AU2021445856A1

AU2021445856A1 - Control system and control method for bms power source switch

Info

Publication number: AU2021445856A1
Application number: AU2021445856A
Authority: AU
Inventors: Yiping Chen; Dong Lin; Xiuli SI; Zhijiang YIN; Hongliang YUAN
Original assignee: Alpha Ess Co Ltd
Current assignee: Alpha Ess Co Ltd
Priority date: 2021-05-19
Filing date: 2021-06-25
Publication date: 2023-12-07
Anticipated expiration: 2041-06-25
Also published as: WO2022241906A1; CN113114199A; DE112021007473T5; CN113114199B; AU2021445856B2

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

CONTROL SYSTEM AND CONTROL METHOD FOR BMS POWER SWITCH TECHNICAL FIELD

[0001] The present invention relates to the field of battery control technologies, and in particular, to a control system and control method for a BMS power switch.

BACKGROUNDART

[0002] The battery packs currently used on the market need to be controlled by the BMS control system. The BMS control system is mainly intended to intelligently manage and maintain various battery units, prevent the battery from overcharging and over-discharging, extend the service life of the battery, and monitor the status of the battery.

[0003] The traditional BMS control system's power switch control circuit is implemented by using MOSFET for switching control on the main circuit. It is a design method of high current and high voltage stress. The design is complex and the reliability is low. The main disadvantages are as follows.

[0004] (1) The MOSFET power switch on the main circuit is subject to huge inrush current stress due to the instantaneous charging of the capacitor.

[0005] (2) The MOSFET power switch on the main circuit is subject to the high-voltage switching stress of the main battery circuit.

[0006] (3) The above two disadvantages will bring huge working stress to the MOSFET power switch on the main circuit and shorten the life of the entire BMS control system.

[0007] (4) When the MOSFET power switch on the main circuit is working, 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.

[0008] (5) Using high-power MOSFET has high cost, large expense and poor economic efficiency.

[0009] In order to solve the above defects, the industry usually uses dedicated ASIC (Application Specific Integrated Circuit) to design and implement functions similar to small stress power switching, but its cost is high, its economy is poor, its control logic is complex, and its reliability is low.

SUMMARY OF THE INVENTION

[0010] The technical problem to be solved by the present invention is to provide a control system and control method for a BMS power switch that adopts a minimal stress design and has high reliability and low cost.

[0011] The technical solution adopted by the present invention to solve the technical problem is: a control system for a BMS power switch configured to control a power module to supply power to a BMS control system configured to control an energy storage battery, including a switch module configured to send a turn-on or turn-off signal to the power module and a manual control module for manual control of the switch module, wherein the switch module includes a signal distribution component and a signal adjustment component connected to the signal distribution component, the signal distribution component receives an adjustment signal from the signal adjustment component, distributes the signal and transmits the signal to the power module; and the signal distribution component and the manual control module control changes in the signal input to the power module to turn on or off the power module.

[0012] More specifically, the signal distribution component includes a first resistor and a second resistor connected in series to a first power supply; and two paths are drawn from a point between the first resistor and the second resistor, in which a first path is connected to the power module as an input terminal, and a second path is connected to the signal adjustment component.

[0013] More specifically, the signal adjustment component includes a first triode and a fourth resistor, and a base of the first triode is divided into two paths, in which a first path receives a high-potential signal of the BMS control system through a second diode, and a second path is connected to the ground through the fourth resistor; and a collector of the first triode is grounded, and an emitter of the first triode is connected between the first resistor and the second resistor.

[0014] More specifically, the manual control module includes a third resistor, a manual button and a first diode, and the third resistor, the manual button, the first diode and the fourth resistor are connected in series to the first power supply.

[0015] Further specifically, a manual feedback module for detecting manual operation status is provided on the manual control module, and the manual feedback module detects a manual operation signal and feeds the same back to the BMS control system.

[0016] Further specifically, the manual feedback module includes a second triode, and a base of the second triode is connected to a point between the manual button and the first diode through a fifth resistor and a third diode; a collector of the second triode is divided into two paths, in which a first path is connected to a second power supply through a seventh resistor, and a second path is connected to the BMS control system; and an emitter of the second triode is grounded.

[0017] A control method for the above-mentioned control system for a 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;

[0018] an 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 less than the second judgment threshold; and the manual control module is configured to turn off the signal adjustment component;

[0019] when the output signal is greater than the first judgment threshold, the power module supplies power to the BMS control system; and

[0020] when the output signal is less than the second judgment threshold, the power module stops supplying power to the BMS control system.

[0021] More specifically, the BMS control system outputs a control signal to the signal adjustment component for controlling turn-on and turn-off of the signal adjustment component.

[0022] Further specifically, the manual control module is configured to turn off the signal adjustment component.

