Circuit breaker, circuit breaker abnormality diagnosis method, and lithium battery system

Abstract

The application provides a circuit breaker, a circuit breaker anomaly diagnosis method and a lithium battery system, relates to the electrical field, solves the defects of the traditional circuit breaker using a relay, and comprises a battery module end and a battery pack system end; a switch channel; the battery module end and the battery pack system end are coupled with N mutually parallel switch channels; the switch channel is composed of a semiconductor switching device; when the N switch channels are abnormally diagnosed, at least one switch channel in the N switch channels is in a closed state. The application provides a circuit breaker using a semiconductor switching device, overcomes some defects of the current circuit breaker using a relay, and can timely detect and diagnose a faulty circuit breaker, a circuit breaker anomaly diagnosis method and a lithium battery system in the case of aging or uncontrolled failure of the circuit breaker.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electricity, in particular to a circuit breaker, a circuit breaker abnormality diagnosis method and a lithium battery system. BACKGROUND

[0002] The new energy automobile industry is booming, and new energy automobiles using lithium batteries as energy storage devices are becoming more and more popular. In the design of traditional lithium battery systems, relays are often selected as the preferred component for the main circuit breaker of the battery system.

[0003] However, due to the slow response of the relay action switch (more than 10 ms), it is not conducive to short-circuit protection, and the contact life will be greatly shortened in the case of arc. At the same time, the mechanical noise caused by the mechanical state switching of the relay during opening and closing will cause poor user experience, so in the application field of high-end lithium battery systems, especially in the application of 12V, 24V, 48V and other vehicle low-voltage lithium battery systems, semiconductor switching devices are becoming more and more popular as main circuit breakers.

[0004] Since the power metal-oxide-semiconductor field-effect transistor (MOSFET) has many advantages such as low cost, small size, light weight, low on-resistance, simple layout, etc., in the prior art, MOSFET is usually used as the preferred semiconductor switching circuit breaker. However, since the technology of using semiconductor switches as battery circuit breakers has not been widely used and is not yet mature, when a semiconductor switch is used as a circuit breaker in a lithium battery system, if the circuit breaker malfunctions, it is difficult to quickly and accurately diagnose the abnormal state of the semiconductor switching device, and it is also inconvenient to check the aging degree of the circuit breaker on a daily basis. SUMMARY

[0005] The present application provides a semiconductor switching device as a circuit breaker, which overcomes some of the defects of using relays as circuit breakers, and can detect and diagnose faulty circuit breakers in a timely manner when the circuit breaker is aging or uncontrolled failure.

[0006] In one aspect, the present application provides a circuit breaker, characterized in that it comprises:

[0007] a battery module end and a battery pack system end;

[0008] Switch channels, N switch channels coupled between the battery module end and the battery pack system end in parallel with each other, the switch channels being composed of semiconductor switching devices, the switch channels being used to control the on-off of the loop between the battery module end and the battery pack system end, wherein N is a natural number greater than or equal to 2;

[0009] In the abnormal diagnosis of the N switch channels, at least one of the N switch channels is in a closed state to keep the circuit breaker in a conducting state.

[0010] In a possible implementation of the present application, the switch channel includes:

[0011] A first switch group coupled with the battery module end;

[0012] A second switch group coupled with the first switch group and the battery pack system end;

[0013] The coupling point between the first switch group and the second switch group forms a channel potential point, the first switch group and the battery module end form an input potential point, and the second switch group and the battery pack system end form an output potential point.

[0014] In a possible implementation of the present application, the circuit breaker includes a drive module, and the drive module includes a first drive pin and a second drive pin;

[0015] The first switch group includes a first switch tube, and the first switch tube includes a first control electrode coupled with the first drive pin;

[0016] The second switch group includes a second switch tube, and the second switch tube includes a second control electrode coupled with the second drive pin.

[0017] In a possible implementation of the present application, the channel potential point includes a first channel potential point, the input potential point includes a first input potential point, and the output potential point includes a first output potential point;

[0018] The first switch tube includes a first main voltage electrode and a first auxiliary voltage electrode, and the second switch tube includes a second main voltage electrode and a second auxiliary voltage electrode;

[0019] The first main voltage electrode of the first switch tube is coupled with the second main voltage electrode of the second switch tube, and the first main voltage electrode and the second main voltage electrode form the first channel potential point;

[0020] The first auxiliary voltage pole of the first switch tube is coupled with the battery module end, and a first input potential point is formed between the first auxiliary voltage pole and the battery module end;

[0021] The second auxiliary voltage pole of the second switch tube is coupled with the battery pack system end, and the first output potential point is formed between the second auxiliary voltage pole and the battery pack system end.

[0022] In a possible implementation of the present application, the driving module comprises a third driving pin and a fourth driving pin;

[0023] The first switch group comprises a plurality of third switch tubes, each of which comprises a third control pole coupled with the third driving pin;

[0024] The second switch group comprises a plurality of fourth switch tubes, each of which comprises a fourth control pole coupled with the fourth driving pin.

[0025] In a possible implementation of the present application, the channel potential point comprises a plurality of second channel potential points, the input potential point comprises a second input potential point, and the output potential point comprises a second output potential point;

[0026] The third switch tube comprises a third main voltage pole and a third auxiliary voltage pole, and the fourth switch tube comprises a fourth main voltage pole and a fourth auxiliary voltage pole;

[0027] The third main voltage poles of the plurality of third switch tubes are respectively coupled with the fourth main voltage poles of the plurality of fourth switch tubes, and the plurality of connection points formed between the plurality of third main voltage poles and the plurality of fourth main voltage poles are all the second channel potential points, and the plurality of connection points are all coupled through wires;

[0028] The third auxiliary voltage poles of the plurality of third switch tubes are all coupled with the battery module end, and the second input potential point is formed between the third auxiliary voltage poles and the battery module end;

[0029] The fourth auxiliary voltage poles of the plurality of fourth switch tubes are all coupled with the battery pack system end, and the second output potential point is formed between the fourth auxiliary voltage poles and the battery pack system end.

[0030] In a possible implementation of the present application, a sampling resistor is coupled between the battery module end and the battery pack system end.

[0031] In another aspect, the present application provides a circuit breaker abnormality diagnosis method, which is applied to the circuit breaker, and comprises the following steps:

[0032] setting at least one of the switch channels to a closed state;

[0033] obtaining a first voltage value of the input potential point, a second voltage value of the output potential point, and N third voltage values of N channel potential points corresponding to the N switch channels at the current time;

[0034] diagnosing the semiconductor switch devices in the N switch channels according to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time to obtain a switch device abnormality diagnosis result.

[0035] In a possible implementation of the present application, when each of the N switch channels is set to a closed state;

[0036] The diagnosis of the semiconductor switch devices in the N switch channels according to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time to obtain a switch device abnormality diagnosis result includes:

[0037] When the second voltage value does not change, it is determined that the switch device abnormality diagnosis result is that all the semiconductor switch devices in the N switch channels are abnormal;

[0038] When the i-th third voltage value corresponding to the i-th switch channel is zero, and the (N-1) third voltage values corresponding to the remaining (N-1) switch channels are all equal to the first voltage value, it is determined that the switch device abnormality diagnosis result is that part of the semiconductor switch devices in the i-th switch channel are abnormal, where i is a natural number less than N;

[0039] When the N third voltage values corresponding to the N switch channels are all equal to the first voltage value, it is determined that the switch device abnormality diagnosis result is no diagnosis result.

[0040] In a possible implementation of the present application, when the switch device abnormality diagnosis result is no diagnosis result, the first switch group in the j-th switch channel of the N switch channels is set to an open state, and each of the remaining (N-1) switch channels is set to a closed state, where j is a natural number less than N;

[0041] The diagnosis of the semiconductor switch devices in the N switch channels according to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time to obtain a switch device abnormality diagnosis result includes:

[0042] when the jth third voltage value, the other (N-1) third voltage values, and the second voltage value are all voltage drop values of the input potential point, determining that the switch device abnormality diagnosis result is that the first switch group in the jth switch channel is abnormal;

[0043] when the jth third voltage value and the second voltage value are both voltage drop values of the input potential point, and the other (N-1) third voltage values are all equal to the first voltage value, determining that the switch device abnormality diagnosis result is that the second switch group in the jth switch channel is abnormal;

[0044] when the jth third voltage value is greater than the voltage drop value of the input potential point and less than the first voltage value, and the other (N-1) third voltage values and the second voltage value are all equal to the first voltage value, determining that the switch device abnormality diagnosis result is that all semiconductor switch devices in the other (N-1) switch channels are normal.

