Delay shutdown circuit and battery management system

Abstract

The utility model relates to a time-delay shutdown circuit and a battery management system. The time-delay shutdown circuit comprises an enabling circuit which is used for switching on or switching off according to a received enabling control signal; the delay circuit is connected with the enable circuit and is used for outputting a first power supply control signal according to the received power supply signal under the condition that the enable circuit is switched on, and outputting a second power supply control signal after delaying shutdown time based on the received power supply signal under the condition that the enable circuit is switched off, the second power supply control signal is different from the first power supply control signal; and the power supply circuit is connected with the time delay circuit and used for controlling the battery module to supply power according to the first power supply control signal and controlling the battery module to stop supplying power according to the second power supply control signal. Therefore, when the battery module or the main control chip of the BMS control panel is in an abnormal working state, it is ensured that the battery module continuously supplies power to the main control chip within the delayed shutdown time, so that it is ensured that the main control chip completes fault recording or resetting.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage battery systems, and in particular to a delayed shutdown circuit and a battery management system. Background Art

[0002] In household energy storage battery systems, the power supply for the BMS (Battery Management System) control board usually comes from the battery module.

[0003] When the battery module is in an abnormal working state, the power supply of the BMS control board needs to be cut off in time to ensure that the BMS control board and the battery module will not be damaged. In order to record the fault information of the battery module, the main control chip of the BMS control board needs to continue to work for a period of time after the fault occurs to complete the fault recording. During this period, the main control chip needs to be kept powered on. In addition, when the main control chip of the BMS control board is in an abnormal working state, a certain reset time needs to be given to the main control chip. During this period, the main control chip needs to be kept powered on.

[0004] In the related art, the delayed shutdown circuit used in the energy storage battery system mostly adopts the supercapacitor solution, that is, adding several supercapacitors to the power supply circuit of the main control chip. When the power supply of the main control chip disappears, the supercapacitor is used to discharge, so that the main control chip continues to work for a period of time after the power is cut off. However, the supercapacitor solution has the following problems: (1) The BMS control board components are highly integrated, while the supercapacitor components are large in size, which poses certain challenges to the hardware device layout and structural design; (2) The power supply of the main control chip is usually provided by the DC-DC / LDO power conversion chip, which has certain requirements on the capacitive load capacity of the power conversion chip, which limits the selection of the power conversion chip to a certain extent; (3) When a large capacitor is connected to the output side of the power supply, when the downstream load is large, it is easy to trigger the overcurrent protection of the power conversion chip during the startup process, resulting in the failure of the entire energy storage battery system to operate normally. Utility Model Content

[0005] Based on this, it is necessary to provide a delayed shutdown circuit and a battery management system to address the above technical problems.

[0006] In a first aspect, the present application provides a delayed shutdown circuit, comprising:

[0007] An enabling circuit, used to turn on or off according to a received enabling control signal;

[0008] a delay circuit connected to the enabling circuit, configured to output a first power supply control signal according to a received power supply signal when the enabling circuit is turned on, and to output a second power supply control signal after a delayed shutdown time based on the received power supply signal when the enabling circuit is turned off, wherein the second power supply control signal is different from the first power supply control signal;

[0009] A power supply circuit is connected to the delay circuit and is used to control the battery module to supply power according to the first power supply control signal, and to control the battery module to stop supplying power according to the second power supply control signal.

[0010] In one embodiment, the delay circuit comprises:

[0011] a delay subcircuit connected to the enabling circuit, configured to output a first voltage signal and a second voltage signal according to a received power signal when the enabling circuit is turned on, and to output a third voltage signal and a fourth voltage signal after a delayed shutdown time based on the received power signal when the enabling circuit is turned off;

[0012] A comparison subcircuit is respectively connected to the delay subcircuit and the power supply circuit, and is used to output the first power supply control signal according to the first voltage signal and the second voltage signal, and to output the second power supply control signal according to the third voltage signal and the fourth voltage signal.

