CN108365627A - A kind of wind storage isolated network power supply system control method for coordinating based on flexible coordinating factor - Google Patents

Abstract

The invention discloses a coordinated control method for an isolated wind storage grid system based on a flexible coordination factor, and belongs to the technical field of power grid operation and control. Its characteristics include the following steps: ① Obtain the operating parameters of the wind storage isolated grid power supply system; ② establish a coordinated control mechanism for the wind storage isolated grid power supply system; realize the upper coordinated control agent and the lower unit decentralized control agent through direct and indirect actions ③ Calculate the flexible coordination factor of the power balance of the wind storage isolated grid power supply system; ④ The upper layer coordination control agent distributes the flexible coordination factor to the lower energy storage unit decentralized control agent; ⑤ The energy storage inverter implements power control. The coordinated control method of the wind storage isolated grid power supply system based on the flexible coordination factor adopted in the present invention can realize the coordinated control of each unit in the wind storage isolated grid system, and ensure the stability of the output voltage and frequency of the wind storage isolated grid system. The stable operation of the isolated grid storage system provides technical basis and practical methods.

Description

A Coordinated Control Method for Wind Storage Isolated Grid Power Supply System Based on Flexible Coordination Factor

technical field

The invention relates to a coordinated control method for a wind storage isolated grid power supply system, in particular to a coordinated control method for a wind storage isolated grid power supply system based on a flexible coordination factor, and belongs to the technical field of power grid operation and control.

Background technique

Among the distributed energy generation, wind power generation is the project with the most mature technology, the most development conditions and good development prospects. However, limited by the capacity of the large power grid, problems such as "difficulty in grid connection" and "wind abandonment" in the process of large-scale access to the power grid have become major problems restricting the development of wind power. In response to the above-mentioned problems of wind power grid connection, experts at home and abroad have proposed wind-storage combined power generation technology. With the reduction of the cost of energy storage devices and the maturity of technology, wind storage isolated grid power generation technology, as an effective form of wind storage combined power generation technology, can provide a more flexible operation mode for new energy dispersion and small-scale applications, and is gradually being accepted. extensive attention of researchers.

The core technology for the stable operation of the wind storage isolated grid system lies in the coordinated control strategy among the wind turbine output, wind turbine and energy storage inverter, and energy storage charge/discharge conversion. Affected by the natural environment and climate change, the output power of wind power is fluctuating and intermittent. Without the support of a large power grid, the system power and frequency tend to fluctuate in a large range during the isolated operation of wind power, making it difficult to meet the demand of the load. In the wind storage isolated grid system, the access of energy storage units can provide an effective way to solve the problems of power fluctuation and frequency stability in the system caused by wind power fluctuations and load disturbances.

At present, domestic and foreign research on the combined operation of wind storage systems mainly focuses on the grid-connected location, operating costs, stable operation, and control strategies for different fault characteristics, while there are relatively few studies on wind storage isolated grid systems. Some literatures study the operation mode and planning configuration of isolated microgrids such as wind storage, and propose the configuration scheme and typical network topology of isolated microgrids; some literatures apply the control methods of traditional power grids to isolated microgrids, and propose The master-slave control method and peer-to-peer control strategy of the power grid; some research institutions have established experimental systems for isolated micro-grids, and verified the feasibility of the wind storage isolated grid power supply system from multiple perspectives such as physical simulation and computer simulation. But limited to the control method and control strategy, it needs to be further improved to increase the practical level. The core problem of the stable operation of the wind-storage isolated power supply system is: after losing the support of the large power grid, under various external disturbance conditions, the system must rely on its own adjustment ability to restore a stable operating state. In the traditional control method, the power adjustment depends on the large power grid, and the micro-grid itself is not sensitive to changes in external conditions, and its adjustment ability is limited. Under the above-mentioned control mode, the operation of the wind storage system is relatively fragile, and there is a possibility of operation failure under harsh conditions. The application has relatively large limitations, which is not conducive to the commercial operation of the wind storage system, and has poor practicability.