[0045] In a possible implementation of the present application, when the switch device abnormality diagnosis result is that all semiconductor switch devices in the other (N-1) switch channels are normal, the first switch group in the jth switch channel is set to a closed state, and the first switch groups in the other (N-1) switch channels are all set to an open state.

[0046] The first voltage value, the second voltage value, and the N third voltage values obtained at the current time are used to diagnose semiconductor switch devices in the N switch channels, and a switch device abnormality diagnosis result is obtained, including:

[0047] when the jth third voltage value, the other (N-1) third voltage values, and the second voltage value are all voltage drop values of the input potential point, determining that the switch device abnormality diagnosis result is that the first switch group in the jth switch channel is abnormal;

[0048] when the jth third voltage value is equal to the first voltage value, and the second voltage value and the other (N-1) third voltage values are all voltage drop values of the input potential point, determining that the switch device abnormality diagnosis result is that the second switch group in the jth switch channel is abnormal;

[0049] When the jth third voltage value, the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the switch device abnormality diagnosis result is that all semiconductor switch devices in the jth switch channel do not have abnormality, i.e., all semiconductor switch devices in the N switch channels do not have abnormality.

[0050] In a possible implementation of the present application, when the switch device abnormality diagnosis result is no diagnosis result, the second switch group in the kth switch channel of the N switch channels is set to an open state, and each of the remaining (N-1) switch channels is set to a closed state, where k is a natural number less than N.

[0051] The first voltage value, the second voltage value and the N third voltage values obtained at the current moment are used to diagnose semiconductor switch devices in the N switch channels to obtain a switch device abnormality diagnosis result, including:

[0052] When the kth third voltage value corresponding to the kth switch channel is equal to the first voltage value, and the second voltage value and the remaining (N-1) third voltage values are all voltage drop values of the input potential point, it is determined that the switch device abnormality diagnosis result is that the first switch group in the remaining (N-1) switch channels has abnormality.

[0053] When the kth third voltage value and the remaining (N-1) third voltage values are all equal to the first voltage value, and the second voltage value is the voltage drop value of the input potential point, it is determined that the switch device abnormality diagnosis result is that the second switch group in the remaining (N-1) switch channels has abnormality.

[0054] When the kth third voltage value, the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the switch device abnormality diagnosis result is that all semiconductor switch devices in the remaining (N-1) switch channels do not have abnormality.

[0055] In a possible implementation of the present application, when the switch device abnormality diagnosis result is that all semiconductor switch devices in the remaining (N-1) switch channels do not have abnormality, the second switch group in the kth switch channel is set to a closed state, and the second switch group in the remaining (N-1) switch channels is set to an open state.

[0056] The first voltage value, the second voltage value and the N third voltage values obtained at the current moment are used to diagnose the semiconductor switching devices in the N switching channels, and a switching device abnormality diagnosis result is obtained, comprising:

[0057] When the kth third voltage value corresponding to the kth switching channel and the second voltage value are both voltage drop values of the input potential point, and the remaining (N-1) third voltage values are equal to the first voltage value, it is determined that the switching device abnormality diagnosis result is that the first switching group of the kth switching channel has an abnormality;

[0058] When the kth third voltage value and the remaining (N-1) third voltage values are all equal to the first voltage value, and the second voltage value is the voltage drop value of the input potential point, it is determined that the switching device abnormality diagnosis result is that the second switching group of the kth switching channel has an abnormality;

[0059] When the kth third voltage value, the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the switching device abnormality diagnosis result is that all semiconductor switching devices of the kth switching channel do not have an abnormality, that is, all semiconductor switching devices in the N switching channels do not have an abnormality.

[0060] In a possible implementation of the application, the switching device abnormality diagnosis result includes a short-circuit abnormality diagnosis result, when the first switching group and the second switching group in the mth switching channel of the N switching channels are both set to an open state, and the remaining (N-1) switching channels are all set to a closed state;

[0061] The first voltage value, the second voltage value and the N third voltage values obtained at the current moment are used to diagnose the semiconductor switching devices in the N switching channels, and a switching device abnormality diagnosis result is obtained, comprising:

[0062] When the mth third voltage value corresponding to the mth switching channel is zero, and the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the short-circuit abnormality diagnosis result is that the mth switching channel does not have a short-circuit abnormality;

[0063] When the mth third voltage value, the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the short-circuit abnormality diagnosis result is that the first switching group and the second switching group of the mth switching channel both have a short-circuit abnormality.

[0064] In another aspect, the application also provides a lithium battery system, which adopts the abnormal diagnosis method of the circuit breaker.

[0065] In the application, the semiconductor switching device is used as a switching channel, i.e., the semiconductor switching device is used as the circuit breaker. Compared with the traditional method of using a relay as the circuit breaker, the application can effectively avoid the problems of the relay, such as load circuit breaking, mechanical noise pollution, and easy damage of the relay contact, and has the advantages of fast response speed, high integration, and small electrical volume. Meanwhile, the circuit breaker of the application adopts a plurality of parallel switching channels. When a fault occurs in the application to the battery system or other equipment, at least one of the N switching channels is in a closed state, so that the circuit breaker remains in a conducting state. Then, the other switching channels are diagnosed to diagnose the semiconductor switching device that is abnormal or uncontrolled in the switching channel, so that the fault can be detected and diagnosed in time, and the safety is higher. BRIEF DESCRIPTION OF DRAWINGS

[0066] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0067] Figure 1 is a schematic structural diagram of one embodiment of the circuit breaker provided by the application;

[0068] Figure 2 is a schematic structural diagram of one embodiment of the circuit breaker provided by the application;

[0069] Figure 3 is a schematic structural diagram of one embodiment of the circuit breaker provided by the application;

[0070] Figure 4 is a schematic flow diagram of one embodiment of the abnormal diagnosis method of the circuit breaker provided by the application;

[0071] Figure 5 is a schematic flow diagram of one embodiment of the abnormal diagnosis method of the circuit breaker provided by the application. DETAILED DESCRIPTION

[0072] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, any other embodiments obtained by a person of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0073] In the description of the present application, the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0074] In the present application, the word "exemplary" is used to mean "serving as an example, instance, or illustration". Any implementation described as "exemplary" in the present application is not necessarily to be construed as preferred or advantageous over other implementations. The following description is presented to enable any person skilled in the art to make and use the application. In the following description, for the purposes of explanation, numerous details are set forth. It should be appreciated that a person having ordinary skill in the art can realize further implementations of the present application without using these specific details. In other instances, well known structures and processes are not elaborated in order not to obscure the description of the present application with unnecessary detail. Thus, the present application is not intended to be limited by the implementations shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

[0075] The embodiments of the present application provide a circuit breaker, a circuit breaker abnormality diagnosis method and a lithium battery system, which are described in detail as follows.

[0076] As shown in FIG. 1, it is a schematic structural diagram of a circuit breaker in an embodiment of the present application, which comprises: Figure 1

[0077] A battery module end and a battery pack system end.

[0078] A switch channel, the battery module end and the battery pack system end are coupled with N switch channels in parallel with each other, the switch channel is composed of a semiconductor switching device, and the switch channel is used to control the on-off of the loop between the battery module end and the battery pack system end, wherein N is a natural number greater than or equal to 2.

[0079] When diagnosing the N switch channels, at least one of the N switch channels is in a closed state to keep the circuit breaker in a conducting state.

[0080] ​The semiconductor switching device is used as a switching channel in the application, that is, the semiconductor switching device is used as a circuit breaker. Compared with the traditional way of using a relay as a circuit breaker, the application can effectively avoid the problems of the relay, such as load circuit breaking, mechanical noise pollution, and easy damage of the relay contact, and has the advantages of fast response speed, high integration, and small electrical volume. Meanwhile, the circuit breaker of the application uses multiple parallel switching channels. When a fault occurs in the application in a battery system or other equipment, at least one of the N switching channels can be in a closed state to keep the circuit breaker in a conducting state. When the circuit breaker is applied to a vehicle voltage power supply, the battery pack can be always connected to the vehicle low-voltage power supply network, so that the abnormal diagnosis of other switching channels can be performed to diagnose the semiconductor switching device that has an aging abnormality or an uncontrolled abnormality, thereby timely detecting and diagnosing the fault and improving safety.