[0023] Further specifically, a manual feedback module for detecting manual operation status is provided on the manual control module, and the manual feedback module transmits a detected manual operation signal to the BMS control system;

[0024] when the manual feedback module detects an opening action, the BMS control system sends a turn-off signal to the signal adjustment component; and

[0025] when the manual feedback module detects a closing action, the BMS control system sends a turn-on signal to the signal adjustment component.

[0026] The beneficial effects of the present invention are as follows. 1. The minimum 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. There is no need to adopt additional high-power MOSFET switching elements, thereby avoiding the ground bounce noise caused by switching in the main circuit, and at the same time greatly reducing the complexity of the ground system design and enhancing the reliability of the system. 3. At the same time, high-power MOSFET switching elements and dedicated ASIC (Application Specific Integrated Circuit) are no longer used, so that costs are reduced and the control logic is simple and concise.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a schematic structural diagram of a first embodiment of the present invention;

[0028] FIG. 2 is a schematic structural diagram of a second embodiment of the present invention;

[0029] FIG. 3 is a schematic structural diagram of a third embodiment of the present invention; and

[0030] FIG. 4 is a circuit diagram of the third embodiment of the present invention.

DETAILED DESCRIPTION

[0031] The technical solutions of the present invention are described clearly and completely below in combination with the accompanying drawings. Apparently, the described embodiments are only a part of embodiments of the present invention, rather than all the embodiments. All other embodiments acquired by persons skilled in the art based on the embodiments of the present invention without creative work shall fall within the scope of the present invention.

[0032] In the description of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "central", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are based on the orientation or positional relationships shown in the drawings, are only for the convenience of describing the present invention and simplifying the description rather than indicating or implying that the device or element referred must have a specific orientation and must be constructed and operated in a specific orientation, and thus cannot be construed as limiting the present invention. In addition, the terms "first", "second" and "third" are only for the purpose of description and should not be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that unless otherwise clearly prescribed and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense, and may be for example, fixed connection or detachable connection, integral connection, mechanical connection, electrical connection, direct connection, or indirect connection through an intermediate medium, or internal communication of two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present invention should be understood according to the specific situations. In addition, the technical features in different embodiments of the present invention described below can be combined, so long as there is no conflict between them.

[0034] As shown in FIG. 1, a control system for a BMS power switch is configured to control a power module U1 to supply power to a BMS control system which is configured to control an energy storage battery. The power module U1 may receive power from the energy storage battery and may also be powered by other power sources. The control system includes a switch module for sending a turn-on or turn-off signal to the power module U1 and a manual control module for manual control of 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 an adjustment signal from the signal adjustment component. The signal distribution component distributes the signal and sends the signal to the power module. The signal distribution component and the manual control module control changes in the signal input to the power module U1 to turn on or off the power module Ul.

[0035] Based on the above system, it is necessary to set a first judgment threshold and a second judgment threshold in the power module U1 during control. The first judgment threshold is greater than the second judgment threshold. In the case of being free from other interferences, an initial output signal of the signal distribution component is greater than the first judgment threshold. After the signal adjustment component adjusts the output signal of the signal distribution component, the adjusted output signal is less than the second judgment threshold. The control method of the control system is as follows.

[0036] 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.

[0037] When the output signal of the signal distribution component is less than the second judgment threshold, the signal adjustment module starts to work, and the power module U1 stops supplying power to the BMS control system.

[0038] As shown in FIG. 4, the signal distribution component in the above system includes a first resistor RI and a second resistor R2 connected in series to a first power supply. Two paths are drawn from a point between the first resistor RI and the second resistor R2, in which a first path is connected to the power module U1 as an input terminal PWRBBA, and a second path is connected to the signal adjustment component. The first power supply may be the energy storage battery or other power sources. In the case being free other interference, that is, the signal adjustment component does not work, reasonable distribution of the resistance values of the first resistor RI and the second resistor R2 can enable the voltage of the input terminal PWR_BBA of the first path input to the power module U1 to be greater than the first judgment threshold (the first judgment threshold here is 0.9V), PWRBBA> 0.9V.

[0039] The signal adjustment component includes a first triode Qi and a fourth resistor R4. The first triode Q1 is a PNP transistor. A base of the first triode Q1 is divided into two paths, in which a first path receives a high-potential signal from the BMS control system through a second diode D2, the high-potential signal being sent through an MCU_PWR_HLDHi port of the BMS control system, and a second path is grounded through the fourth resistor R4. A collector of the first triode Qi is grounded. An emitter of the first triode Qi is connected to a point between the first resistor RI and the second resistor R2. The base of the first triode Qi is statically biased to zero potential using the fourth resistor R4. The base-emitter of the first triode Qi is in a forward biased state. The emitter-collector of the first triode Qi is in a conductive state, which can enable that the voltage of the signal distribution component input to the input terminal PWRBBA of the power module U1 is less than the second judgment threshold (the second judgment threshold here is O.4V), PWRBBA <0.4V.