The key to solving the problem is how to track and respond to the AC system's demand for power balance and coordinate control. The complexity of this control lies in that, on the one hand, the control strategy must adapt to changes in various operating conditions, such as energy storage status, fan output changes, system load changes, etc., and different operating conditions require power characteristics provided by energy storage control. It is also different, and its characteristics are also related to the operating state of the wind storage system. On the other hand, how to coordinate and intelligently make decisions about each operating unit in the isolated wind storage grid, and which control mode to adopt to establish a coordinated control mechanism and implement flexible control are also key issues for realizing the stable operation of the wind storage isolated grid system.

Contents of the invention

The purpose of the present invention is to solve the above-mentioned problems existing in the prior art, and to provide a coordinated control method for wind storage isolated grid system based on flexible coordination factors. The coordinated control method adopted in the present invention comprehensively considers various power balance requirements and operating constraints in the wind storage isolated grid system, and can perform coordinated control of the wind storage isolated grid system more effectively and reliably. The stable and coordinated operation of the system provides technical basis and practical methods.

The basic idea of the flexible self-starting method for the wind storage isolated grid system proposed by the present invention is: based on multi-intelligence technology, establish a coordinated control mechanism for the wind storage isolated grid system; comprehensively consider various power balance requirements, and establish a Flexible coordination factor control scheme; based on the above control method, to improve the reliability and practicability of the wind storage isolated grid power supply system.

The technical scheme adopted in the present invention is:

In the isolated power supply system composed of wind turbines and energy storage devices, the balance power of the isolated grid system is dynamically calculated online, and according to the operating conditions of the system, the power control parameters of each operating unit are dynamically adjusted using flexible coordination factors, so as to realize Coordinated control and stable operation of wind storage isolated grid system. It is characterized by the following steps:

Step 1) Obtain the operating parameters of the wind storage isolated grid power supply system;

Step 2) Establish a coordinated control mechanism for the wind storage isolated grid power supply system;

(1) Establish the upper layer coordination control agent of the wind storage isolated grid power supply system;

(2) Establish a distributed control agent for the lower unit of the wind storage isolated grid power supply system;

(3) The interactive behavior between the upper-level coordinated control agent and the lower-level unit decentralized control agent is realized through direct interaction;

(4) The interactive behavior between the distributed control agent of the lower unit and the coordinated control agent of the upper layer is realized through indirect action;

Step 3) Calculate the flexible coordination factor of the power balance of the wind storage isolated grid power supply system;

(1) The upper coordinated control agent samples the active power of the lower unit agent of the wind storage isolated grid system;

(2) The upper-level coordinated control agent calculates the balance power deviation;

(3) Judging whether the balance power deviation is greater than the power coordination control threshold, if the balance power deviation is greater than the power coordination control threshold, proceed to step (4); otherwise go to step (1);

(4) Distribute the balance power deviation to each energy storage unit to obtain the flexible coordination factor;

Step 4) The upper-layer coordinated control agent assigns the flexible coordination factor to the lower-layer energy storage unit decentralized control agent;

Step 5) The energy storage inverter implements power control.

The wind storage isolated grid power supply system refers to an independent AC power supply system composed of wind turbines and energy storage systems.

Obtaining the operating parameters of the wind-storage grid system refers to the active power and reactive power output by the wind turbine, the state of charge of the energy storage system, the load power of the wind-storage grid system, the AC bus voltage, frequency, etc. required parameters.