[0081] In the embodiment, N is a natural number greater than or equal to 2, and N can be 2, 3, or 4, and the like. As shown in FIGS. 1 and 2, the circuit breaker of the application can include two groups of switching channels, or three groups of switching channels, and the number of switching channels can be set as needed. The application does not make more specific limitations on the number of switching channels in the circuit breaker, and all substantially identical schemes are within the protection scope of the application. Figure 2 and Figure 3 As shown in FIGS. 1 and 2, the circuit breaker of the application can include two groups of switching channels, or three groups of switching channels, and the number of switching channels can be set as needed. The application does not make more specific limitations on the number of switching channels in the circuit breaker, and all substantially identical schemes are within the protection scope of the application.

[0082] In addition, in the embodiment, if the circuit breaker is applied to a battery system, multiple circuit breakers are used in parallel in each battery system to achieve the scheme of enhancing the overcurrent capacity, which should also be included in the protection scope of the patent.

[0083] In another embodiment of the application, the switching channel includes:

[0084] The first switch group is coupled with the battery module end.

[0085] The second switch group is coupled with the first switch group and the battery pack system end.

[0086] The coupling point between the first switch group and the second switch group forms a channel potential point, the first switch group and the battery module end form an input potential point, and the second switch group and the battery pack system end form an output potential point.

[0087] In the application process, the first switch group and the second switch group in the switching channel are used to control the on-off of the circuit breaker between the battery module end and the battery pack system end. During the operation of the circuit breaker, the voltage of the input potential point, the channel potential point, and the output potential point can be detected to diagnose the abnormality of the semiconductor switch in the circuit breaker.

[0088] As Figure 2 and Figure 3 shown, at least one switch tube can be included in each of the first switch group and the second switch group, the number of switch tubes in the first switch group corresponds to the number of switch tubes in the second switch group one by one, for example, when two switch tubes are included in the first switch group, two switch tubes corresponding to the two switch tubes in the first switch group are also included in the second switch group. The switch tubes in the first switch group and the second switch group can all use triodes, MOS tubes, thyristors or other devices that can realize the switching function. In this application, the first switch group and the second switch group both use Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFET).

[0089] The following specifically describes the case where one switch tube and two switch tubes are included in the first switch group and the second switch group.

[0090] In another embodiment of the present application, as Figure 2 shown, the circuit breaker includes two switch channels, when the first switch group and the second switch group each include one switch tube, the circuit breaker includes a driving module, the driving module includes a first driving pin and a second driving pin;

[0091] The first switch group includes a first switch tube, and the first switch tube includes a first control electrode coupled to the first driving pin;

[0092] The second switch group includes a second switch tube, and the second switch tube includes a second control electrode coupled to the second driving pin.

[0093] Specifically, one of the switch channels includes a first switch group S1 and a second switch group S2, the first switch group S1 is a charge-enabled MOSFET group, and the second switch group S2 is a discharge-enabled MOSFET group. The first switch group S1 includes a first switch tube Q1, and the first control electrode of the first switch tube Q1 is a gate. The second switch group S2 includes a second switch tube Q2, and the second control electrode of the second switch tube Q2 is a gate, that is, the gate of the first switch tube Q1 is coupled to the first driving pin GS1 of the driving module, and the gate of the second switch tube Q2 is coupled to the second driving pin GS2 of the driving module.

[0094] In the application process, the conduction or turn-off of the first switch tube Q1 is controlled by the level change of the first driving pin GS1 of the driving module, and the conduction or turn-off of the second switch tube Q2 is controlled by the level change of the second driving pin GS2 of the driving module, thereby realizing the on-off of the switch channel.

[0095] Similarly, the embodiment can be understood as: the first switch group S3 and the second switch group S4 constitute another switch channel, wherein the first switch group S3 has the same function as the first switch group S1, and the second switch group S4 has the same function as the second switch group S2, that is, the first switch group S3 is a charging enable MOSFET group, and the second switch group S4 is a discharging enable MOSFET group, the first switch group S3 includes the first switch tube Q3, the first control electrode of the first switch tube Q3 is the gate, the second switch group S4 includes the second switch tube Q4, the first control electrode of the second switch tube Q4 is the gate, the gate of the first switch tube Q3 is coupled with the first driving pin GS3 of the driving module, and the gate of the second switch tube Q4 is coupled with the second driving pin GS4 of the driving module.

[0096] In the application process, the conduction or turn-off of the first switch tube Q3 is controlled through the level change of the first driving pin GS3 of the driving module, and the conduction or turn-off of the second switch tube Q4 is controlled through the level change of the second driving pin GS4 of the driving module, so as to realize the on-off of the switch channel.

[0097] In another embodiment of the present application, as shown in Figure 2 When the first switch group and the second switch group each include one switch tube, the channel potential point includes a first channel potential point, the input potential point includes a first input potential point, and the output potential point includes a first output potential point.

[0098] The first switch tube includes a first main voltage pole and a first auxiliary voltage pole, and the second switch tube includes a second main voltage pole and a second auxiliary voltage pole.

[0099] The first main voltage pole of the first switch tube is coupled with the second main voltage pole of the second switch tube, and the first main voltage pole and the second main voltage pole form the first channel potential point therebetween.

[0100] The first auxiliary voltage pole of the first switch tube is coupled with the battery module end, and the first auxiliary voltage pole and the battery module end form the first input potential point therebetween.

[0101] The second auxiliary voltage pole of the second switch tube is coupled with the battery pack system end, and the second auxiliary voltage pole and the battery pack system end form the first output potential point therebetween.

[0102] In the embodiment, the first switch tube includes a first main voltage pole and a first auxiliary voltage pole, and the first main voltage pole and the first auxiliary voltage pole can each be the source or the drain of the first switch tube. When the first main voltage pole of the first switch tube is the source, the first auxiliary voltage pole of the first switch tube is the drain. When the first main voltage pole of the first switch tube is the drain, the first auxiliary voltage pole of the first switch tube is the source.

[0103] Similarly, the second switching transistor includes a second main voltage terminal and a second secondary voltage terminal. Both the second main voltage terminal and the second secondary voltage terminal can be the source or the drain of the second switching transistor. When the second main voltage terminal of the second switching transistor is the source, the second secondary voltage terminal of the second switching transistor is the drain. When the second main voltage terminal of the second switching transistor is the drain, the second secondary voltage terminal of the second switching transistor is the source.

[0104] For example, such as Figure 2 As shown, the first main voltage terminal of the first switching transistor is set as the source, and the first secondary voltage terminal of the first switching transistor is set as the drain. The second main voltage terminal of the second switching transistor is set as the source, and the second secondary voltage terminal of the second switching transistor is set as the drain.

[0105] In this embodiment, when the first switch group S1 includes the first switch transistor Q1 and the second switch group S2 includes the second switch transistor Q2, specifically:

[0106] The source of the first switching transistor Q1 and the source of the second switching transistor Q2 are coupled together to form the first channel potential point VS1. The drain of the first switching transistor Q1 is coupled to the positive terminal of the battery module to form the first input potential point BAT+. The drain of the second switching transistor Q2 is coupled to the positive terminal of the battery pack system to form the first output potential point KL30. By diagnosing the potentials of the first channel potential point VS1, the first input potential point BAT+, and the first output potential point KL30, abnormalities in the switching channel within the circuit breaker can be diagnosed.

[0107] Similarly, when the first switch group S1 includes the first switch transistor Q3 and the second switch group S2 includes the second switch transistor Q4, specifically:

[0108] The source of the first switching transistor Q3 and the source of the second switching transistor Q4 are coupled together to form the first channel potential point VS2. The drain of the first switching transistor Q3 is coupled to the positive terminal of the battery module to form the first input potential point BAT+. The drain of the second switching transistor Q4 is coupled to the positive terminal of the battery pack system to form the first output potential point KL30. By diagnosing the potentials of the first channel potential point VS2, the first input potential point BAT+, and the first output potential point KL30, abnormalities in the switching channel within the circuit breaker can be diagnosed.

[0109] To enhance the overcurrent capacity of the circuit breaker, the number of MOSFET devices in the first switching group S1 and the second switching group S2 can be increased according to actual needs. That is, the number of MOSFET devices can be increased. Figure 2 The number of MOSFETs in MOSFET groups S1, S2, S3, and S4 is arranged as follows: Figure 3The shown circuit breaker, in particular, the MOSFET groups S1, S2, S3, S4 each contain two MOSFET devices, so that in the case of a constant overcurrent capability of a single MOSFET, Figure 3 The shown circuit breaker has a higher overcurrent capability than Figure 2 The shown circuit breaker. In the following, each switch channel comprising a plurality of switch tubes is described in detail.

