Method and apparatus for detecting a battery system

Abstract

The application provides a detection method and device for a battery system, which can optimize circuit design. The device comprises a switching unit and a processing unit. The switching unit comprises a plurality of switching branches and a plurality of switching switches. Each of the plurality of switching branches comprises a switching resistor. The plurality of switching switches are used to control the plurality of switching branches to cut in or cut out the following terminals from the reference ground: the positive electrode of the battery pack, the second end of the first contactor, the negative electrode of the battery pack, and the second end of the second contactor. The reference ground is used to connect the vehicle body ground. The processing unit is used to detect sampling point voltage information of the plurality of switching branches, wherein the sampling point voltage information is used to indicate the sampling point voltage of the plurality of switching branches; and determine high-voltage detection information and insulation detection information according to the sampling point voltage information.

Description

Technical Field

[0001] This application relates to the field of batteries, and more particularly to testing methods and apparatus for battery systems. Background Technology

[0002] Currently, the DC voltage of high-voltage battery systems used in electric or hybrid vehicles far exceeds the safe voltage for humans. For example, the DC voltage range of high-voltage battery systems is typically 200V-800V, while the safe voltage for humans is 60V. Therefore, for safety reasons, high-voltage testing and insulation testing of the battery system are necessary. High-voltage testing refers to testing the battery pack voltage and load voltage in the high-voltage battery system, while insulation testing refers to testing the insulation resistance to ground of the two terminals of the battery pack in the high-voltage battery system.

[0003] However, in traditional solutions for testing high-voltage battery systems, high-voltage testing and insulation testing require electrical isolation. Therefore, they are usually designed as two independent circuits, which are complex and occupy a large circuit area. Summary of the Invention

[0004] This application provides a detection method and apparatus for a battery system, which can optimize circuit design.

[0005] In a first aspect, a detection device for a battery system is provided, the battery system comprising: a battery pack, a first contactor, and a second contactor, wherein a first end of the first contactor is connected to the positive terminal of the battery pack, a first end of the second contactor is connected to the negative terminal of the battery pack, a second end of the first contactor is used to connect to a first terminal of a load, and a second end of the second contactor is used to connect to a second terminal of the load. The detection device comprises: a switching unit including a plurality of switching branches and a plurality of switching switches, each of the plurality of switching branches including a switching resistor, the plurality of switching switches being used to control the plurality of switching branches to switch into or out of a plurality of terminals and a reference ground: the positive terminal of the battery pack, the second end of the first contactor, the negative terminal of the battery pack, and the second end of the second contactor, wherein the reference ground is used to connect to the vehicle body ground; and a processing unit for: detecting sampling point voltage information of the plurality of switching branches, the sampling point voltage information being used to indicate the sampling point voltage of the plurality of switching branches; and determining high-voltage detection information and insulation detection information based on the sampling point voltage information, wherein the high-voltage detection information includes at least one of the following: battery pack voltage U. bat and load voltage U load The insulation detection information includes at least one of the following: the insulation resistance value R of the positive terminal of the battery pack to ground. p The insulation resistance value R of the negative terminal of the battery pack to ground n .

[0006] The battery system testing device includes a switching unit. Multiple switching branches within this unit can flexibly connect or disconnect between multiple terminals in the battery system and the reference ground. Utilizing these multiple switching branches, the testing device 200 can detect the sampling point voltages of these branches under different conditions, thereby achieving high-voltage and insulation testing of the battery system. Since the reference grounds of the multiple switching branches in the switching unit are all connected to the vehicle body ground, the testing device does not require electrical isolation for high-voltage and insulation testing. A single circuit can be used to achieve both high-voltage and insulation testing of the battery system, optimizing circuit design and improving the efficiency of battery system testing.

[0007] In conjunction with the first aspect, in one possible implementation, the processing unit is further configured to determine at least one of the following information based on the sampling point voltage information: contact status information of the first contactor and contact status information of the second contactor, wherein the contact status information is used to indicate whether the contacts of the contactor are stuck together.