[0013] In one embodiment, the delay subcircuit includes a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor;

[0014] The first end of the first resistor is used to receive a power signal, and the second end of the first resistor is connected to the enabling circuit;

[0015] The first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the comparison subcircuit;

[0016] The first end of the third resistor is connected to the first end of the first resistor, and the second end of the third resistor is connected to the comparison subcircuit;

[0017] The first end of the fourth resistor is connected to the second end of the third resistor, and the second end of the fourth resistor is grounded;

[0018] The first end of the first capacitor is connected to the second end of the second resistor, and the second end of the first capacitor is grounded;

[0019] The length of the delayed shutdown time is determined by the resistance values ​​of the first resistor, the second resistor, the third resistor and the fourth resistor and the capacity of the first capacitor.

[0020] In one of the embodiments, the comparison subcircuit includes a fifth resistor and a first comparator;

[0021] A first end of the fifth resistor is connected to the delay sub-circuit, and a second end of the fifth resistor is connected to the output end of the first comparator;

[0022] The first input terminal of the first comparator is connected to the delay sub-circuit, and the second input terminal of the first comparator is connected to the delay sub-circuit.

[0023] In one embodiment, the power supply circuit comprises:

[0024] an optical coupler circuit, connected to the delay circuit and the first electrode of the battery module respectively, and configured to output a power-on signal according to the first power supply control signal, and output a power-off signal according to the second power supply control signal;

[0025] The transformer subcircuit is respectively connected to the optocoupler subcircuit and the second pole of the battery module, and is used to connect the load, wherein the transformer subcircuit is used to draw power from the battery module according to the power-drawing signal to supply power to the load, and to stop drawing power from the battery module according to the power-off signal to stop supplying power to the load.

[0026] In one of the embodiments, the optocoupler subcircuit includes a sixth resistor and a first optocoupler isolator;

[0027] The first end of the sixth resistor is connected to the delay circuit, and the second end of the sixth resistor is connected to the first input end of the first optical coupler isolator;

[0028] The first output end of the first optocoupler isolator is grounded, the second input end of the first optocoupler isolator is connected to the transformer subcircuit, and the second output end of the first optocoupler isolator is connected to the first pole of the battery module.

[0029] In one embodiment, the voltage transformation subcircuit includes a seventh resistor, an eighth resistor, a ninth resistor, a first transistor, a first diode, and a first transformer;

[0030] The first end of the seventh resistor is connected to the second pole of the battery module, the second end of the seventh resistor is connected to the first end of the eighth resistor, the second end of the eighth resistor is connected to the optocoupler circuit, the first end of the ninth resistor is connected to the first end of the eighth resistor, the second end of the ninth resistor is connected to the control end of the first transistor, the first end of the first transistor is connected to the first end of the seventh resistor, the second end of the first transistor is connected to the first end of the first diode, the second end of the first diode is connected to the primary side of the first transformer, and the secondary side of the first transformer is used to connect a load.

[0031] In one embodiment, the enabling circuit includes a tenth resistor, an eleventh resistor and a first transistor;

[0032] The first end of the tenth resistor is used to receive the enable control signal, and the second end of the tenth resistor is connected to the control end of the first transistor;

[0033] The first end of the eleventh resistor is connected to the control end of the first transistor, and the second end of the eleventh resistor is connected to the first end of the first transistor;

[0034] The first end of the first transistor is grounded, and the second end of the first transistor is connected to the delay circuit.

[0035] In one embodiment, the enabling circuit is used to be turned on when the enabling control signal is a first level signal, and turned off when the enabling control signal is a second level signal, the second level signal is different from the first level signal, and the delayed shutdown circuit further includes:

[0036] A backup circuit, wherein the input end of the backup circuit is used to receive the enable control signal, the output end of the backup circuit is connected to the power supply circuit, and the backup circuit is used to generate the first power supply control signal according to the first level signal to control the power supply of the battery module when the enable circuit is abnormal.

[0037] In a second aspect, the present application also provides a battery management system, comprising the delayed shutdown circuit described in any of the above embodiments.