The establishment of a coordinated control mechanism for the wind-storage isolated grid power supply system refers to the use of multi-agent-based control technology in the wind-storage isolated grid system to coordinate the control of wind power, energy storage power, and load power;

The establishment of the upper-level coordinated control agent of the wind-storage isolated grid power supply system refers to the establishment of an intelligent centralized control module of the wind-storage isolated grid system, which realizes the communication and data collection functions with the decentralized control agent of the lower unit, and according to the system history and current operating status, Carry out analysis and decision-making, and issue coordinated control instructions to the decentralized control agents of the lower unit;

The establishment of a distributed control agent for the lower unit of the wind storage isolated grid power supply system refers to adding an independent intelligent control module to the wind turbine, energy storage unit and load to realize data collection, power control, and coordination with the upper layer of the distributed unit. Communication and other functions;

The calculation of the power balance deviation by the upper-level coordinated control agent refers to the calculation of the power balance deviation according to the following formula:

ΔP＝K _L P _LOAD -K _W P _W -P _B -K _F ΔF

Among them: ΔP represents the balance power difference required for the system to coordinate the active power balance and maintain the system frequency; P _LOAD is the active load power in the wind storage isolated grid power supply system; P _W is the wind storage isolated grid power supply system The active power of the wind turbine; K _L is the load power adjustment parameter, and its value is obtained by the analysis and prediction of the upper-level coordination control agent according to the system historical data and current operating status; K _W is the wind power adjustment parameter, and its value is determined by the upper-level coordination According to the historical data and current operating status of the system, the control agent analyzes and predicts; P _B is the sum of the charging and discharging power of the energy storage unit in the wind storage isolated grid power supply system; ΔF is the system frequency deviation; K _F is the wind storage isolated grid The unit of the power supply system regulates the power.

Distributing the balance power deviation to each energy storage unit to obtain the flexible coordination factor refers to the power allocation according to the following constraints:

Among them: ΔP represents the balance power difference required for the system to coordinate the active power balance and maintain the system frequency; ΔP _i is the power adjustment amount of the i-th energy storage unit in the wind storage isolated grid system, that is, the flexible coordination factor of the distributed power ; P _Bi is the instantaneous power of the i-th energy storage unit; P _Bi ^max is the limit value of the instantaneous charge or discharge power of the i-th energy storage unit.

Compared with prior art, the beneficial effect of the present invention is:

1. The coordinated control method of the wind storage isolated grid power supply system based on the flexible coordination factor can improve the reliability of the system operation. The traditional control method only implements constant frequency and constant voltage control by the energy storage system, which cannot be insensitive to changes in external conditions. There is a lack of coordination among the control units, resulting in large mismatched power and relatively large transient impact during operation. big. The invention reduces the impact of unbalanced power through coordinated control and flexible control factors, and improves the reliability of system operation.

2. The method is easy to implement. This method is based on the original wind storage isolated network control link, establishes a coordinated control finger mechanism and logic, the calculation of the flexible control factor is simple and effective, and the parameters and data of the original control system are maximized, which is easy to implement in terms of control.

3. The method is convenient for commercial development. With the increasing application of the wind storage isolated grid system, the development of the control strategy of the system must have a greater demand, and the present invention has a better prospect for commercial development.

Description of drawings

Figure 1 is a schematic diagram of the wind storage isolated grid system;

Figure 2 is the multi-agent control intention;

Fig. 3 is a schematic diagram of a flow chart of the coordinated control instruction of the wind storage isolated grid system based on the flexible coordination factor;

Fig. 4 is a simulation curve of the active power of the load on the AC bus side of the wind-storage isolated grid system based on the flexible coordination factor.

Fig. 5 is a simulation curve of the AC side frequency of the wind storage isolated grid system based on the flexible coordination factor.

Fig. 6 is a simulation curve diagram of the three-phase current output on the AC load side of the wind-storage isolated grid system based on the flexible coordination factor.

Fig. 7 is a simulation curve diagram of the three-phase voltage output on the AC load side of the wind-storage isolated grid system based on the flexible coordination factor.

Detailed ways

The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and simulation experiments.

