WO2022241906A1

WO2022241906A1 - Control system and control method for bms power source switch

Info

Publication number: WO2022241906A1
Application number: PCT/CN2021/102259
Authority: WO
Inventors: 陈义平; 司修利; 印志江; 袁宏亮; 林栋�
Original assignee: 沃太能源股份有限公司
Priority date: 2021-05-19
Filing date: 2021-06-25
Publication date: 2022-11-24
Also published as: DE112021007473T5; CN113114199B; AU2021445856B2; AU2021445856A1; CN113114199A

Abstract

A control system and control method for a BMS power source switch. The control system comprises a switch module and a manual control module, wherein the switch module comprises a signal allocation assembly and a signal adjustment assembly. The signal allocation assembly receives an adjusted signal of the signal adjustment assembly, and the signal allocation assembly allocates the signal and transmits the signal into a power source module. The control method comprises: setting a first determination threshold value and a second determination threshold value in a power source module, wherein an initial output signal of a signal allocation assembly is greater than the first determination threshold value, and a signal adjustment assembly adjusts the output signal of the signal allocation assembly to be less than the second determination threshold value; a manual control module being used for shutting down the signal adjustment assembly; when the output signal is greater than the first determination threshold value, the power source module supplying power to a BMS control system; and when the output signal is less than the second determination threshold value, the power source module stopping supplying power to the BMS control system. By using a minimal stress design, the defect of a high-stress design is avoided; and ground bounce noise generated in a main loop switch is avoided.

Description

A control system and control method for a BMS power switch

technical field

The invention relates to the technical field of battery control, in particular to a control system and a control method for a BMS power switch.

Background technique

At present, the battery packs used in the market need to be controlled by the BMS control system. The BMS control system is mainly for intelligent management and maintenance of each battery unit, to prevent the battery from overcharging and overdischarging, to prolong the service life of the battery, and to monitor the state of the battery. .

The traditional BMS control system power switch control circuit is realized by using MOSFET switch control on the main circuit. It belongs to a design method of high current and high voltage stress. The design is complex and the reliability is low. It mainly has the following disadvantages:

①The MOSFET power switch on the main circuit is subjected to the huge inrush current stress caused by the instantaneous charging of the capacitor.

②The MOSFET power switch on the main circuit is subjected to the high voltage switching stress of the main battery circuit.

③The above two points will bring huge working stress to the MOSFET power switch on the main circuit and shorten the life of the entire BMS control system.

④When the MOSFET power switch on the main circuit works, it brings huge ground bounce noise to the digital circuit system, introduces bounce noise to the signal ground of the control system, and reduces the reliability of the signal ground system of the BMS control system.

⑤Using high-power MOSFET, the cost is high, the expense is large, and the economy is poor.

In order to solve the above defects, the industry usually adopts a dedicated ASIC (Application Specific Integrated Circuit) to design and realize a function similar to a small stress power switch, but its cost is high, the economy is poor, the control logic is complicated, and the reliability is low.

Contents of the invention

The technical problem to be solved by the present invention is to provide a control system and a control method of a BMS power switch designed with minimal stress and having high reliability and low cost.

The technical solution adopted by the present invention to solve the technical problem is: a control system of a BMS power switch, which is used to control the power supply module to supply power to the BMS control system, and the BMS control system is used to control the energy storage battery, including The power supply module sends a switch module for opening or closing signals and a manual control module for manually controlling the switch module. The switch module includes a signal distribution component and a signal adjustment component connected to the signal distribution component. The signal distribution component receives The signal adjustment component adjusts the signal, and the signal distribution component distributes the signal and sends the signal to the power module; through the signal distribution component and the manual control module, the signal input to the power module is controlled to turn on or off the power module.

More specifically, the signal distribution component includes a first resistor and a second resistor connected in series to the first power supply; two paths are drawn between the first resistor and the second resistor, and the first path is connected as an input terminal For the power module, the second channel is connected with a signal adjustment component.