[0038] The above-mentioned delayed shutdown circuit and battery management system include an enabling circuit, a delay circuit and a power supply circuit. The enabling circuit is turned on or off according to the received enabling control signal; the delay circuit is connected to the enabling circuit, and when the enabling circuit is turned on, the delay circuit outputs a first power supply control signal according to the received power supply signal, and when the enabling circuit is turned off, the delay circuit outputs a second power supply control signal after the delayed shutdown time based on the received power supply signal; the power supply circuit is connected to the delay circuit, and the power supply circuit controls the power supply of the battery module according to the first power supply control signal, for example, controls the battery module to supply power to the main control chip of the battery management system, and controls the battery module to stop supplying power according to the second power supply control signal, for example, controls the battery module to stop supplying power to the main control chip; the embodiment of the present application thus realizes a delayed shutdown circuit, and when the main control chip of the battery module or the BMS control board is in an abnormal working state, the delayed shutdown circuit ensures that the battery module continues to supply power to the main control chip during the delayed shutdown time, so as to ensure that the main control chip completes fault recording or reset. The delayed shutdown circuit provided in the embodiment of the present application does not involve a supercapacitor. The delayed shutdown circuit has a simple structure, a small size, a low cost, and is easy to implement. The delayed shutdown circuit will not limit the selection of the power conversion chip, and the operation of the delayed shutdown circuit will not trigger the overcurrent protection of the power conversion chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a structural block diagram of a delayed shutdown circuit in one embodiment;

[0040] Figure 2 is a schematic diagram of the structure of an enabling circuit and a delay circuit in one embodiment;

[0041] Figure 3 is a schematic diagram of the structure of a power supply circuit in one embodiment;

[0042] Figure 4 FIG. 4 is a schematic diagram of the structure of a delayed shutdown circuit in an embodiment. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] The delayed shutdown circuit provided in the embodiment of the present application can be applied to an energy storage battery system; illustratively, it can be applied to a main control chip or other components of a battery management system (BMS) in the energy storage battery system, or to components of other boards, power boards or control boards in the energy storage battery system.

[0045] In one embodiment, Figure 1 As shown, the delayed shutdown circuit includes an enabling circuit 100 , a delay circuit 200 and a power supply circuit 300 .

[0046] The enabling circuit 100 is used to turn on or off according to the received enabling control signal POWER_CTRL. The enabling circuit 100 is used to turn on when the received enabling control signal POWER_CTRL is a first level signal, and to turn off when the enabling control signal POWER_CTRL is a second level signal, and the second level signal is different from the first level signal; for example, the first level signal is a high level signal, and the second level signal is a low level signal. The energy storage battery system includes a battery module; the main control chip may output a first level signal after the battery module is turned on; the main control chip may output a second level signal when the battery module or the main control chip is in an abnormal working state.

[0047] The delay circuit 200 is connected to the enabling circuit 100. The delay circuit 200 is used to output a first power supply control signal according to the received power supply signal when the enabling circuit 100 is turned on, and to output a second power supply control signal after a delayed shutdown time based on the received power supply signal when the enabling circuit 100 is turned off. The second power supply control signal is different from the first power supply control signal. Exemplarily, the power supply signal can be 3.3V; the power supply control signal can be represented by POWER_SW. The power supply circuit 300 is connected to the delay circuit 200. The power supply circuit 300 is used to control the power supply of the battery module according to the first power supply control signal, and to control the battery module to stop supplying power according to the second power supply control signal.

[0048] Among them, after the battery module is turned on, the enabling circuit 100 will be turned on, the delay circuit 200 will directly output the first power supply control signal according to the power supply signal, and the delay circuit 200 will not delay the shutdown time, so that the power supply circuit 300 controls the battery module to supply power normally, for example, controls the battery module to supply power to the main control chip normally. When the battery module or the main control chip is in an abnormal working state, the enabling circuit 100 will be turned off, and the delay circuit 200 will output the second power supply control signal after the delay shutdown time based on the power supply signal, and the power supply circuit 300 controls the battery module to stop supplying power according to the second power supply control signal. The delay circuit 200 ensures that when the battery module or the main control chip is in an abnormal working state, the battery module continues to supply power within the delayed shutdown time, and the main control chip can use the delayed shutdown time to complete fault recording or reset.