[0008] In addition to high-voltage and insulation testing, the testing device can also detect contact adhesion of the battery system's contactors using the same circuit, thereby further optimizing the circuit design.

[0009] In conjunction with the first aspect, in one possible implementation, the switching unit further includes a plurality of sampling branches, the first end of each of the plurality of sampling branches being connected to the second end of at least one of the plurality of switching branches, and the second end of each of the plurality of sampling branches being connected to the reference ground.

[0010] By utilizing multiple sampling branches, the sampling point voltages of multiple switching branches can be collected, and these multiple sampling branches can be reused in high voltage detection, insulation detection, and contact adhesion detection, thereby optimizing the circuit design.

[0011] In conjunction with the first aspect, in one possible implementation, each of the plurality of sampling branches includes an upsampling resistor and a downsampling resistor, a first terminal of the upsampling resistor is connected to a first terminal of each sampling branch, a second terminal of the upsampling resistor is connected to a first terminal of the downsampling resistor, and a second terminal of the downsampling resistor is connected to the reference ground, wherein the sampling point voltage of the switching branch is the voltage at the second terminal of the upsampling resistor.

[0012] In conjunction with the first aspect, in one possible implementation, the plurality of switching branches include a first switching branch to a fourth switching branch, and the plurality of switching switches include a first switching switch to a fourth switching switch. The first switching branch includes a first switching resistor, and the first switching switch controls whether the first switching branch switches in or out between the positive terminal of the battery pack and the reference ground. The second switching branch includes a second switching resistor, and the second switching switch controls whether the second switching branch switches in or out between the negative terminal of the battery pack and the reference ground. The third switching branch includes a third switching resistor, and the third switching switch controls whether the third switching branch switches in or out between the second terminal of the first contactor and the reference ground. The fourth switching branch includes a fourth switching resistor, and the fourth switching switch controls whether the fourth switching branch switches in or out between the second terminal of the second contactor and the reference ground.

[0013] By utilizing multiple switching switches and multiple switching branches, it is possible to flexibly control the multiple switching branches to switch in or out between various terminals and reference ground in the battery system for different detection scenarios such as high voltage detection, insulation detection, or contact adhesion detection. The aforementioned multiple switching switches and multiple switching branches can be reused in different detection scenarios, thereby achieving the purpose of simplifying and optimizing circuit design.

[0014] In conjunction with the first aspect, in one possible implementation, the plurality of sampling branches include a first sampling branch and a second sampling branch, wherein a first end of the first sampling branch is connected to a second end of the first switching branch and a second end of the third switching branch; and a second end of the second sampling branch is connected to a second end of the second switching branch and a second end of the fourth switching branch.

[0015] By using switching control, the voltage of the sampling points of four switching branches can be collected using two sampling branches, thereby improving the utilization rate of the sampling branches and simplifying the circuit design.

[0016] In conjunction with the first aspect, in one possible implementation, the processing unit is specifically configured to: control the plurality of switching switches to a first operating state, wherein the first operating state is: the first switching switch and the second switching switch are turned on, and the third switching switch and the fourth switching switch are turned off; when the plurality of switching switches are in the first operating state, detect the first sampling point voltage U1 of the first switching branch and the second sampling point voltage U2 of the second switching branch; and determine the battery pack voltage U based on the first sampling point voltage U1 and the second sampling point voltage U2. bat .

[0017] The processing unit controls the on / off state of the switching switch and collects the voltage at corresponding sampling points for calculation. This detection device can be used to detect the battery pack voltage U of the battery system. bat .