[0040] The manual control module includes a third resistor R3, a manual button Si and a first diode D1. The third resistor R3, the manual button Si, the first diode D Iand the fourth resistor R4 are connected in series to the first power supply. The resistance values of the third resistor R3 and the fourth resistor R4 are reasonably distributed. When a user presses the manual button Si, the first diode D1 is turned on and a cathode voltage of the first diode D1 is between 3-4V. At this time, the base-emitter of the first triode Q1 is in a reverse biased state, the emitter-collector of the first triode Qi is in a cutoff state, the signal adjustment module is turned off and no longer works normally, and the PWRBBA port returns to a state of being greater than 0.9V.

[0041] As shown in FIG. 3, the above system also includes a manual feedback module for detecting manual operation status. The manual feedback module detects a manual operation signal and feeds it back to the BMS control system. The manual feedback module includes a second triode Q2, which is an NPN transistor. A base of the second triode Q2 is connected to a point between the manual button Siand the first diode Di through a fifth resistor R5 and a third diode D3. A collector of the second triode Q2 is divided into two paths, in which a first path is connected to a second power supply through a seventh resistor R7, and a second path is connected to the BMS control system. An emitter of the second triode Q2 is grounded. The second power supply is a 3.3V low-voltage power supply. An IGNSWSTATUS port of the BMS control system receives a signal from the second path to detect whether the manual button Si is pressed. Reasonable distribution 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 Si is pressed. The base-emitter of the second triode Q2 is in a forward biased state. The emitter-collector of the second triode Q2 is in a conductive state. At this time, the collector of the second triode Q2 is at a low potential (O.3V), that is, a low potential logic signal is input to the IGNSWSTATUS port of the BMS control system. When the manual button Siis reset, the first diode Di will be reverse biased to be in a cutoff state, and the third diode D3 is also in a cutoff state. The base emitter of the second triode Q2 is in a zero biased state, and the emitter-collector of the second triode Q2 is in a cutoff state. At this time, the collector of the second triode Q2 is at a high potential (3.3V), that is, a high-level logic signal is input to the IGNSWSTATUS port of the BMS control system.

[0042] From the above recognition mechanism of the working status of the manual button S1, the following logic equation may be derived:

[0043] When the manual button Si is closed, IGNSWSTATUS=O, and

[0044] When the manual button S Iis open, IGNSWSTATUS=1.

[0045] Based on the signal of the above manual feedback module, the signal adjustment component can be controlled through the BMS control system.

[0046] When the manual feedback module detects an opening action, the BMS control system sends a turn-off signal to the signal adjustment component.

[0047] When the manual feedback module detects a closing action, the BMS control system sends a turn-on signal to the signal adjustment component.

[0048] 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 Si is pressed, the signal adjustment component is turned off, and the PWRBBA port voltage returns to a state of being greater than 0.9V. When the manual button Si is released, the signal adjustment component is turned on, and the PWR_BBA port voltage drops to a state of being less than O.4V.

[0049] In this application scheme, the manual button Si is implemented by a self-resetting button. As shown in FIG. 2, the manual button Si will be automatically reset after it is pressed, and the signal adjustment component will be turned on after the automatic reset. At this time, a high potential is input to the signal adjustment component through the BMS control system to continue to ensure that the signal adjustment component is kept in a turn-off state. At the same time, a low potential may also be input to turn on the signal adjustment component, thereby stopping the power module U1 from continuing to supply power to the BMS control system.

[0050] The entire control method in this application scheme is as follows.

[0051] When the BMS control system needs to be turned on, the manual button Si is pressed. The circuit of the third resistor R3, the first diode D1 and the fourth resistor R4 is turned on. The PWRBBA port returns to a state of being greater than 0.9V. The power module U1 starts to supply power to the BMS control system. At this time, the MCUPWRHLDHi port of the BMS control system sends a high potential signal to the base of the first triode Q. Therefore, when the manual button Si is automatically reset, the base of the first triode Qi is still at a high potential. And then the emitter-collector of the first triode Q1 continues to be in a cutoff state. The voltage of the PWRBBA port continues to maintain a state of being greater than 0.9V. The power module U1 continues to maintain a working state to ensure that the BMS control system continues to work.

[0052] When the BMS control system needs to be turned off, the manual button Si is pressed again. Based on the working mechanism of the manual feedback module above, the manual button S Iwill change the circuit of the third resistor R3, the first diode D1 and the fourth resistor R4 from a disconnected state to a conductive state. That is, the logic signal changes from 1 to 0, and it means that the user has pressed the manual button Sl. 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 base of the first triode Q3 through the MCUPWRHLDHi port. At the same time, the manual button Si is automatically reset. At this time, the first triode Qi is turned on. The base emitter of the first triode Q1 is in a forward biased state. The emitter-collector of the first triode Qi is in a conductive state. The PWRBBA port voltage drops to a state less thanO.4V. The power module Ul stops working, and then the BMS control system loses power and stops working.