[0049] The delayed shutdown circuit provided in the embodiment of the present application does not involve a supercapacitor. The delayed shutdown circuit has a simple structure, a small size, a low cost, and is easy to implement. The delayed shutdown circuit will not limit the selection of the power conversion chip, and the operation of the delayed shutdown circuit will not trigger the overcurrent protection of the power conversion chip.

[0050] In one embodiment, reference Figure 2 The delay circuit 200 includes a delay sub-circuit 210 and a comparison sub-circuit 220 .

[0051] The delay sub-circuit 210 is connected to the enabling circuit 100. The delay sub-circuit 210 is used to output a first voltage signal and a second voltage signal according to a received power supply signal when the enabling circuit 100 is turned on, and to output a third voltage signal and a fourth voltage signal after a delayed shutdown time based on the received power supply signal when the enabling circuit 100 is turned off.

[0052] Among them, after the battery module is turned on, the enabling circuit 100 will be turned on, the delay subcircuit 210 directly outputs the first voltage signal and the second voltage signal according to the power signal, and the delay subcircuit 210 does not delay the shutdown time, so that the power supply circuit 300 controls the battery module to supply power normally, for example, controls the battery module to supply power to the main control chip normally. When the battery module or the main control chip is in an abnormal working state, the enabling circuit 100 will be turned off, and the delay subcircuit 210 will output the third voltage signal and the fourth voltage signal after the delay shutdown time based on the power signal, and the power supply circuit 300 controls the battery module to stop supplying power according to the second power supply control signal.

[0053] The comparison subcircuit 220 is connected to the delay subcircuit 210 and the power supply circuit 300 respectively, and is used to output a first power supply control signal according to the first voltage signal and the second voltage signal, and to output a second power supply control signal according to the third voltage signal and the fourth voltage signal.

[0054] Among them, the comparison sub-circuit 220 can output a first power supply control signal by comparing the first voltage signal with the second voltage signal, and the first power supply control signal can be a high-level signal; the comparison sub-circuit 220 can output a second power supply control signal by comparing the third voltage signal with the fourth voltage signal, and the second power supply control signal can be a low-level signal.

[0055] In this embodiment, the delay circuit 200 includes a delay sub-circuit 210 and a comparison sub-circuit 220, so that the delay circuit 200 has a simple structure, a small volume, a low cost, and is easy to implement.

[0056] In one embodiment, continue to refer to Figure 2 The delay sub-circuit 210 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a first capacitor C1.

[0057] The first end of the first resistor R1 is used to receive the power signal, and the second end of the first resistor R1 is connected to the enabling circuit 100; the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is connected to the comparison subcircuit 220; the first end of the third resistor R3 is connected to the first end of the first resistor R1, and the second end of the third resistor R3 is connected to the comparison subcircuit 220; the first end of the fourth resistor R4 is connected to the second end of the third resistor R3, and the second end of the fourth resistor R4 is grounded; the first end of the first capacitor C1 is connected to the second end of the second resistor R2, and the second end of the first capacitor C1 is grounded;

[0058] The length of the delayed shutdown time is determined by the resistance values ​​of the first resistor R1 , the second resistor R2 , the third resistor R3 , and the fourth resistor R4 and the capacity of the first capacitor C1 .

[0059] The third resistor R3 and the fourth resistor R4 form a voltage divider circuit. When the enabling circuit 100 is turned on, the second end of the third resistor R3 is used to output the first voltage signal, and the second end of the second resistor R2 is used to output the second voltage signal; when the enabling circuit 100 is turned off, the power signal charges the first capacitor C1 through the first resistor R1 and the second resistor R2, the second end of the third resistor R3 is used to output the third voltage signal, and the second end of the second resistor R2 is used to output the fourth voltage signal.

[0060] In this embodiment, the delay subcircuit 210 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a first capacitor C1, so that the delay subcircuit 210 has a simple structure, a small volume, a low cost and is easy to implement. The delay shutdown time can be adjusted by adjusting the resistance value of at least one of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 or adjusting the capacity of the first capacitor C1.