As shown in Figure 1-7, a coordinated control method for wind storage isolated grid power supply system based on flexible coordination factors includes the following steps:

Step 1) Obtain the operating parameters of the wind storage isolated grid power supply system;

Step 2) Establish a coordinated control mechanism for the wind storage isolated grid power supply system;

(1) Establish the upper layer coordination control agent of the wind storage isolated grid power supply system;

(2) Establish a distributed control agent for the lower unit of the wind storage isolated grid power supply system;

(3) The interactive behavior between the upper-level coordinated control agent and the lower-level unit decentralized control agent is realized through direct interaction;

(4) The interactive behavior between the distributed control agent of the lower unit and the coordinated control agent of the upper layer is realized through indirect action;

Step 3) Calculate the flexible coordination factor of the power balance of the wind storage isolated grid power supply system;

(1) The upper coordinated control agent samples the active power of the lower unit agent of the wind storage isolated grid system;

(2) The upper-level coordinated control agent calculates the balance power deviation;

(3) Judging whether the balance power deviation is greater than the power coordination control threshold, if the balance power deviation is greater than the power coordination control threshold, proceed to step (4); otherwise go to step (1);

(4) Distribute the balance power deviation to each energy storage unit to obtain the flexible coordination factor;

Step 4) The upper-layer coordinated control agent assigns the flexible coordination factor to the lower-layer energy storage unit decentralized control agent;

Step 5) The energy storage inverter implements power control;

The wind storage isolated grid power supply system refers to an independent AC power supply system composed of wind turbines and energy storage systems.

Obtaining the operating parameters of the wind-storage grid system refers to the active power and reactive power output by the wind turbine, the state of charge of the energy storage system, the load power of the wind-storage grid system, the AC bus voltage, frequency, etc. required parameters.

The establishment of a coordinated control mechanism for the wind-storage isolated grid power supply system refers to the use of multi-agent-based control technology in the wind-storage isolated grid system to coordinate the control of wind power, energy storage power, and load power;

The establishment of the upper-level coordinated control agent of the wind-storage isolated grid power supply system refers to the establishment of an intelligent centralized control module of the wind-storage isolated grid system, which realizes the communication and data collection functions with the decentralized control agent of the lower unit, and according to the system history and current operating status, Carry out analysis and decision-making, and issue coordinated control instructions to the decentralized control agents of the lower unit;

The establishment of a distributed control agent for the lower unit of the wind storage isolated grid power supply system refers to adding an independent intelligent control module to the wind turbine, energy storage unit and load to realize data collection, power control, and coordination with the upper layer of the distributed unit. communication and other functions.

The calculation of the power balance deviation by the upper-level coordinated control agent refers to the calculation of the power balance deviation according to the following formula:

ΔP＝K _L P _LOAD -K _W P _W -P _B -K _F ΔF

Among them: ΔP represents the balance power difference required for the system to coordinate the active power balance and maintain the system frequency; P _LOAD is the active load power in the wind storage isolated grid power supply system; P _W is the wind storage isolated grid power supply system The active power of the wind turbine; K _L is the load power adjustment parameter, and its value is obtained by the analysis and prediction of the upper-level coordination control agent according to the system historical data and current operating status; K _W is the wind power adjustment parameter, and its value is determined by the upper-level coordination According to the historical data and current operating status of the system, the control agent analyzes and predicts; P _B is the sum of the charging and discharging power of the energy storage unit in the wind storage isolated grid power supply system; ΔF is the system frequency deviation; K _F is the wind storage isolated grid The unit of the power supply system regulates the power.

Distributing the balance power deviation to each energy storage unit to obtain the flexible coordination factor refers to the power allocation according to the following constraints:

Among them: ΔP represents the balance power difference required for the system to coordinate the active power balance and maintain the system frequency; ΔP _i is the power adjustment amount of the i-th energy storage unit in the wind storage isolated grid system, that is, the flexible coordination factor of the distributed power ; P _Bi is the instantaneous power of the i-th energy storage unit; P _Bi ^max is the limit value of the instantaneous charge or discharge power of the i-th energy storage unit.

Figure 1 is a schematic diagram of the wind storage isolated grid system. The system composition of the wind storage isolated grid system mainly includes: wind power generation system, energy storage unit and load.