[0053] Regarding whether the above-mentioned manual button Si 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 Si to force a shutdown or enter other user operation modes.

[0054] In summary, the voltage at the PWRBBA port is greater than 0.9V through the voltage division function between the first resistor RI and the second resistor R2. The voltage at the PWRBBA port is less than O.4V through the cooperation of the first triode Qi and the fourth resistor R4. At the same time, the working state of the first triode Q is disconnected through the manual button Si conducting the circuit of the third resistor R3, the first diode Di and the fourth resistor R4. The working state of the manual button Si is detected through the manual feedback module composed of the third diode D3, the second triode Q2, the fifth resistor R5 and the seventh resistor R7. At the same time, the first triode Qi can be controlled to be turned off and turned on through the BMS control system outputting a high potential or a low potential thereto. 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, thereby avoiding the ground bounce noise caused by switching in the main circuit, and at the same time greatly reducing the complexity of the ground system design and enhancing the reliability of the system. High-power MOSFET switching components and dedicated ASICs (application-specific integrated circuits) are no longer used, so that the costs are reduced and the control logic is simple and concise.

[0055] It should be noted that each resistor in the above circuit does not only refer to a single resistor, it can be composed of a plurality of resistors connected in series, parallel or in series and parallel. For example, the resistance value of the first resistor RI can be realized through two small resistors connected in series. In this application, the use of individual components does not limit the circuit, and other components or component combinations with corresponding functions can also be used alternatively, as long as the overall circuit can achieve the designed effect.

[0056] 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 still fall within the scope of the technical solution of the present invention.

Claims

CLAIMS What is claimed is: 1. A control system for a BMS power switch configured to control a power module to supply power to a BMS control system configured to control an energy storage battery, comprising a switch module configured to send a turn-on or turn-off signal to the power module and a manual control module for manual control of the switch module, wherein the switch module comprises a signal distribution component and a signal adjustment component connected to the signal distribution component, the signal distribution component receives an adjustment signal from the signal adjustment component, distributes the signal and transmits the signal to the power module; and the signal distribution component and the manual control module control changes in the signal input to the power module to turn on or off the power module.
2. The control system for a BMS power switch according to claim 1, wherein the signal distribution component comprises a first resistor and a second resistor connected in series to a first power supply; and two paths are drawn from a point between the first resistor and the second resistor, in which a first path is connected to the power module as an input terminal, and a second path is connected to the signal adjustment component.
3. The control system for a BMS power switch according to claim 2, wherein the signal adjustment component comprises a first triode and a fourth resistor, and a base of the first triode is divided into two paths, in which a first path receives a high-potential signal of the BMS control system through a second diode, and a second path is connected to the ground through the fourth resistor; and a collector of the first triode is grounded, and an emitter of the first triode is connected between the first resistor and the second resistor.
4. The control system for a BMS power switch according to claim 3, wherein the manual control module comprises a third resistor, a manual button and a first diode, and the third resistor, the manual button, the first diode and the fourth resistor are connected in series to the first power

supply.
5. The control system for a BMS power switch according to claim 4, wherein a manual feedback module for detecting manual operation status is provided on the manual control module, and the manual feedback module detects a manual operation signal and feeds the same back to the BMS control system.
6. The control system for a BMS power switch according to claim 5, wherein the manual feedback module comprises a second triode, and a base of the second triode is connected to a point between the manual button and the first diode through a fifth resistor and a third diode; a collector of the second triode is divided into two paths, in which a first path is connected to a second power supply through a seventh resistor, and a second path is connected to the BMS control system; and an emitter of the second triode is grounded.
7. A control method based on the control system for a BMS power switch of 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 second judgment threshold; An 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 less than the second judgment threshold; and the manual control module is configured to turn off the signal adjustment component; when the output signal is greater than the first judgment threshold, the power module supplies power to the BMS control system; and when the output signal is less than the second judgment threshold, the power module stops supplying power to the BMS control system.
8. The control method according to claim 7, wherein the BMS control system outputs a control signal to the signal adjustment component for controlling turn-on and turn-off of the signal adjustment component.
9. The control method according to claim 7, wherein the manual control module is configured to turn off the signal adjustment component.
10. The control method according to claim 8, wherein a manual feedback module for detecting manual operation status is provided on the manual control module, and the manual feedback module transmits a detected manual operation signal to the BMS control system; when the manual feedback module detects an opening action, the BMS control system sends a turn-off signal to the signal adjustment component; and when the manual feedback module detects a closing action, the BMS control system sends a turn-on signal to the signal adjustment component.