[0061] In one embodiment, continue to refer to Figure 2 , the comparison sub-circuit 220 includes a fifth resistor R5 and a first comparator U1.

[0062] The first end of the fifth resistor R5 is connected to the delay sub-circuit 210 , and the second end of the fifth resistor R5 is connected to the output end of the first comparator U1 ; the first input end of the first comparator U1 is connected to the delay sub-circuit 210 , and the second input end of the first comparator U1 is connected to the delay sub-circuit 210 .

[0063] Among them, the first input terminal of the first comparator U1 can be the in-phase input terminal +, and the second input terminal of the first comparator U1 can be the inverting input terminal -; when the enabling circuit 100 is turned on, the first input terminal of the first comparator U1 is used to receive the first voltage signal, the second input terminal of the first comparator U1 is used to receive the second voltage signal, and the output terminal of the first comparator U1 outputs the first power supply control signal, and the first power supply control signal can be a high-level signal; when the enabling circuit 100 is turned off, the first input terminal of the first comparator U1 is used to receive the third voltage signal, the second input terminal of the first comparator U1 is used to receive the fourth voltage signal, and the output terminal of the first comparator U1 outputs the second power supply control signal, and the second power supply control signal can be a low-level signal.

[0064] In this embodiment, the comparison sub-circuit 220 includes a fifth resistor R5 and a first comparator U1 , so that the comparison sub-circuit 220 has a simple structure, a small volume, a low cost, and is easy to implement.

[0065] In one embodiment, reference Figure 3 The power supply circuit 300 includes an optocoupler sub-circuit 310 and a transformer sub-circuit 320 .

[0066] The optocoupler sub-circuit 310 is connected to the delay circuit 200 and the first pole of the battery module respectively. The optocoupler sub-circuit 310 is used to output a power-on signal according to the first power supply control signal, and output a power-off signal according to the second power supply control signal.

[0067] The transformer subcircuit 320 is respectively connected to the optocoupler subcircuit 310 and the second pole of the battery module, and is used to connect the load; the transformer subcircuit 320 is used to draw power from the battery module according to the power-drawing signal to supply power to the load, and to stop drawing power from the battery module according to the power-off signal to stop supplying power to the load.

[0068] The first pole of the battery module may be the negative pole BAT- of the battery module, and the second pole of the battery module may be the positive pole BAT+ of the battery module. The load may be the power conversion chip of the main control chip. The transformer subcircuit 320 draws power from the battery module according to the power-drawing signal and outputs it to the power conversion chip, which performs voltage conversion to supply power to the main control chip.

[0069] In this embodiment, the power supply circuit 300 includes an optocoupler sub-circuit 310 and a transformer sub-circuit 320 , so that the power supply circuit 300 has a simple structure, a small volume, a low cost, and is easy to implement.

[0070] In one embodiment, continue to refer to Figure 3The optocoupler subcircuit 310 includes a sixth resistor R6 and a first optocoupler isolator U2. The first end of the sixth resistor R6 is connected to the delay circuit 200, and the second end of the sixth resistor R6 is connected to the first input end of the first optocoupler isolator U2; the first output end of the first optocoupler isolator U2 is grounded, the second input end of the first optocoupler isolator U2 is connected to the transformer subcircuit 320, and the second output end of the first optocoupler isolator U2 is connected to the first pole of the battery module.

[0071] Among them, when the enabling circuit 100 is turned on, the first end of the sixth resistor R6 is used to receive the first power supply control signal, and the first optocoupler isolator U2 is turned on; when the enabling circuit 100 is turned off, the first end of the sixth resistor R6 is used to receive the second power supply control signal, and the first optocoupler isolator U2 is turned off.

[0072] In this embodiment, the optocoupler sub-circuit 310 includes a sixth resistor R6 and a first optocoupler isolator U2, so that the optocoupler sub-circuit 310 has a simple structure, a small volume, a low cost, and is easy to implement.

[0073] In one embodiment, continue to refer to Figure 3 The transformer sub-circuit 320 includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first transistor Q2, a first diode D1 and a first transformer T1.