[0110] In another embodiment of the present application, as Figure 3 shown, the circuit breaker comprises two switch channels, when the first switch group and the second switch group each comprise a plurality of switch tubes, the drive module comprises a third drive pin and a fourth drive pin;

[0111] The first switch group comprises a plurality of third switch tubes, each of which comprises a third control electrode coupled to the third drive pin;

[0112] The second switch group comprises a plurality of fourth switch tubes, each of which comprises a fourth control electrode coupled to the fourth drive pin.

[0113] In particular, as Figure 3 shown, one of the switch channels comprises a first switch group S5 and a second switch group S6, the first switch group S5 is a charge-enabled MOSFET group, and the second switch group S6 is a discharge-enabled MOSFET group.

[0114] The first switch group S5 comprises a plurality of third switch tubes, i.e. a third switch tube Q5 and a third switch tube Q6, the third control electrodes of the third switch tube Q5 and the third switch tube Q6 are both gates, and the gates of the third switch tube Q5 and the third switch tube Q6 are both coupled to the third drive pin GS5 of the drive module;

[0115] The second switch group S6 comprises a plurality of fourth switch tubes, i.e. a fourth switch tube Q7 and a fourth switch tube Q8, the fourth control electrodes of the fourth switch tube Q7 and the fourth switch tube Q8 are both gates, and the gates of the fourth switch tube Q7 and the fourth switch tube Q8 are both coupled to the fourth drive pin GS6 of the drive module.

[0116] In the application process, the third switch tube Q5 and the third switch tube Q6 are controlled to be turned on or turned off simultaneously by the level change of the third drive pin GS5 of the drive module, and the fourth switch tube Q7 and the fourth switch tube Q8 are controlled to be turned on or turned off simultaneously by the level change of the fourth drive pin GS6 of the drive module, so as to realize the on-off of the switch channel.

[0117] Similarly, the embodiment can be understood as: the first switch group S7 and the second switch group S8 constitute another switch channel, wherein the first switch group S7 has the same function as the first switch group S5, and the second switch group S8 has the same function as the second switch group S6, that is, the first switch group S7 is a charging enable MOSFET group, and the second switch group S8 is a discharging enable MOSFET group.

[0118] The first switch group S7 includes a plurality of third switch tubes, that is, the third switch tube Q9 and the third switch tube Q10, and the third control electrode of the third switch tube Q9 and the third switch tube Q10 is the gate, and the gate of the third switch tube Q9 and the gate of the third switch tube Q10 are coupled with the third drive pin GS7 of the driving module;

[0119] The second switch group S6 includes a plurality of fourth switch tubes, that is, the fourth switch tube Q11 and the fourth switch tube Q12, and the fourth control electrode of the fourth switch tube Q11 and the fourth switch tube Q12 is the gate, and the gate of the fourth switch tube Q11 and the gate of the fourth switch tube Q12 are coupled with the fourth drive pin GS8 of the driving module.

[0120] In the application process, the conduction or turn-off of the third switch tube Q9 and the third switch tube Q10 is simultaneously controlled through the level change of the third drive pin GS7 of the driving module, and the conduction or turn-off of the fourth switch tube Q11 and the fourth switch tube Q12 is simultaneously controlled through the level change of the fourth drive pin GS8 of the driving module, so as to realize the on-off of the switch channel.

[0121] That is, in the embodiment, the gates of all MOSFETs in the first switch group S5 are connected to the same third drive pin GS5 of the same driving module, so that all MOSFETs in the first switch group S5 are synchronously controlled. The second switch group S6, and the first switch group S7 and the second switch group S8 of another switch channel are the same, so as to increase the overcurrent capacity of the circuit breaker proposed in the application.

[0122] In another embodiment of the application, the channel potential point includes a plurality of second channel potential points, the input potential point includes a second input potential point, and the output potential point includes a second output potential point;

[0123] The third switch tube includes a third main voltage pole and a third auxiliary voltage pole, and the fourth switch tube includes a fourth main voltage pole and a fourth auxiliary voltage pole;

[0124] The third main voltage poles of the plurality of third switch tubes are respectively coupled with the fourth main voltage poles of the plurality of fourth switch tubes, and the plurality of connection points formed between the plurality of third main voltage poles and the plurality of fourth main voltage poles are all second channel potential points, and the plurality of connection points are all coupled through wires;

[0125] The third sub-voltage poles of the plurality of third switch tubes are coupled with the battery module end, and the second input potential point is formed between the third sub-voltage poles and the battery module end.

[0126] The fourth sub-voltage poles of the plurality of fourth switch tubes are coupled with the battery pack system end, and the second output potential point is formed between the fourth sub-voltage poles and the battery pack system end.

[0127] In the embodiment, the third switch tube includes a third main voltage pole and a third sub-voltage pole, and the third main voltage pole and the third sub-voltage pole can be the source or the drain of the third switch tube. When the third main voltage pole of the third switch tube is the source, the third sub-voltage pole of the third switch tube is the drain. When the third main voltage pole of the third switch tube is the drain, the third sub-voltage pole of the third switch tube is the source.

[0128] Similarly, the fourth switch tube includes a fourth main voltage pole and a fourth sub-voltage pole, and the fourth main voltage pole and the fourth sub-voltage pole can be the source or the drain of the fourth switch tube. When the fourth main voltage pole of the fourth switch tube is the source, the fourth sub-voltage pole of the fourth switch tube is the drain. When the fourth main voltage pole of the fourth switch tube is the drain, the fourth sub-voltage pole of the fourth switch tube is the source.

[0129] For example, as shown in FIG. 3, the third main voltage pole of the third switch tube is set as the source, and the third sub-voltage pole of the third switch tube is set as the drain. The fourth main voltage pole of the fourth switch tube is set as the source, and the fourth sub-voltage pole of the fourth switch tube is set as the drain. Figure 3

[0130] That is, in the embodiment, when the first switch group S5 includes the third switch tube Q5 and the third switch tube Q6, and the second switch group S6 includes the fourth switch tube Q7 and the fourth switch tube Q8, specifically:

[0131] The source of the third switch tube Q5 and the source of the fourth switch tube Q7 are coupled, the source of the third switch tube Q6 and the source of the fourth switch tube Q8 are coupled, a connection point is formed between the third switch tube Q5 and the fourth switch tube Q7, a connection point is formed between the third switch tube Q6 and the fourth switch tube Q8, the two connection points are coupled through a wire, and any one of the two connection points can be used as the second channel potential point VS3. The drain of the third switch tube Q5 and the drain of the third switch tube Q6 are coupled with the positive electrode of the battery module end and form the second input potential point BAT+. The drain of the fourth switch tube Q7 and the drain of the fourth switch tube Q8 are coupled with the positive electrode of the battery pack system end and form the second output potential point KL30. By diagnosing the potentials of the second channel potential point VS3, the second input potential point BAT+ and the second output potential point KL30, the abnormal diagnosis of the switch channel in the circuit breaker can be realized.

[0132] ​Similarly, when the first switch group S7 includes the third switch Q9 and the third switch Q10, and the second switch group S8 includes the fourth switch Q11 and the fourth switch Q12, specifically:

[0133] The source of the third switch Q9 and the source of the fourth switch Q11 are coupled, the source of the third switch Q10 and the source of the fourth switch Q12 are coupled, and a connection point is formed between the third switch Q9 and the fourth switch Q11, and a connection point is formed between the third switch Q10 and the fourth switch Q12. The two connection points are coupled by a wire, and any one of the two connection points can serve as the second channel potential point VS4. The drain of the third switch Q9 and the drain of the third switch Q10 are both coupled to the positive electrode of the battery module end and form the second input potential point BAT+. The drain of the fourth switch Q11 and the drain of the fourth switch Q12 are both coupled to the positive electrode of the battery pack system end and form the second output potential point KL30. By diagnosing the potentials of the second channel potential point VS4, the second input potential point BAT+, and the second output potential point KL30, the abnormal diagnosis of the switch channel in the circuit breaker can be realized.