More specifically, the signal adjustment component includes a first triode and a fourth resistor, the base of the first triode is divided into two paths, and the first path receives the BMS control system through the second diode. The high-potential signal of the second channel is grounded after passing through the fourth resistor; the collector of the first triode is grounded, and the emitter of the first triode is connected between the first resistor and the second resistor .

More specifically, the manual control module includes a third resistor, a manual button, and a first diode, and the third resistor, manual button, first diode, and fourth resistor are connected in series to the first power supply.

Further specifically, a manual feedback module for detecting a manual operation state is provided on the manual control module, and the manual feedback module detects a manual operation signal and feeds it back to the BMS control system.

Further specifically, the manual feedback module includes a second triode, the base of the second triode is connected between the manual button and the first diode through the fifth resistor and the third diode ; The collector of the second triode is divided into two circuits, the first circuit is connected to the second power supply through the seventh resistor, and the second circuit is connected to the BMS control system; the emitter of the second triode is grounded .

A control method for the control system of the above-mentioned BMS power switch, wherein a first judgment threshold and a second judgment threshold are set inside the power module, and the first judgment threshold is greater than the second judgment threshold;

The initial output signal of the signal distribution component is greater than the first judgment threshold, and the signal adjustment component adjusts the output signal of the signal distribution component to be smaller than the second judgment threshold; the manual control module is used to close the signal adjustment component;

When the output signal is greater than the first judgment threshold, the power supply module supplies power to the BMS control system;

When the output signal is smaller than the second judgment threshold, the power module stops supplying power to the BMS control system.

Further specifically, the BMS control system outputs a control signal to the signal adjustment component for controlling the opening and closing of the signal adjustment component.

Further specifically, the manual control module is used to close the signal adjustment component.

Further specifically, a manual feedback module for detecting the manual operation state is provided on the manual control module, and the manual feedback module sends the detected manual operation signal to the BMS control system;

When the manual feedback module detects the opening action, the BMS control system sends a closing signal to the signal adjustment component;

When the manual feedback module detects a closing action, the BMS control system sends an opening signal to the signal adjustment component.

The beneficial effects of the present invention are: 1. The minimal stress design technology is adopted in the design, the high reliability design method of the small signal system is fully utilized, and the disadvantages of the high stress design technology are perfectly avoided; 2. It is not necessary to use additional The high-power MOSFET switching element avoids the ground bounce noise caused by switching in the main circuit, and at the same time greatly reduces the complexity of the ground system design and enhances the reliability of the system; 3. At the same time, no longer use high-power MOSFET switching elements and dedicated ASIC (Application Specific Integrated Circuit), reduces cost, and the control logic is simple and concise.

Description of drawings

Fig. 1 is the structural representation of first kind of embodiment of the present invention;

Fig. 2 is the structural representation of the second embodiment of the present invention;

Fig. 3 is the structural representation of the third embodiment of the present invention;

Fig. 4 is a circuit diagram of a third embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, or in a specific orientation. construction and operation, therefore, should not be construed as limiting the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations. In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

As shown in Figure 1, a control system of a BMS power switch is used to control the power supply module U1 to supply power to the BMS control system, the BMS control system is used to control the energy storage battery, and the power supply module U1 can receive the energy storage battery Power supply can also be powered by other power sources. The control system includes a switch module for sending an on or off signal to the power supply module U1 and a manual control module for manually controlling the switch module. The switch module includes a signal distribution component and The signal adjustment component connected to the signal distribution component, the signal distribution component receives the adjustment signal of the signal adjustment component, the signal distribution component distributes the signal and sends the signal to the power module; through the signal distribution component and the manual control module Controlling the change of the signal input to the power module U1 enables the power module U1 to be turned on or off.

Based on the above system, it is necessary to set the first judgment threshold and the second judgment threshold in the power supply module U1 during control, wherein the first judgment threshold is greater than the second judgment threshold, and the signal distribution component is free from other interferences, and its initial output The signal is greater than the first judgment threshold; and when the signal adjustment component adjusts the output signal of the signal distribution component, the adjusted output signal is smaller than the second judgment threshold, and the control method of the control system is as follows:

When the output signal of the signal distribution component (the input signal received by the power module U1) is greater than the first judgment threshold, the signal adjustment component does not work at this time, and the power module U1 supplies power to the BMS control system.