The independent wind storage microgrid system is mainly composed of wind turbines, rectification and inverter control systems, energy storage systems and AC loads; the energy storage system is connected to the AC bus as an energy conversion device, which can store the excess electricity generated by the wind turbines, It can stabilize system power fluctuations and improve power quality, and can also supply power to loads under extreme weather conditions, maintain the stability of system voltage and frequency, and ensure the power supply quality of wind storage isolated grid system to meet the power requirements of loads. However, affected by the randomness and volatility of wind resources and the characteristics of wind turbines themselves, the operation reliability of a single independent wind storage microgrid system is poor. In this case, multiple wind turbines or wind turbines combined with other renewable energy sources can be used in an independent microgrid system to solve the problem of poor operational reliability of a single independent microgrid system.

The schematic diagram of the wind storage isolated grid system is shown in Figure 1. The wind storage isolated grid system is mainly composed of wind power generation system, energy storage unit and load. Compared with doubly-fed wind turbines, direct drive permanent magnet wind turbines save the brushes, slip rings and gearboxes, thereby greatly reducing system maintenance costs and improving system reliability. In this paper, the wind turbines adopt direct drive Permanent magnet wind turbines.

In the wind storage isolated grid system, the direct-drive permanent magnet wind power generation system is mainly composed of wind turbines, direct-drive permanent magnet wind generators, machine-side rectifiers, grid-side inverters and filtering devices; the energy storage unit is mainly composed of batteries, DC It is composed of /DC bidirectional converter, energy storage inverter and filter device. The direct drive permanent magnet wind turbine and energy storage unit supply power to the load through the AC bus.

The working process of the wind storage isolated grid system is as follows: the wind turbine captures the maximum mechanical power from the natural wind, and transmits the generated mechanical power to the generator set through the main shaft, and the electricity generated by the generator set passes through the back-to-back converter control circuit and filter device to the load. Power supply; and the energy storage unit controls the on-off of each bridge arm of the energy storage inverter by collecting the AC bus side voltage and current signals to suppress the fluctuation of wind power output power caused by sudden changes in wind speed. At the same time, the energy storage unit It can also be used as a backup power supply. When the wind power output is too large, the energy storage unit can absorb the excess power generated by the wind power; when the wind power output is too small, the energy storage unit can deliver the stored power to supply power to the load.

Figure 2 is the control intention of multi-agents; "Multi-agents" generally refers to multi-agent systems (or multi-agent technology. Multi-agent systems are an important branch of distributed artificial intelligence, and they are from the end of the 20th century to the beginning of the 21st century. The frontier discipline of artificial intelligence in the world. The purpose of the research is to solve large-scale and complex practical problems, and solving such problems has exceeded the ability of a single agent. A multi-agent system is a collection of multiple agents. Its goal It is to build a large and complex system into a small, inter-communicating and coordinating system that is easy to manage. The research of multi-agents involves the knowledge, goals, skills, planning of agents and how to make agents take coordinated actions to solve problems etc. It mainly studies the interactive communication, coordination and cooperation, and conflict resolution between agents, emphasizing the close group cooperation between multiple agents, rather than the autonomy and exertion of individual abilities, and mainly explains how to analyze, design and integrate multiple agents. Agents form a system that cooperates with each other.

Multi-agent technology is a behavioral feature that realizes the function of the system through the autonomous behavior of each agent and the coordination, control and scheduling between each unit agent. As an important branch of artificial intelligence systems, multi-agent technology has become a key research direction in the future because it can well solve the coordination control and communication problems of control systems. Based on the many advantages of multi-agent technology, applying it to the coordinated control of wind storage isolated grid system can not only solve the communication lag problem existing in traditional coordination algorithms, but also realize the coordinated control of wind storage isolated grid system in layers.