[0134] In another embodiment of the present application, a sampling resistor is coupled between the battery module end and the battery pack system end, and the sampling resistor and the battery pack system end form a third output potential point. The sampling resistor can be as shown by the shunt in Figure 2 and Figure 3 The third output potential point can be the third output potential point KL30 as shown in Figure 2 and Figure 3 By the sampling resistor, the potentials of the battery module end and the battery pack system end can be collected, facilitating the diagnosis of the abnormality of the MOSFET device in the circuit breaker. In the present embodiment, the sampling resistor coupled between the battery module end and the battery pack system end can also be replaced by other loads having the same function, such as a wire, etc., which is not specifically limited here.

[0135] To realize the diagnosis of whether the MOSFET is controlled or aged, the abnormal diagnosis of the MOSFET can be realized by collecting the voltages of the source of the circuit breaker switch channel and the two drains relative to the negative electrode of the battery pack. The MOSFET abnormal scenarios include: 1. MOSFET internal short circuit, unable to be controlled to open; 2. MOSFET internal circuit breaker, unable to be controlled to close; 3. If the MOSFET is aged, it will present a large on-resistance after being controlled to close, and the abnormal phenomenon is similar to the failure phenomenon of the MOSFET internal circuit breaker unable to be controlled to close, so they can be classified and processed.

[0136] Therefore, in order to better implement the circuit breaker in the embodiments of the present application, based on the circuit breaker, the embodiments of the present application further provide a circuit breaker abnormality diagnosis method, which is applied to the circuit breaker as shown in the drawings, and is an embodiment flow diagram of the circuit breaker abnormality diagnosis method in the embodiments of the present application. The circuit breaker abnormality diagnosis method comprises steps 401-403. Figure 4

[0137] 401. At least one switch channel in the N switch channels is set to a closed state.

[0138] During the diagnosis process, when a group of switch channels in the circuit breaker is in the diagnosis period, the other N-1 groups of switch channels should be able to maintain the normally closed mode, so as to maintain the circuit breaker in the on state when diagnosing other switch channels, thereby avoiding the circuit breaker having to frequently switch to the off state due to the diagnosis work of the circuit breaker, and thus maintaining the long-term normal use of the circuit breaker.

[0139] 402. The first voltage value of the input potential point, the second voltage value of the output potential point, and the third voltage value of the N channel potential points corresponding to the N switch channels at the current time are obtained. 403. The semiconductor switching devices in the N switch channels are diagnosed according to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time, to obtain a switching device abnormality diagnosis result.

[0140] Since the circuit breaker is always in the on state, during the diagnosis process, the voltage values of the input potential point, the output potential point, and the N channel potential points corresponding to the N switch channels at the current time are obtained, and it is judged which group or which specific semiconductor device in the N channels has an abnormality based on the voltage values of the above-mentioned potential points.

[0141] In the present application, since the switch tubes used in the switch channels are all MOSFET tubes, the control state of each MOSFET tube in the switch channel can be identified by obtaining the voltage values of the input potential point of the circuit breaker, the source and two drains of the MOSFET tube, and the output potential point, so as to judge the MOSFET tube that has an abnormality. Next, the multiple different cases of the N switch channels having an abnormality are described in detail.

[0142] In another embodiment of the present application, when each switch channel in the N switch channels is set to a closed state;

[0143] According to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time, the semiconductor switching devices in the N switch channels are diagnosed to obtain a switching device abnormality diagnosis result, which comprises:

[0144] ​When the second voltage value does not have a voltage change, it is determined that the switch device abnormality diagnosis result is that all semiconductor switch devices in the N switch channels have abnormalities;

[0145] When the i-th third voltage value corresponding to the i-th switch channel is zero, and the (N-1) third voltage values corresponding to the remaining (N-1) switch channels are all equal to the first voltage value, it is determined that the switch device abnormality diagnosis result is that part of the semiconductor switch devices in the i-th switch channel have abnormalities, where i is a natural number less than N;

[0146] When the N third voltage values corresponding to the N switch channels are all equal to the first voltage value, it is determined that the switch device abnormality diagnosis result is that there is no diagnosis result.

[0147] With the above technical solution, when the N switch channels are all in a closed state, i.e., the circuit breaker is in a closed state, if there is no potential change at the current potential point, it indicates that all MOSFET tubes in the N switch channels are not normally turned on, i.e., all MOSFET tubes in the N switch channels do not have abnormalities.

[0148] However, if the third voltage value of any one or more of the N switch channels is zero, it indicates that the semiconductor device in the any one or more of the N switch channels is turned on, and it can be determined that part of the semiconductor devices in the any one or more of the switch channels have controlled closing abnormalities or obvious aging.

[0149] If the N third voltage values corresponding to the N switch channels are all equal to the first voltage value, it may be that all semiconductor devices in the N switch channels do not have abnormalities, or all or part of the semiconductor devices in the N switch channels have short-circuit abnormalities, so it is not possible to determine the specific abnormality of the semiconductor devices in the N switch channels, and further inspection is required. For example, as shown in Figure 3 and Figure 5 When N=2, if both of the 2 switch channels are in a closed state, and VS3 and VS4 do not have potential changes, it can be directly determined that both of the 2 switch channels have faults; if the voltage value of any one of VS3 and VS4 is zero, it can be determined that part of the MOSFET tubes in the corresponding any one of the 2 switch channels have abnormalities; but if the voltage values of VS3 and VS4 are all equal to the voltage value at BAT+, it is not possible to determine whether the 2 switch channels have abnormalities.

[0150] In another embodiment of the present application, when the switch device abnormality diagnosis result is no diagnosis result, the first switch group in the jth switch channel of the N switch channels is set to an open state, and the remaining (N-1) switch channels are each set to a closed state, where j is a natural number less than N;

[0151] According to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time, the semiconductor switch devices in the N switch channels are diagnosed to obtain a switch device abnormality diagnosis result, including:

[0152] When the jth third voltage value corresponding to the jth switch channel, the remaining (N-1) third voltage values, and the second voltage value are all voltage drop values of the input potential point, it is determined that the switch device abnormality diagnosis result is that the first switch group in the remaining (N-1) switch channels all have abnormalities;

[0153] When the jth third voltage value and the second voltage value are both voltage drop values of the input potential point, and the remaining (N-1) third voltage values are all equal to the first voltage value, it is determined that the switch device abnormality diagnosis result is that the second switch group in the remaining (N-1) switch channels all have abnormalities;

[0154] When the jth third voltage value is greater than the voltage drop value of the input potential point and less than the first voltage value, and the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the switch device abnormality diagnosis result is that all semiconductor switch devices in the remaining (N-1) switch channels do not have abnormalities.

[0155] For the case where the N third voltage values corresponding to the N switch channels are all equal to the first voltage value, it is not possible to determine the specific abnormalities of the semiconductor devices in the N switch channels, and further abnormality judgment is required. Specifically, the first switch group in the jth switch channel of the N switch channels can be set to an open state, and the other switch channels can be set to a closed state. Here, j can be any natural number less than N. The third voltage value of the jth switch channel is used as a judgment reference, and it can be determined whether the first switch group and the second switch group in the N switch channels have abnormal conditions.

[0156] Specifically, as shown in Figure 3 and Figure 5 When N=2, if the two switch channels are both in a closed state, the voltage values of VS3 and VS4 are both equal to the voltage value at BAT+, and it is not possible to determine whether the two switch channels have abnormalities, the first switch group (Q5 and Q6) of the switch channel where VS3 is located is set to an open state, and the switch channel where VS4 is located is set to a closed state;

[0157] If the voltage values of VS3, VS4 and KL30 are all the voltage drop values of BAT+, and the first switch group of the switch channel where VS3 is located is in the open state, the potential of VS4 is the same as that of KL30, so it can be concluded that the first switch group (Q9 and Q10) of the switch channel where VS4 is located has abnormal controlled closing or is obviously aged;

[0158] If the voltage value of VS3 is the voltage drop value of BAT+, and the voltage value of VS4 is the voltage value of BAT+, it indicates that the potential of BAT+ is not the same as that of KL30, that is, the second switch group of the switch channel where VS4 is located is not conducting, so it can be concluded that the second switch group (Q11 and Q12) of the switch channel where VS4 is located has abnormal controlled closing or is obviously aged;

[0159] If the voltage value of VS3 is greater than the voltage drop value of BAT+ and less than the voltage value of BAT+, and the voltage values of VS4 and KL30 are both less than the voltage value of BAT+, based on the above judgment steps, it can be determined that all the semiconductor switching devices in the switch channel where VS4 is located are normal. In another embodiment of the present application, when the switching device abnormality diagnosis result is that all the semiconductor switching devices in the remaining (N-1) switch channels are normal, the first switch group in the jth switch channel is set to the closed state, and the first switch groups in the remaining (N-1) switch channels are all set to the open state;

[0160] According to the first voltage value, the second voltage value and the N third voltage values obtained at the current time, the semiconductor switching devices in the N switch channels are diagnosed to obtain a switching device abnormality diagnosis result, including:

[0161] When the jth third voltage value corresponding to the jth switch channel, the remaining (N-1) third voltage values and the second voltage value are all the voltage drop values of the input potential point, it is determined that the switching device abnormality diagnosis result is that the first switch group in the jth switch channel has an abnormality;

[0162] When the jth third voltage value is equal to the first voltage value, and the second voltage value and the remaining (N-1) third voltage values are all the voltage drop values of the input potential point, it is determined that the switching device abnormality diagnosis result is that the second switch group in the jth switch channel has an abnormality;

[0163] When the jth third voltage value, the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the switching device abnormality diagnosis result is that all the semiconductor switching devices in the jth switch channel are normal, that is, all the semiconductor switching devices in the N switch channels are normal.