When the output signal of the signal distribution component is smaller than the second judgment threshold, the signal adjustment module starts to work at this time, and the power supply module U1 stops supplying power to the BMS control system.

Wherein, as shown in FIG. 4, the signal distribution component in the above system includes a first resistor R1 and a second resistor R2 connected in series on the first power supply, and two resistors are drawn between the first resistor R1 and the second resistor R2. The first path is connected to the power module U1 as the input terminal PWR_BBA, and the second path is connected to the signal adjustment component; the first power supply can be an energy storage battery or other power sources, and the first resistor R1 and the second resistor R2 are reasonably distributed. Resistance value, in the absence of other interference, that is, the signal adjustment component does not work, so that the voltage of the input terminal PWR_BBA of the first channel input to the power module U1 is greater than the first judgment threshold (here the first judgment threshold is 0.9V), PWR_BBA> 0.9V.

The signal adjustment component includes a first triode Q1 and a fourth resistor R4, the first triode Q1 is a PNP transistor, the base of the first triode Q1 is divided into two paths, the first path passes through the second two Diode D2 receives the high-potential signal of the BMS control system, the high-potential signal is sent through the port of MCU_PWR_HLD_Hi of the BMS control system, and the second channel is grounded after passing through the fourth resistor R4; the collector of the first triode Q1 Grounded, the emitter of the first triode Q1 is connected between the first resistor R1 and the second resistor R2. The base of the first triode Q1 is statically biased at zero potential by the fourth resistor R4, the base-emitter of the first triode Q1 is in a forward biased state, and the emitter of the first triode Q1 - The collector is in the conducting state, which means that the voltage of the input terminal PWR_BBA input from the signal distribution component to the power module U1 is lower than the second judgment threshold (here the second judgment threshold is 0.4V), and PWR_BBA<0.4V.

The manual control module includes a third resistor R3, a manual button S1 and a first diode D1, and the third resistor R3, manual button S1, first diode D1 and fourth resistor R4 are connected in series on the first power supply, Reasonably distribute the resistance values of the third resistor R3 and the fourth resistor R4; when the user presses the manual button S1, the first diode D1 is turned on and the cathode voltage of the first diode D1 is between 3-4V, At this time, the base-emitter of the first triode Q1 is in the reverse biased state, the emitter-collector of the first triode Q1 is in the cut-off state, the signal adjustment module is turned off and no longer works normally, the PWR_BBA port return to a state greater than 0.9V.

As shown in Figure 3, the above-mentioned system also includes a manual feedback module for detecting the manual operation state, and the manual feedback module detects that the manual operation signal is fed back to the BMS control system; the manual feedback module includes a second triode Q2, the The second triode Q2 is an NPN transistor, and the base of the second triode Q2 is connected between the manual button S1 and the first diode D1 through the fifth resistor R5 and the third diode D3; The collector of the second transistor Q2 is divided into two circuits, the first circuit is connected to the second power supply through the seventh resistor R7, and the second circuit is connected to the BMS control system; the emitter of the second transistor Q2 Grounding; Wherein, the second power supply is a low-voltage power supply of 3.3V. The IGN_SW_STATUS port of the BMS control system receives the signal from the second channel to detect whether the manual button S1 is pressed. Reasonable allocation of the resistance values of the fifth resistor R5 and the seventh resistor R7 can make the third diode D3 conduct when the manual button S1 is pressed, and the base-emitter of the second transistor Q2 is in forward bias state, the emitter-collector of the second transistor Q2 is in the conduction state, and the collector of the second transistor Q2 is at a low potential (≈0.3V), that is, input a Low potential logic signal; and when the manual button S1 is reset, the first diode D1 will be reverse biased in the off state, and the third diode D3 is also in the off state, and the base of the second transistor Q2- The emitter is in the zero bias state, and the emitter-collector of the second transistor Q2 is in the cut-off state. At this time, the collector of the second transistor Q2 is at a high potential (≈3.3V), that is, to the BMS control system. The IGN_SW_STATUS port inputs a logic high signal.