[0074] The first end of the seventh resistor R7 is connected to the second pole of the battery module, the second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8, the second end of the eighth resistor R8 is connected to the optocoupler sub-circuit 310, the first end of the ninth resistor R9 is connected to the first end of the eighth resistor R8, the second end of the ninth resistor R9 is connected to the control end of the first transistor Q2, the first end of the first transistor Q2 is connected to the first end of the seventh resistor R7, the second end of the first transistor Q2 is connected to the first end of the first diode D1, the second end of the first diode D1 is connected to the primary side of the first transformer T1, and the secondary side of the first transformer T1 is used to connect the load.

[0075] Among them, the seventh resistor R7 and the eighth resistor R8 constitute another voltage divider circuit. The first transistor Q2 can be a MOSFET (Metal-Oxide Semiconductor Field Effect Transistor). When the first optocoupler isolator U2 is turned on, the first transistor Q2 is turned on, the primary winding of the first transformer T1 is powered, and the secondary side of the first transformer T1 supplies power to the main control chip; when the first optocoupler isolator U2 is turned off, the first transistor Q2 is turned off, the primary winding of the first transformer T1 cannot draw power from the battery module, and the secondary side of the first transformer T1 stops supplying power to the main control chip.

[0076] In this embodiment, the transformer sub-circuit 320 includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first transistor Q2, a first diode D1 and a first transformer T1, so that the transformer sub-circuit 320 has a simple structure, a small size, a low cost and is easy to implement.

[0077] In one embodiment, the first transformer T1 is a flyback transformer, the primary winding of the first transformer T1 is the primary winding of the flyback transformer, and the secondary winding of the first transformer T1 is the secondary winding of the flyback transformer.

[0078] In one embodiment, continue to refer to Figure 2 , the enabling circuit 100 includes a tenth resistor R10, an eleventh resistor R11 and a first transistor Q1.

[0079] The first end of the tenth resistor R10 is used to receive the enable control signal POWER_CTRL, and the second end of the tenth resistor R10 is connected to the control end of the first transistor Q1; the first end of the eleventh resistor R11 is connected to the control end of the first transistor Q1, and the second end of the eleventh resistor R11 is connected to the first end of the first transistor Q1; the first end of the first transistor Q1 is grounded, and the second end of the first transistor Q1 is connected to the delay circuit 200.

[0080] Among them, after the battery module is turned on, the main control chip outputs a first level signal, the first end of the tenth resistor R10 is used to receive the first level signal, and the first transistor Q1 is turned on to realize the conduction of the enabling circuit 100; when the battery module or the main control chip is in an abnormal working state, the main control chip outputs a second level signal, the first end of the tenth resistor R10 is used to receive the second level signal, and the first transistor Q1 is turned off to realize the shutdown of the enabling circuit 100.

[0081] In this embodiment, the enabling circuit 100 includes a tenth resistor R10, an eleventh resistor R11 and a first transistor Q1, so that the enabling circuit 100 has a simple structure, a small volume, a low cost and is easy to implement.

[0082] In one embodiment, reference Figure 4 The delayed shutdown circuit also includes a backup circuit 400.

[0083] The input end of the backup circuit 400 is used to receive the enable control signal POWER_CTRL, and the output end of the backup circuit 400 is connected to the power supply circuit 300. The backup circuit 400 is used to generate a first power supply control signal according to the first level signal to control the power supply of the battery module when the enable circuit 100 is abnormal.

[0084] In this embodiment, a backup circuit 400 is provided so that when the delayed shutdown circuit is in an abnormal working state, the backup circuit 400 can generate a first power supply control signal according to the first level signal and output it to the power supply circuit 300, so that the power supply circuit 300 controls the battery module to supply power normally, thereby ensuring the normal operation of the energy storage battery system.

[0085] In one embodiment, continue to refer to Figure 4 The standby circuit 400 includes a twelfth resistor R12 and a second diode D2. The first end of the twelfth resistor R12 is connected to the first end of the first resistor R1 for receiving the enable control signal POWER_CTRL; the first end of the second diode D2 is connected to the second end of the first resistor R1, and the second end of the second diode D2 is connected to the output end of the first comparator U1.