The coordinated control of the wind storage isolated grid system based on multi-agent technology can be realized by two layers of agents: the upper-layer coordinated control agent and the lower-layer unit decentralized control agent. In the wind storage isolated grid system, the decentralized control of the lower unit intelligent body is realized by designing the inverter interface and load port of the wind power generation system and the energy storage unit, and the decentralized control of the lower unit intelligent body is mainly to realize the wind storage isolated grid system Power and voltage output control, system power sampling and AC bus voltage sampling of wind power generation system and energy storage unit. The upper-level coordinated control agent performs related calculations on the active power sampling values and voltage sampling values of the lower-level unit agents of the wind storage isolated grid system at any time, issues action execution commands through the decision-making module and the coordination control command module, and transmits the commands through the communication channel Send to the lower unit for decentralized control of the agent. In the wind storage isolated network system, there is an interaction between the upper coordinated control agent and the lower unit decentralized control agent, and the interaction between the upper coordinated control agent and the lower unit decentralized control agent is realized through direct action , the interaction between the distributed control agent of the lower unit and the coordinated control agent of the upper unit is realized through indirect action. The upper layer coordinates and controls the agent and the lower layer unit decentralizes the interaction process of the agent. In the wind storage isolated grid power supply system based on the flexible coordination factor, the decentralized control agent of the lower unit can realize the perception and interaction between the lower unit and the external environment, and can also realize the control of each unit agent in the wind storage isolated grid system, thus ensuring Stability of output voltage and frequency of wind storage isolated grid system. At the same time, the upper-layer coordinated control agent can realize the judgment of the active power difference of each unit in the distributed control agent of the lower layer unit under the operation and disturbance conditions, and control the command module to issue action execution commands, and the decentralized control agent of the lower layer unit receives After going to the upper layer to coordinate and control the action of the intelligent body to execute the command, the charge and discharge control of the energy storage system is carried out, so as to realize the coordinated operation of the wind storage isolated grid system;

Fig. 3 is a schematic diagram of a flow chart of the coordinated control instruction of the wind storage isolated grid system based on the flexible coordination factor;

After the principle of the wind storage grid system based on multi-agent technology and the interactive response process, how to realize the design of the coordinated control command of the wind storage grid system based on multi-agent technology is the key to ensure the coordinated operation of the wind storage grid system. In the wind-storage isolated grid system, the generation of active power coordinated control commands is mainly determined by the active power balance calculation module, decision-making module, and coordinated control commands of the upper-level coordinated control agent. The wind-storage isolated grid system based on multi-agent technology The generation process of the coordinated control command is as follows: the upper coordinated control agent makes a difference and judges the active power sampling value of the lower unit agent of the wind storage isolated grid system at any time, and gives a bidirectional DC/DC through the decision module and the coordinated control command module The trigger signal control instruction of DC converter charging/discharging; after the decentralized control agent of the lower layer unit receives the action execution command of the upper layer coordination control agent, it controls the charging and discharging of the energy storage system through the negotiation layer and the reaction layer. Specific steps are as follows:

(1) Obtain the operating parameters of the wind storage isolated grid power supply system;

(2) Establish a coordinated control mechanism for the wind storage isolated grid power supply system;

(3) Calculate the flexible coordination factor of the power balance of the wind storage isolated grid power supply system;

1) The upper coordinated control agent samples the active power of the lower unit agent of the wind storage isolated grid system;

2) The upper-layer coordinated control agent calculates the balance power deviation;

3) Judging whether the balance power deviation is greater than the power coordination control threshold, if the balance power deviation is greater than the power coordination control threshold, proceed to step 4); otherwise, go to step 1);

4) Distribute the balance power deviation to each energy storage unit to obtain the flexible coordination factor;

(4) The upper-layer coordinated control agent assigns the flexible coordination factor to the lower-layer energy storage unit decentralized control agent;

(5) The energy storage inverter implements power control;

According to the system block diagram in Figure 1, a wind storage isolated network model composed of wind turbines, energy storage units and loads as the main system is built. The wind power generation system adopts direct-drive permanent magnet wind turbines, because brushes, pulleys and loads can be omitted. Gearbox, etc., can greatly reduce the maintenance cost of the system and improve the reliability of the system.