From the identification mechanism of the working state of the manual button S1 above, the following logic equation can be obtained:

When the manual button S1 is closed, IGN_SW_STATUS=0,

When the manual button S1 is open, IGN_SW_STATUS=1.

Based on the signal of the above-mentioned manual feedback module, the control of the signal adjustment component can be realized through the BMS control system,

In the above control method for the BMS power switch, the signal adjustment component can be turned off and on through the manual button S1, that is, when the manual button S1 is pressed, the signal adjustment component is turned off, and the PWR_BBA port voltage returns to a value greater than 0.9V. state, and when the manual button S1 is disconnected, the signal adjustment component is turned on, and the voltage of the PWR_BBA port drops to a state less than 0.4V.

In this application scheme, the manual button S1 adopts a self-resetting button. As shown in Figure 2, it will automatically reset after the manual button S1 is pressed, and the signal adjustment component will be turned on after the automatic reset. The adjustment component inputs a high potential to continue to ensure that the signal adjustment component is turned off; at the same time, it can also input a low potential to turn on the signal adjustment component, thereby stopping the power module U1 from continuing to supply power to the BMS control system.

The entire control method in this application scheme is as follows:

When the BMS control system needs to be turned on, press the manual button S1, the circuit of the third resistor R3, the first diode D1 and the fourth resistor R4 is turned on, the PWR_BBA port returns to a state greater than 0.9V, and the power module U1 starts to The BMS control system supplies power. At this time, the MCU_PWR_HLD_Hi port of the BMS control system sends a high potential signal to the base of the first triode Q1, so when the manual button S1 is automatically reset, the base of the first triode Q1 is still at high Potential, and then can continue to keep the emitter-collector of the first transistor Q1 in the cut-off state, the voltage of the PWR_BBA port continues to maintain a state greater than 0.9V, and the power module U1 continues to maintain a working state to ensure that the BMS control system continues to work.

When the BMS control system needs to be turned off, press the manual button S1 again. Based on the working mechanism of the manual feedback module above, the manual button S1 will switch the circuit of the third resistor R3, the first diode D1 and the fourth resistor R4 from the disconnected state To the change of the conduction state, that is, the logic signal changes from 1 to 0, it means that the user has pressed the manual button S1. At this time, it means that the user wants to turn off the BMS control system. The BMS control system sends a low potential signal to the first three through the MCU_PWR_HLD_Hi port At the base of the transistor Q3, at the same time the manual button S1 automatically resets, at this time the first triode Q1 is turned on, the base-emitter of the first triode Q1 is in a forward biased state, the first triode The emitter-collector of Q1 is in the conduction state, the PWR_BBA port voltage drops to less than 0.4V, the power module U1 stops working, and then the BMS control system loses power and stops working.

Whether the above-mentioned manual button S1 is pressed or not, user behavior can be defined through software design to control the working mode of the device. User behavior can be freely defined through software and matched with the working mode of the device. For example, when the system is working, the user presses the manual button S1 to force shutdown, or enters into other user operation modes.

In summary, the voltage at the PWR_BBA port is greater than 0.9V through the voltage division function between the first resistor R1 and the second resistor R2, and the voltage at the PWR_BBA port is less than 0.4V through the cooperation of the first transistor Q1 and the fourth resistor R4. V, while turning on the third resistor R3, the first diode D1, and the fourth resistor R4 through the manual button S1 to turn off the working state of the first triode Q1; through the third diode D3, The manual feedback module composed of the second transistor Q2, the fifth resistor R5 and the seventh resistor R7 detects the working state of the manual button S1, and at the same time can output high potential or low potential to the first transistor Q1 through the BMS control system to control It is turned off and turned on; the overall circuit adopts the design idea of minimal stress, makes full use of the high reliability design method of the small signal system, and perfectly avoids the disadvantages of high stress design technology; at the same time, there is no need to use additional high-power MOSFET switches components, avoiding the ground bounce noise caused by switching in the main circuit, and greatly reducing the complexity of the ground system design, enhancing the reliability of the system; no longer using high-power MOSFET switching components and special ASICs (application-specific integrated circuits), reducing The cost and control logic are simple and concise.