[0086] Continue to refer to Figure 4 , the delayed shutdown circuit provided in the embodiment of the present application is further explained by way of example:

[0087] After the battery module is turned on, the main control chip outputs a high-level signal, the first transistor Q1 is turned on, the reverse input terminal - of the first comparator U1 is pulled low, the non-inverting input terminal + of the first comparator U1 is divided by the third resistor R3 and the fourth resistor R4, the first comparator U1 outputs a high-level signal, the first optocoupler isolator U2 is turned on, based on the reasonably configured seventh resistor R7 and eighth resistor R8, the first transistor Q2 is turned on, based on the battery module, the primary winding of the first transformer T1 is energized, and the secondary side of the first transformer T1 normally supplies power to the main control chip. When the battery module or the main control chip is in an abnormal working state, the main control chip outputs a low-level signal, the first transistor Q1 is turned off, and the power signal 3.3V passes through the first resistor R1 and the second resistor R2 to charge the first capacitor C1, that is, the delayed shutdown time begins, and the main control chip performs fault recording or reset. When the voltage across the first capacitor C1 is greater than the voltage of the in-phase input terminal + of the first comparator U1, the delayed shutdown time ends, and the main control chip uses the delayed shutdown time to complete the fault recording or reset, the first comparator U1 outputs a low-level signal, the first optocoupler isolator U2 is turned off, the first transistor Q2 is turned off, the primary winding of the first transformer T1 cannot draw power from the battery module, and the secondary side of the first transformer T1 stops supplying power to the main control chip.

[0088] The voltage at the non-inverting input terminal + of the first comparator U1 can be expressed by formula (1); the voltage across the first capacitor C1 can be expressed by formula (2); and the expression of the delayed shutdown time can be derived according to formula (1) and formula (2), namely, formula (3).

[0089] (1)

[0090] (2)

[0091] (3)

[0092] Among them, U 1+ is the voltage at the non-inverting input terminal + of the first comparator U1; U C1 is the voltage across the first capacitor C1; τ is the time constant; t is the delayed shutdown time; C1' is the capacity of the first capacitor C1. It can be seen that the delayed shutdown time t can be adjusted by adjusting the resistance of at least one of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 or adjusting the capacity of the first capacitor C1.

[0093] The delayed shutdown circuit provided in the embodiment of the present application does not involve a supercapacitor. The delayed shutdown circuit has a simple structure, a small size, a low cost, and is easy to implement. The delayed shutdown circuit will not limit the selection of the power conversion chip, and the operation of the delayed shutdown circuit will not trigger the overcurrent protection of the power conversion chip.

[0094] An embodiment of the present application also provides a battery management system, comprising the delayed shutdown circuit described in any of the above embodiments.

[0095] The battery management system and the delayed shutdown circuit provided in the embodiment of the present application both belong to the same utility model concept, can solve the same technical problems, and achieve the same technical effects, and the repeated contents will not be repeated here.

[0096] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A delayed shutdown circuit, characterized in that: include: An enabling circuit, used to turn on or off according to a received enabling control signal; a delay circuit connected to the enabling circuit, configured to output a first power supply control signal according to a received power supply signal when the enabling circuit is turned on, and to output a second power supply control signal after a delayed shutdown time based on the received power supply signal when the enabling circuit is turned off, wherein the second power supply control signal is different from the first power supply control signal; A power supply circuit is connected to the delay circuit and is used to control the battery module to supply power according to the first power supply control signal, and to control the battery module to stop supplying power according to the second power supply control signal.

2. The delayed shutdown circuit according to claim 1, characterized in that: The delay circuit comprises: a delay subcircuit connected to the enabling circuit, configured to output a first voltage signal and a second voltage signal according to a received power signal when the enabling circuit is turned on, and to output a third voltage signal and a fourth voltage signal after a delayed shutdown time based on the received power signal when the enabling circuit is turned off; A comparison subcircuit is respectively connected to the delay subcircuit and the power supply circuit, and is used to output the first power supply control signal according to the first voltage signal and the second voltage signal, and to output the second power supply control signal according to the third voltage signal and the fourth voltage signal.