[0164] In the case that the first switch group in the jth switch channel is set to the open state, and the switch device abnormality diagnosis result is that none of the remaining (N-1) switch channels has an abnormality, the jth switch channel needs to be further diagnosed. In this case, based on the above situation, the first switch group in the jth switch channel is set to the closed state, and the first switch group in the remaining (N-1) switch channels is set to the open state.

[0165] Specifically, as shown in Figure 3 and Figure 5 When N=2, if the first switch group (Q5 and Q6) of the switch channel where VS3 is located is set to the open state, and the switch channel where VS4 is located is set to the closed state, it cannot be determined whether the switch channel where VS4 is located has an abnormality. At this time, the first switch group (Q5 and Q6) of the switch channel where VS3 is located is set to the closed state, that is, the switch channel where VS3 is located is closed, and the first switch group (Q9 and Q10) of the switch channel where VS4 is located is set to the open state.

[0166] If the voltage value of VS3, the voltage value of VS4, and the voltage drop voltage value of KL30 are all BAT+, and the first switch group of the switch channel where VS4 is located is in the open state, the potential of VS3 is the same as that of KL30, so it can be concluded that the first switch group (Q5 and Q6) of the switch channel where VS3 is located has a controlled closed abnormality or is significantly aged.

[0167] If the voltage value of VS3 is the voltage value of BAT+, and the voltage value of VS4 and the voltage value of KL30 are both the voltage drop voltage value of BAT+, it indicates that the potential of BAT+ is not the same as that of KL30, that is, the second switch group of the switch channel where VS3 is located is not conductive, so it can be concluded that the second switch group (Q7 and Q8) of the switch channel where VS3 is located has a controlled closed abnormality or is significantly aged.

[0168] If the voltage value of VS3, the voltage value of VS4, and the voltage value of KL30 are all the voltage value of BAT+, in combination with the above diagnosis scheme, it indicates that none of the semiconductor switch devices in the switch channel where VS3 is located has a controlled abnormality. In another embodiment of the present application, when the switch device abnormality diagnosis result is no diagnosis result, the second switch group in the kth switch channel of the N switch channels is set to the open state, and each of the remaining (N-1) switch channels is set to the closed state, where k is a natural number less than N.

[0169] Based on the first voltage value, the second voltage value, and the N third voltage values obtained at the current time, the semiconductor switch devices in the N switch channels are diagnosed to obtain a switch device abnormality diagnosis result, including:

[0170] when the kth third voltage value is equal to the first voltage value, and the second voltage value and the remaining (N-1) third voltage values are all voltage drop voltage values of the input potential point, it is determined that the abnormal diagnosis result of the switching device is that the first switch group in the remaining (N-1) switch channels is abnormal;

[0171] when the kth third voltage value and the remaining (N-1) third voltage values are all equal to the first voltage value, and the second voltage value is the voltage drop voltage value of the input potential point, it is determined that the abnormal diagnosis result of the switching device is that the second switch group in the remaining (N-1) switch channels is abnormal;

[0172] when the kth third voltage value, the remaining (N-1) third voltage values, and the second voltage value are all equal to the first voltage value, it is determined that the abnormal diagnosis result of the switching device is that part of the semiconductor switching devices in the remaining (N-1) switch channels are not controlled to be abnormal.

[0173] In view of the above, when the N switch channels are all in the closed state, i.e., the circuit breaker is in the closed state, the specific abnormality of the semiconductor devices in the N switch channels cannot be determined. Another way can be used to judge the abnormality. The second switch group in the kth switch channel of the N switch channels can be set to the open state, and the remaining switch channels can be set to the closed state. Here, k can be any natural number less than N. The third voltage value of the kth switch channel is used as a judgment reference, and it can be judged whether the first switch group and the second switch group in the N switch channels have abnormal conditions.

[0174] The above judgment method has the same principle as setting the first switch group in the jth switch channel of the N switch channels to the open state, and setting the other switch channels to the closed state to judge the abnormality of the N switch channels. Here, no additional examples are given. In another embodiment of the present application, when the abnormal diagnosis result of the switching device is that part of the semiconductor switching devices in the remaining (N-1) switch channels are not abnormal, the second switch group in the kth switch channel is set to the closed state, and the second switch group in the remaining (N-1) switch channels is set to the open state;

[0175] According to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time, the semiconductor switching devices in the N switch channels are diagnosed to obtain the switching device abnormal diagnosis result, including:

[0176] when the kth third voltage value and the second voltage value are both voltage drop voltage values of the input potential point, and the remaining (N-1) third voltage values are equal to the first voltage value, it is determined that the abnormal diagnosis result of the switching device is that the first switch group in the kth switch channel is abnormal;

[0177] when the kth third voltage value and the remaining (N-1) third voltage values are equal to the first voltage value, and the second voltage value is the voltage drop voltage value of the input potential point, it is determined that the switch device abnormality diagnosis result is that the second switch group of the kth switch channel exists abnormality;

[0178] when the kth third voltage value, the remaining (N-1) third voltage values, and the second voltage value are all equal to the first voltage value, it is determined that the switch device abnormality diagnosis result is that all semiconductor switch devices in the kth switch channel do not exist abnormality, i.e., all semiconductor switch devices in the N switch channels do not exist abnormality.

[0179] For the above-mentioned case that the second switch group in the kth switch channel in the N switch channels is set to an open state, and the switch device abnormality diagnosis result is that part of the semiconductor switch devices in the remaining (N-1) switch channels do not exist abnormality, further diagnosis needs to be performed on the kth switch channel. At this time, based on the above-mentioned case, the second switch group in the kth switch channel is set to a closed state, and the second switch groups in the remaining (N-1) switch channels are all set to an open state.

[0180] The above-mentioned judgment method and the method of setting the first switch group in the jth switch channel in the N switch channels to a closed state and setting the other switch channels to an open state to judge the abnormality of the N switch channels have the same principle, which will not be additionally exemplified here. In another embodiment of the present application, the switch device abnormality diagnosis result includes a short-circuit abnormality diagnosis result, when the first switch group and the second switch group in the mth switch channel in the N switch channels are both set to an open state, and the remaining (N-1) switch channels are all set to a closed state;

[0181] According to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time, the semiconductor switch devices in the N switch channels are diagnosed to obtain a switch device abnormality diagnosis result, including:

[0182] when the mth third voltage value corresponding to the mth switch channel is zero, and the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the short-circuit abnormality diagnosis result is that the mth switch channel does not exist short-circuit abnormality;

[0183] when the mth third voltage value, the remaining (N-1) third voltage values, and the second voltage value are all equal to the first voltage value, it is determined that the short-circuit abnormality diagnosis result is that the first switch group and the second switch group of the mth switch channel both exist short-circuit abnormality.

[0184] For the above case when N switch channels are in the closed state, i.e. the circuit breaker is in the closed state, it is not possible to determine the specific abnormality of the semiconductor devices in the N switch channels. Another way to determine whether there is a short circuit abnormality in the switch channel is to set the first switch group and the second switch group in the mth switch channel in the N switch channels to be in the open state, and set the remaining switch channels to be in the closed state. In the judgment process, the third voltage value of the mth switch channel is taken as the judgment reference, i.e. whether the first switch group and the second switch group in the N switch channels have a short circuit abnormality can be determined.