The wind power generation system in the wind-storage isolated grid system based on the flexible coordination factor mainly adopts the control strategy of back-to-back converters. The back-to-back converters of the wind power generation system mainly include generator-side rectifiers, grid-side It is connected to the grid-side inverter through a DC-side capacitor. The main function of the rectifier on the generator side is to realize the control of the active power of the generator, in order to reduce the power loss of the generator; Voltage control, the grid-side inverter adopts the PQ control strategy of the voltage outer loop and the current inner loop.

The energy storage unit in the wind storage isolated grid system based on the flexible coordination factor is based on the cooperative work of the energy storage inverter and the bidirectional DC/DC converter to realize the coordinated control of the active power of the energy storage unit and maintain the stability of the voltage and frequency of the AC bus side . Among them, the bidirectional DC/DC converter adopts the control strategy of the voltage outer loop and the current inner loop, and the energy storage inverter adopts the droop control mode. The energy storage unit Agent is designed at the interface of the energy storage inverter to realize the output control of the power and voltage of the energy storage unit, system power sampling and voltage sampling.

According to the above-mentioned control strategy and model selection expression, the system simulation model is built on the Matlab/Simulink platform. The basic parameters are set as follows: the rated wind speed is 12m/s, the rated active power output by the fan is 25kW, the initial active power of the load on the AC bus side is 40kW, the reactive power is 0kVar, the initial value of the battery state of charge is 80%, the simulation time for 2s.

In the simulation process, it runs stably in the first 1s, the active power of the load on the AC side is reduced to 30KW at 1s, and the load on the AC bus side returns to the initial active power of 40KW after 1.5s. Before 1s, the system is in a stable running state. In 1s, the load on the AC busbar side decreases to 30KW. At the moment of sudden load change, the frequency fluctuation range decreases, and the output current on the AC load side also decreases. There was a slight oscillation in an instant, but because the reactive power parameter of the model was set to 0, and the multi-agent interaction principle system in the wind storage isolated grid power supply system based on the flexible coordination factor was safe and stable, the output three-phase voltage returned to a stable operating state. After 1.5s, the load on the AC bus side returns to the initial active power of 40KW, the frequency fluctuation range on the AC bus side is consistent with the stable operation state 1s ago, and the output three-phase current on the AC load side returns to the original value. Therefore, it can be concluded that the coordination control method of the wind storage isolated grid power supply system based on the flexible coordination factor in this patent is effective.

Claims (8)