3. The delayed shutdown circuit according to claim 2, characterized in that: The delay subcircuit includes a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor; The first end of the first resistor is used to receive a power signal, and the second end of the first resistor is connected to the enabling circuit; The first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the comparison subcircuit; The first end of the third resistor is connected to the first end of the first resistor, and the second end of the third resistor is connected to the comparison subcircuit; The first end of the fourth resistor is connected to the second end of the third resistor, and the second end of the fourth resistor is grounded; The first end of the first capacitor is connected to the second end of the second resistor, and the second end of the first capacitor is grounded; The length of the delayed shutdown time is determined by the resistance values ​​of the first resistor, the second resistor, the third resistor and the fourth resistor and the capacity of the first capacitor.

4. The delayed shutdown circuit according to any one of claims 2 or 3, characterized in that: The comparison subcircuit includes a fifth resistor and a first comparator; A first end of the fifth resistor is connected to the delay sub-circuit, and a second end of the fifth resistor is connected to the output end of the first comparator; The first input terminal of the first comparator is connected to the delay sub-circuit, and the second input terminal of the first comparator is connected to the delay sub-circuit.

5. The delayed shutdown circuit according to claim 1, characterized in that: The power supply circuit comprises: an optical coupler circuit, connected to the delay circuit and the first electrode of the battery module respectively, and configured to output a power-on signal according to the first power supply control signal, and output a power-off signal according to the second power supply control signal; The transformer subcircuit is respectively connected to the optocoupler subcircuit and the second pole of the battery module, and is used to connect the load, wherein the transformer subcircuit is used to draw power from the battery module according to the power-drawing signal to supply power to the load, and to stop drawing power from the battery module according to the power-off signal to stop supplying power to the load.

6. The delayed shutdown circuit according to claim 5, characterized in that: The optocoupler subcircuit includes a sixth resistor and a first optocoupler isolator; The first end of the sixth resistor is connected to the delay circuit, and the second end of the sixth resistor is connected to the first input end of the first optical coupler isolator; The first output end of the first optocoupler isolator is grounded, the second input end of the first optocoupler isolator is connected to the transformer subcircuit, and the second output end of the first optocoupler isolator is connected to the first pole of the battery module.

7. The delayed shutdown circuit according to any one of claims 5 or 6, characterized in that: The voltage transformation subcircuit includes a seventh resistor, an eighth resistor, a ninth resistor, a first transistor, a first diode and a first transformer; The first end of the seventh resistor is connected to the second pole of the battery module, the second end of the seventh resistor is connected to the first end of the eighth resistor, the second end of the eighth resistor is connected to the optocoupler circuit, the first end of the ninth resistor is connected to the first end of the eighth resistor, the second end of the ninth resistor is connected to the control end of the first transistor, the first end of the first transistor is connected to the first end of the seventh resistor, the second end of the first transistor is connected to the first end of the first diode, the second end of the first diode is connected to the primary side of the first transformer, and the secondary side of the first transformer is used to connect a load.

8. The delayed shutdown circuit according to claim 1, characterized in that: The enabling circuit includes a tenth resistor, an eleventh resistor and a first transistor; The first end of the tenth resistor is used to receive the enable control signal, and the second end of the tenth resistor is connected to the control end of the first transistor; The first end of the eleventh resistor is connected to the control end of the first transistor, and the second end of the eleventh resistor is connected to the first end of the first transistor; The first end of the first transistor is grounded, and the second end of the first transistor is connected to the delay circuit.

9. The delayed shutdown circuit according to claim 1, characterized in that: The enabling circuit is used to be turned on when the enabling control signal is a first level signal, and turned off when the enabling control signal is a second level signal, the second level signal is different from the first level signal, and the delayed shutdown circuit further includes: A backup circuit, wherein the input end of the backup circuit is used to receive the enable control signal, the output end of the backup circuit is connected to the power supply circuit, and the backup circuit is used to generate the first power supply control signal according to the first level signal to control the power supply of the battery module when the enable circuit is abnormal.

10. A battery management system, characterized in that: It comprises the delayed shutdown circuit as described in any one of claims 1-9.

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