[0185] Specifically, when the mth third voltage value in the mth switch channel is zero, and the remaining (N-1) third voltage values and the second voltage value are equal to the first voltage value, it can be determined that the first switch group and the second switch group in the mth switch channel do not have a short circuit abnormality; when the mth third voltage value in the mth switch channel, the remaining (N-1) third voltage values and the second voltage value are equal to the first voltage value, it can be determined that there is a short circuit abnormality in the mth switch channel.

[0186] In this example, m can be any natural number less than N, so the above judgment method can be used to determine whether each switch channel in the N switch channels has a short circuit abnormality. The above content is summarized and described through a specific embodiment as follows: Figure 3 and Figure 5 As shown in FIGS. 1 and 2, the diagnostic logic of the MOSFET when the battery pack is in a discharging condition without external charging equipment charging the battery pack is specifically introduced. Taking a 12V battery pack for a vehicle as an example, this condition represents a condition in which the 12V power network charger stops charging the battery pack after the automobile is powered off, and the load on the 12V power network is completely powered by the battery pack.

[0187] Step 1: The controller sets all MOSFETs to be in the closed state, i.e. GS5, GS6, GS7 and GS8 are pulled to high level.

[0188] Step 2: Determine whether the KL30 voltage is greater than 0V and the battery pack discharge current is greater than 0A. If so, go to step 3. If not, it means that the MOSFET cannot be controlled to be closed or is significantly aged, showing a high impedance state. Fault alarm, exit diagnosis.

[0189] Step 3: Measure the voltage values of VS3 and VS4, and measure the battery module voltage BAT+.

[0190] Step 4: Make the following judgments:

[0191] If VS3 = BAT+ and VS4 = 0V, it means S7 & S8 cannot be controlled to close or are obviously aged, presenting a high impedance state. Fault alarm, exit diagnosis.

[0192] If VS3 = 0V and VS4 = BAT+, it means S5 & S6 cannot be controlled to close or are obviously aged, presenting a high impedance state, fault alarm, exit diagnosis.

[0193] If VS3 = BAT+ & VS4 = BAT+, go to Step 5.

[0194] Step 5: Turn off S5, i.e. input low level to GS5, collect KL30, VS3, VS4 voltages

[0195] Step 6: Judge:

[0196] If KL30 = VS3 = VS4 = BAT+ - 0.7V, S7 cannot be controlled to close or is obviously aged, presenting a high impedance state. Fault alarm, exit diagnosis.

[0197] If KL30 = VS3 = BAT+ - 0.7V and VS4 = BAT+, S8 cannot be controlled to close or is obviously aged, presenting a high impedance state. Fault alarm, exit diagnosis.

[0198] If KL30 = VS4 = BAT+ and BAT+ - 0.7 < VS3 < BAT+, turn on S5, turn off S7, go to Step 7.

[0199] Step 7: Measure KL30, VS3, VS4.

[0200] Step 8: Judge:

[0201] If VS3 = VS4 = KL30 = BAT+ - 0.7V, S5 cannot be controlled to close or is obviously aged, presenting a high impedance state. Fault alarm, exit diagnosis.

[0202] If KL30 = VS4 = BAT+ - 0.7V and VS3 = BAT+, S6 cannot be controlled to close or is obviously aged, presenting a high impedance state. Fault alarm, exit diagnosis.

[0203] If KL30 = VS3 = VS4 = BAT+, S5, S6, S7, S8 all do not exist the condition of being unable to be controlled to close.

[0204] Step 9: Exit the MOSFET unable to be controlled to close state diagnosis step, enter the MOSFET internal short circuit diagnosis step (unable to be controlled to open).

[0205] Step 10: disconnect S5 and S6, keep S7 and S8 closed, i.e. input low level to GS5 and GS6, input high level to GS7 and GS8. Collect VS3, VS4, BAT+ and KL30 voltage.

[0206] Judgment:

[0207] If VS3 = 0V, BAT+ = KL30 = VS4, S5 and S6 can be controlled to disconnect;

[0208] If VS3 = BAT+ = KL30 = VS4, it means that S5 or S6 or both have internal short circuit, which cannot be controlled to disconnect. Fault alarm, exit diagnosis.

[0209] Step 11: close S5 and S6, disconnect S7 and S8, i.e. input high level to GS5 and GS6, input low level to GS7 and GS8. Collect VS3, VS4, BAT+ and KL30 voltage. Judgment:

[0210] If VS4 = 0V, BAT+ = KL30 = VS3, S7 and S8 can be controlled to disconnect;

[0211] If VS4 = BAT+ = KL30 = VS3, it means that S7 or S8 or both have internal short circuit, which cannot be controlled to disconnect. Fault alarm, exit diagnosis.

[0212] Therefore, when checking the controlled abnormality and short circuit abnormality in the switch channel, the application can keep the circuit breaker in the on state by keeping at least one switch channel in the N switch channels in the closed state, when the circuit breaker is applied to the vehicle voltage power supply, it can ensure that the battery pack is always connected to the vehicle low-voltage power supply network, so as to diagnose the aging abnormality or uncontrolled abnormality of the semiconductor switch in the switch channel, so as to detect and diagnose the fault in time, and the safety is higher.

[0213] In another embodiment of the application, the application also provides a lithium battery system which adopts the circuit breaker abnormality diagnosis method.

[0214] The above describes in detail the circuit breaker, circuit breaker abnormality diagnosis method and lithium battery system provided by the embodiments of the application. The principles and implementation manners of the application are described by using specific examples. The above embodiment description is only used to help understand the method and core idea of the application. Meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation manner and application range can be changed. In summary, the content of the specification should not be understood as a limitation of the application.

Claims

1. A circuit breaker characterized by, The battery module end and the battery pack system end are coupled with N mutually parallel switch channels, the switch channels are composed of semiconductor switching devices, and the switch channels are used to control the on-off of the loop between the battery module end and the battery pack system end, wherein N is a natural number greater than or equal to 2. The switch channels include: The first switch group is coupled with the battery module end; The second switch group is coupled with the first switch group and the battery pack system end; The coupling points between the first switch group and the second switch group form channel potential points, the first switch group and the battery module end form input potential points, and the second switch group and the battery pack system end form output potential points; When diagnosing the N switch channels, at least one of the N switch channels is in a closed state to keep the circuit breaker in a conductive state; At least one of the N switch channels is set to a closed state, the first voltage value of the input potential point, the second voltage value of the output potential point, and the third voltage value of the N channel potential points corresponding to the N switch channels are obtained at the current time, the semiconductor switching devices in the N switch channels are diagnosed according to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time, and a switching device abnormal diagnosis result is obtained; The switching device abnormal diagnosis result includes a controlled abnormal diagnosis result when each of the N switch channels is set to a closed state; The diagnosis of the semiconductor switching devices in the N switch channels according to the first voltage value, the second voltage value, and the N third voltage values obtained at the current time to obtain the switching device abnormal diagnosis result includes: When the second voltage value does not change, it is determined that all semiconductor switching devices in the N switch channels have controlled abnormalities; When the third voltage value corresponding to the i-th switch channel is zero, and the third voltage values corresponding to the remaining (N-1) switch channels are equal to the first voltage value, it is determined that part of the semiconductor switching devices in the i-th switch channel have controlled abnormalities, wherein i is a natural number less than N; When the N third voltage values corresponding to the N switch channels are equal to the first voltage value, it is determined that there is no diagnosis result for the controlled abnormal diagnosis result; When the switching device abnormal diagnosis result is no diagnosis result, the first switch group in the j-th switch channel of the N switch channels is set to an open state, and the remaining (N-1) switch channels are set to a closed state, wherein j is a natural number less than N. ​ ​ The first voltage value, the second voltage value and N third voltage values obtained according to the current time are used to diagnose the semiconductor switching devices in the N switching channels, and a switching device abnormality diagnosis result is obtained, comprising: When the jth third voltage value corresponding to the jth switching channel, the remaining (N-1) third voltage values and the second voltage value are all voltage drop values of the input potential point, it is determined that the controlled abnormality diagnosis result is that the first switching group in the remaining (N-1) switching channels all have controlled abnormality; When the jth third voltage value and the second voltage value are both voltage drop values of the input potential point, and the remaining (N-1) third voltage values are all equal to the first voltage value, it is determined that the controlled abnormality diagnosis result is that the second switching group in the remaining (N-1) switching channels all have controlled abnormality; When the jth third voltage value is greater than the voltage drop value of the input potential point and less than the first voltage value, and the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the controlled abnormality diagnosis result is that all semiconductor switching devices of the remaining (N-1) switching channels do not have controlled abnormality.

