected in series, a secondary side winding of the first transformer is connected to the first full-bridge network and a secondary side winding of the second transformer is connected to the second full-bridge network, and current is output to the electric vehicle battery in parallel after passing through the first full-bridge network and the second full-bridge network respectively, so as to meet charge and discharge requirements of the electric vehicle battery working at a first preset voltage.

5. The three-phase electric vehicle energy interaction control system according to claim 4, wherein when the system is operated in the second mode, a high-level driving signal is sent to the first series-parallel relay and a low-level driving signal is sent to the second series-parallel relay through the control unit, so that the first series-parallel relay is continuously closed and the second series-parallel relay is continuously opened, so that the primary winding of the first transformer and the primary winding of the second transformer are connected in series, and the first series-parallel relay is controlled to be continuously in a closed state, so that the secondary winding of the first transformer and the secondary winding of the second transformer are connected in series and then connected to the battery-side full-bridge network, and the battery-side full-bridge network is connected with the electric vehicle battery to meet the charge-discharge requirement of the electric vehicle battery operated at a second preset voltage, wherein the second preset voltage is higher than the first preset voltage.

6. The three-phase electric vehicle energy interaction control system according to claim 3, wherein when the system is operated in the second mode, a low-level driving signal is sent to the first series-parallel relay and a high-level driving signal is sent to the second series-parallel relay through the control unit, so that the first series-parallel relay is continuously opened and the second series-parallel relay is continuously closed, the second series-parallel relay is controlled to be continuously in a closed state, so that the primary winding of the first transformer and the primary winding of the second transformer are connected in series, the secondary winding of the first transformer and the secondary winding of the second transformer are connected in series and then connected to the battery-side full-bridge network, and the battery-side full-bridge network is connected with the electric vehicle battery to meet the charging and discharging requirements of the electric vehicle battery operated at a second preset voltage.

7. The three-phase electric vehicle energy interactive control system according to claim 1, wherein the system further comprises:

The power supply filtering module comprises a three-phase alternating current filtering unit and a direct current filtering unit, wherein the three-phase alternating current filtering unit is used for filtering high-frequency switching noise generated by the energy conversion module so as to avoid noise from being transmitted to a power grid side; the input end of the direct current filtering unit is connected with the output end of the energy control module, the output end of the direct current filtering unit is connected with the battery of the electric automobile, and the direct current filtering unit is used for filtering high-frequency switching noise generated by the energy control module so as to avoid noise from being transmitted to the battery side.

8. The three-phase electric vehicle energy interactive control system according to claim 7, wherein said system further comprises:

9. The three-phase electric vehicle energy interactive control system according to claim 1, wherein the system further comprises:

10. The energy interactive control system of claim 3, wherein the interactive module comprises a communication unit, a display unit and an interface unit, and the communication unit is used for establishing communication connection with a remote control module; the display unit is used for displaying the charge and discharge states of the electric automobile; and the interface unit is in communication connection with the electric automobile.

11. The three-phase electric vehicle energy interactive control system according to claim 1, wherein the energy conversion module is a bi-directional ACDC circuit and the energy control module is a bi-directional DCDC circuit.

12. A three-phase electric vehicle energy interaction control method, characterized in that the method is applied to the three-phase electric vehicle energy interaction control system according to any one of claims 1 to 11, the method comprising:

13. The method for controlling energy interaction of a three-phase electric vehicle according to claim 12, wherein the step of the control unit adopting a control strategy of a direct current bus voltage and alternating current double closed loop for the energy conversion module in the charging mode comprises:

14. The method for controlling energy interaction of a three-phase electric vehicle according to claim 12, wherein the step of the control unit adopting a voltage closed loop and current closed loop double loop competition control strategy for the energy control module in the charging mode or the grid-connected inversion mode comprises:

15. The method for controlling energy interaction of three-phase electric vehicle according to claim 12, wherein the step of the control unit adopting the integrated control strategy of active power control, reactive power control, fault ride through control, anti-islanding control and PFC bus voltage regulation control for the energy conversion module in the grid-connected inversion mode comprises:

Setting target active power and reactive power;