1. A coordinated control method for wind-storage isolated grid power supply system based on flexible coordination factors, which refers to online dynamic calculation of the balance power of the isolated grid system in an isolated power supply system composed of wind turbines and energy storage devices, and according to the Operating conditions, using a flexible coordination factor to dynamically adjust the power control parameters of each operating unit, so as to realize the coordinated control and stable operation of the wind storage isolated grid system; it is characterized in that it includes the following steps: Step 1) Obtain the operating parameters of the wind storage isolated grid power supply system; Step 2) Establish a coordinated control mechanism for the wind storage isolated grid power supply system; (1) Establish the upper layer coordination control agent of the wind storage isolated grid power supply system; (2) Establish a distributed control agent for the lower unit of the wind storage isolated grid power supply system; (3) The interactive behavior between the upper-level coordinated control agent and the lower-level unit decentralized control agent is realized through direct interaction; (4) The interactive behavior between the distributed control agent of the lower unit and the coordinated control agent of the upper layer is realized through indirect action; Step 3) Calculate the flexible coordination factor of the power balance of the wind storage isolated grid power supply system; (1) The upper coordinated control agent samples the active power of the lower unit agent of the wind storage isolated grid system; (2) The upper-level coordinated control agent calculates the balance power deviation; (3) Judging whether the balance power deviation is greater than the power coordination control threshold, if the balance power deviation is greater than the power coordination control threshold, proceed to step (4); otherwise go to step (1); (4) Distribute the balance power deviation to each energy storage unit to obtain the flexible coordination factor; Step 4) The upper-layer coordinated control agent assigns the flexible coordination factor to the lower-layer energy storage unit decentralized control agent; Step 5) The energy storage inverter implements power control. 2. A method for coordinated control of a wind storage isolated grid power supply system based on a flexible coordination factor according to claim 1, characterized in that: in step 1) the wind storage isolated grid power supply system is composed of wind turbines and energy storage systems Independent AC power supply system. 3. A method for coordinated control of wind-storage isolated grid power supply system based on flexible coordination factors according to claim 1, characterized in that: step 1) obtaining the operating parameters of the wind-storage isolated grid system refers to the active power output by the wind turbine , reactive power, state of charge of the energy storage system, load power of the wind storage isolated grid system, AC bus voltage, frequency and other parameters required for grid calculation and control. 4. A method for coordinated control of wind storage isolated grid power supply system based on flexible coordination factors according to claim 1, characterized in that: in step 2), the coordinated control mechanism of wind storage isolated grid power supply system is established. In the isolated grid system, the control technology based on multi-agent is adopted to coordinate the control among wind power, energy storage power and load power. 5. A kind of wind storage isolated network power supply system coordination control method based on flexible coordination factor according to claim 1, it is characterized in that: step 2) establishing the wind storage isolated network power supply system upper coordination control agent refers to the establishment of wind storage The intelligent centralized control module of the isolated network system realizes the communication and data collection functions with the distributed control intelligent body of the lower unit, and analyzes and makes decisions according to the system history and current operating status, and issues the coordinated control instructions to the distributed control intelligent body of the lower unit body. 6. A method for coordinated control of a wind-storage isolated grid power supply system based on flexible coordination factors according to claim 1, characterized in that: establishing the decentralized control agent of the lower unit of the wind-storage isolated grid power supply system refers to the wind power generation unit, An independent intelligent control module is added to the energy storage unit and the load to realize the functions of data collection, power control, and communication with the upper-level coordinated control agent of each distributed unit. 7. A method for coordinated control of a wind-storage isolated grid power supply system based on a flexible coordination factor according to claim 1, wherein the calculation of the power balance deviation by the upper-level coordinated control agent refers to the calculation of the power balance deviation according to the following formula: ΔP＝K _L P _LOAD -K _W P _W -P _B -K _F ΔF Among them: ΔP represents the balance power difference required for the system to coordinate the active power balance and maintain the system frequency; P _LOAD is the active load power in the wind storage isolated grid power supply system; P _W is the wind storage isolated grid power supply system The active power of the wind turbine; K _L is the load power adjustment parameter, and its value is obtained by the analysis and prediction of the upper-level coordination control agent according to the system historical data and current operating status; K _W is the wind power adjustment parameter, and its value is determined by the upper-level coordination According to the historical data and current operating status of the system, the control agent analyzes and predicts; P _B is the sum of the charging and discharging power of the energy storage unit in the wind storage isolated grid power supply system; ΔF is the system frequency deviation; K _F is the wind storage isolated grid The unit of the power supply system regulates the power. 8. The coordinated control method of a wind-storage isolated grid power supply system based on flexible coordination factors according to claim 1, characterized in that: the balance power deviation is distributed to each energy storage unit, and the flexible coordination factor is obtained as follows Constraints for power allocation: Among them: ΔP represents the balance power difference required for the system to coordinate the active power balance and maintain the system frequency; ΔP _i is the power adjustment amount of the i-th energy storage unit in the wind storage isolated grid system, that is, the flexible coordination factor of the distributed power ; P _Bi is the instantaneous power of the i-th energy storage unit; P _Bi ^max is the limit value of the instantaneous charge or discharge power of the i-th energy storage unit.