2. The circuit breaker of claim 1, wherein The circuit breaker comprises a driving module, and the driving module comprises a first driving pin and a second driving pin; The first switching group comprises a first switching tube, and the first switching tube comprises a first control electrode coupled with the first driving pin; The second switching group comprises a second switching tube, and the second switching tube comprises a second control electrode coupled with the second driving pin.

3. The circuit breaker of claim 2, wherein, The channel potential point comprises a first channel potential point, the input potential point comprises a first input potential point, and the output potential point comprises a first output potential point; The first switching tube comprises a first main voltage pole and a first auxiliary voltage pole, and the second switching tube comprises a second main voltage pole and a second auxiliary voltage pole; The first main voltage pole of the first switching tube is coupled with the second main voltage pole of the second switching tube, and the first main voltage pole and the second main voltage pole form the first channel potential point; The first auxiliary voltage pole of the first switching tube is coupled with the battery module end, and the first auxiliary voltage pole and the battery module end form the first input potential point; The second auxiliary voltage pole of the second switching tube is coupled with the battery pack system end, and the second auxiliary voltage pole and the battery pack system end form the first output potential point.

4. The circuit breaker of claim 2, wherein, The driving module comprises a third driving pin and a fourth driving pin; The first switching group comprises a plurality of third switching tubes, and each third switching tube comprises a third control electrode coupled with the third driving pin; The second switching group comprises a plurality of fourth switching tubes, and each fourth switching tube comprises a fourth control electrode coupled with the fourth driving pin.

5. The circuit breaker of claim 4, wherein, The channel potential point comprises a plurality of second channel potential points, the input potential point comprises a second input potential point, and the output potential point comprises a second output potential point; The third switch tube comprises a third main voltage pole and a third auxiliary voltage pole, and the fourth switch tube comprises a fourth main voltage pole and a fourth auxiliary voltage pole; The third main voltage poles of the plurality of third switch tubes are respectively coupled with the fourth main voltage poles of the plurality of fourth switch tubes, and the plurality of connection points formed between the plurality of third main voltage poles and the plurality of fourth main voltage poles are all the second channel potential points, and the plurality of connection points are all coupled through wires; The third auxiliary voltage poles of the plurality of third switch tubes are all coupled with the battery module end, and the third auxiliary voltage poles and the battery module end form the second input potential point; The fourth auxiliary voltage poles of the plurality of fourth switch tubes are all coupled with the battery pack system end, and the fourth auxiliary voltage poles and the battery pack system end form the second output potential point.

6. The circuit breaker of claim 1, wherein, A sampling resistor is coupled between the battery module end and the battery pack system end.

7. A circuit breaker abnormality diagnosing method characterized by comprising: The circuit breaker abnormality diagnosis method is applied to the circuit breaker as claimed in any one of claims 1 to 6, and the circuit breaker abnormality diagnosis method comprises: At least one of the N switch channels is set to a closed state; A first voltage value of the input potential point, a second voltage value of the output potential point, and N third voltage values of N channel potential points corresponding to the N switch channels are acquired at the current time; According to the first voltage value, the second voltage value, and the N third voltage values acquired at the current time, semiconductor switch devices in the N switch channels are diagnosed to obtain a switch device abnormality diagnosis result.

8. The circuit breaker abnormality diagnosing method according to claim 7, characterized by, When the switch device abnormality diagnosis result is that all semiconductor switch devices in the remaining (N-1) switch channels do not exist controlled abnormality, a first switch group in the jth switch channel is set to a closed state, and the first switch group in the remaining (N-1) switch channels is set to an open state; According to the first voltage value, the second voltage value, and the N third voltage values acquired at the current time, semiconductor switch devices in the N switch channels are diagnosed to obtain a switch device abnormality diagnosis result, comprising: When the jth third voltage value corresponding to the jth switch channel, the remaining (N-1) third voltage values, and the second voltage value are all voltage drop values of the input potential point, it is determined that the controlled abnormality diagnosis result is that the first switch group in the jth switch channel exists controlled abnormality; When the jth third voltage value is equal to the first voltage value, and the second voltage value and the remaining (N-1) third voltage values are all voltage drop values of the input potential point, it is determined that the controlled abnormality diagnosis result is that the second switch group in the jth switch channel exists controlled abnormality; determining that the controlled abnormality diagnosis result is that all semiconductor switching devices in the jth switching channel do not have controlled abnormality, i.e., all semiconductor switching devices in the N switching channels do not have controlled abnormality.

9. The circuit breaker abnormality diagnosing method according to claim 7, wherein when the controlled abnormality diagnosis result is that no diagnosis result is obtained, setting the second switching group in the kth switching channel of the N switching channels to an open state, and setting each of the remaining (N-1) switching channels to a closed state, wherein k is a natural number less than N; the first voltage value, the second voltage value and the N third voltage values obtained at the current moment, diagnosing semiconductor switching devices in the N switching channels to obtain a switching device abnormality diagnosis result, comprising: when the kth third voltage value corresponding to the kth switching channel and the second voltage value are both voltage drop values of the input potential point, and the remaining (N-1) third voltage values are equal to the first voltage value, it is determined that the controlled abnormality diagnosis result is that the first switching group of the kth switching channel has controlled abnormality; when the kth third voltage value and the remaining (N-1) third voltage values are both equal to the first voltage value, and the second voltage value is the voltage drop value of the input potential point, it is determined that the controlled abnormality diagnosis result is that the second switching group of the kth switching channel has controlled abnormality; when the kth third voltage value, the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the controlled abnormality diagnosis result is that part of the semiconductor switching devices of the remaining (N-1) switching channels do not have controlled abnormality.

10. The circuit breaker abnormality diagnosing method according to claim 9, wherein when the controlled abnormality diagnosis result is that part of the semiconductor switching devices of the remaining (N-1) switching channels do not have controlled abnormality, setting the second switching group in the kth switching channel to a closed state, and setting the second switching group in the remaining (N-1) switching channels to an open state; the first voltage value, the second voltage value and the N third voltage values obtained at the current moment, diagnosing semiconductor switching devices in the N switching channels to obtain a switching device abnormality diagnosis result, comprising: when the kth third voltage value corresponding to the kth switching channel and the second voltage value are both voltage drop values of the input potential point, and the remaining (N-1) third voltage values are equal to the first voltage value, it is determined that the controlled abnormality diagnosis result is that the first switching group of the kth switching channel has controlled abnormality; when the kth third voltage value and the remaining (N-1) third voltage values are both equal to the first voltage value, and the second voltage value is the voltage drop value of the input potential point, it is determined that the controlled abnormality diagnosis result is that the second switching group of the kth switching channel has controlled abnormality; When the kth third voltage value, the remaining (N-1) third voltage values and the second voltage value are equal to the first voltage value, it is determined that the controlled abnormality diagnosis result is that all semiconductor switching devices of the kth switching channel do not have controlled abnormality, i.e., all semiconductor switching devices in the N switching channels do not have controlled abnormality.

11. The circuit breaker abnormality diagnosing method according to claim 9, wherein The switching device abnormality diagnosis result includes a short-circuit abnormality diagnosis result, when the first switching group and the second switching group in the mth switching channel of the N switching channels are both set to an open state, and the remaining (N-1) switching channels are all set to a closed state; The switching device abnormality diagnosis result includes a short-circuit abnormality diagnosis result, when the first switching group and the second switching group in the mth switching channel of the N switching channels are both set to an open state, and the remaining (N-1) switching channels are all set to a closed state; The switching device abnormality diagnosis result includes a short-circuit abnormality diagnosis result, when the first switching group and the second switching group in the mth switching channel of the N switching channels are both set to an open state, and the remaining (N-1) switching channels are all set to a closed state; When the mth third voltage value corresponding to the mth switching channel is zero, and the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the short-circuit abnormality diagnosis result is that the mth switching channel does not have short-circuit abnormality.

12. A lithium battery system characterized by, When the mth third voltage value, the remaining (N-1) third voltage values and the second voltage value are all equal to the first voltage value, it is determined that the short-circuit abnormality diagnosis result is that the first switching group and the second switching group of the mth switching channel both have short-circuit abnormality. The lithium battery system adopts the circuit breaker abnormality diagnosis method according to any one of claims 7 to 11.

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