It should be noted that each resistor in the above circuit does not only refer to a single resistor, it can be composed of multiple resistors connected in series, parallel or in series and parallel. For example, the resistance value of the first resistor R1 can be connected in series through two small resistors. made. In this application, the use of each component does not limit the circuit, and other components or component combinations with corresponding functions can also be replaced, so that the overall circuit can achieve the designed effect.

It should be emphasized that: the above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are valid. Still belong to the scope of the technical solution of the present invention.

Claims

A control system of a BMS power switch, used to control a power module to supply power to the BMS control system, the BMS control system is used to control an energy storage battery, and is characterized in that it includes a switch for sending an on or off signal to the power module module and a manual control module for manually controlling the switch module, the switch module includes a signal distribution component and a signal adjustment component connected to the signal distribution component, the signal distribution component receives the adjustment signal of the signal adjustment component, and the signal distribution The component distributes the signal and sends the signal to the power module; through the signal distribution component and the manual control module, the signal input to the power module is controlled to turn on or off the power module.
The control system of the BMS power switch according to claim 1, wherein the signal distribution component includes a first resistor and a second resistor connected in series on the first power supply; between the first resistor and the second resistor Two paths are drawn between the resistors, the first path is connected to the power module as an input terminal, and the second path is connected to a signal adjustment component.
The control system of the BMS power switch according to claim 2, wherein the signal adjustment component includes a first triode and a fourth resistor, and the base of the first triode is divided into two circuits , the first path receives the high-potential signal of the BMS control system through the second diode, and the second path passes through the fourth resistor and then grounds; the collector of the first triode is grounded, and the first triode The emitter is connected between the first resistor and the second resistor.
The control system of the BMS power switch according to claim 3, wherein the manual control module includes a third resistor, a manual button and a first diode, and the third resistor, the manual button, the first The diode and the fourth resistor are connected in series with the first power supply.
The control system of the BMS power switch according to claim 4, wherein a manual feedback module for detecting the manual operation state is set on the manual control module, and the manual feedback module detects that the manual operation signal is fed back To the BMS control system.
The control system of the BMS power switch according to claim 5, wherein the manual feedback module includes a second triode, and the base of the second triode passes through the fifth resistor, the third two The pole tube is connected between the manual button and the first diode; the collector of the second triode is divided into two paths, the first path is connected to the second power supply through the seventh resistor, and the second path is connected to the BMS control system; the emitter of the second triode is grounded.
A control method based on the control system of the BMS power switch according to claim 1, wherein a first judgment threshold and a second judgment threshold are set inside the power module, and the first judgment threshold is greater than the first judgment threshold Two judgment thresholds;

The initial output signal of the signal distribution component is greater than the first judgment threshold, and the signal adjustment component adjusts the output signal of the signal distribution component to be smaller than the second judgment threshold; the manual control module is used to close the signal adjustment component;

When the output signal is greater than the first judgment threshold, the power supply module supplies power to the BMS control system;

When the output signal is smaller than the second judgment threshold, the power module stops supplying power to the BMS control system.
The control method according to claim 7, wherein the BMS control system outputs a control signal to the signal adjustment component for controlling the opening and closing of the signal adjustment component.
The control method according to claim 7, wherein the manual control module is used to close the signal adjustment component.
The control method according to claim 8, characterized in that a manual feedback module for detecting the manual operation state is set on the manual control module, and the manual feedback module sends the detected manual operation signal to the BMS control system;

When the manual feedback module detects the opening action, the BMS control system sends a closing signal to the signal adjustment component;

When the manual feedback module detects a closing action, the BMS control system sends an opening signal to the signal adjustment component.