[0018] In conjunction with the first aspect, in one possible implementation, the processing unit is specifically configured to determine the battery pack voltage U according to the following formula. bat :

[0019] U bat =U p -U n ;

[0020] U p =U1×(R1+R 11 +R 12 ) / R 12 ;

[0021] U n =U2×(R2+R 21 +R 22 )R 22 ;

[0022] Among them, U p U represents the positive voltage of the battery pack. n R1 represents the negative terminal voltage of the battery pack, R2 represents the resistance value of the first switching resistor, and R3 represents the resistance value of the second switching resistor. 11 R represents the resistance value of the upsampling resistor in the first sampling branch. 12 R represents the resistance value of the downsampling resistor in the first sampling branch. 21 R represents the resistance value of the upsampling resistor in the second sampling branch. 22 This indicates the resistance value of the downsampling resistor in the second sampling branch.

[0023] In conjunction with the first aspect, in one possible implementation, the processing unit is specifically configured to: control the plurality of switching switches, the first contactor, and the second contactor to be in a second operating state, wherein the second operating state is: the first switching switch and the second switching switch are open, the third switching switch and the fourth switching switch are on, and the first contactor and the second contactor are open; when the plurality of switching switches, the first contactor, and the second contactor are in the second operating state, detect the third sampling point voltage U3 of the third switching branch and the fourth sampling point voltage U4 of the fourth switching branch; and determine the load voltage U based on the third sampling point voltage U3 and the fourth sampling point voltage U4. load .

[0024] The processing unit controls the on / off state of the switching switch and contactor, and collects the voltage at the corresponding sampling points for calculation. This detection device can then be used to detect the load voltage U of the battery system. load This improves the detection efficiency of the battery system.

[0025] In conjunction with the first aspect, in one possible implementation, the processing unit is specifically configured to determine the load voltage U according to the following formula. load :

[0026] U load =U p '-U n ';

[0027] U p =U3×(R3+R 11 +R 12 ) / R 12 ;

[0028] U n =U4×(R4+R 21 +R 22 )R 12 ;

[0029] Among them, U p ' represents the first terminal voltage of the load, U n ' represents the second terminal voltage of the load, R3 represents the resistance value of the third switching resistor, R4 represents the resistance value of the fourth switching resistor, R 11 R represents the resistance value of the upsampling resistor in the first sampling branch. 12 R represents the resistance value of the downsampling resistor in the first sampling branch. 21 R represents the resistance value of the upsampling resistor in the second sampling branch. 22 This indicates the resistance value of the downsampling resistor in the second sampling branch.

[0030] In conjunction with the first aspect, in one possible implementation, the processing unit is specifically configured to: control the plurality of switching switches to a first operating state, wherein the first operating state is: the first switching switch and the second switching switch are turned on, and the third switching switch and the fourth switching switch are turned off; when the plurality of switching switches are in the first operating state, detect the first sampling point voltage U1 of the first switching branch and the second sampling point voltage U2 of the second switching branch; and control the plurality of switching switches to a third operating state, wherein the first switching switch is turned on, and the second switching switch to the fourth switching switch are turned off; when the plurality of switching switches are in the third operating state, detect the fifth sampling point voltage U5 of the first switching branch; and determine the positive terminal-to-ground insulation resistance value R of the battery pack based on the first sampling point voltage U1, the second sampling point voltage U2, and the fifth sampling point voltage U5. p The insulation resistance value R of the negative terminal of the battery pack to ground n .

[0031] The processing unit controls the on / off state of the switching switch and collects the voltage at the corresponding sampling points for calculation. This detection device can be used to perform insulation testing on the battery system, thereby improving the detection efficiency of the battery system.

[0032] In conjunction with the first aspect, in one possible implementation, the processing unit is specifically configured to determine the positive-to-ground insulation resistance value R of the battery pack according to the following formula. p The insulation resistance value R of the negative terminal of the battery pack to ground n :

[0033] U p1 / (R p / / (R1+R 11 +R 12 ))=-U n1 / (R n / / (R2+R 21 +R 22 ));

[0034] U p2 / (R p / / (R1+R 11 +R 12 ))=-U n2 / R n ;

[0035] U p1 =U1×(R1+R 11 +R 12 ) / R 12 ;

[0036] Un1 =U2×(R2+R 21 +R 22 ) / R 22 ;

[0037] U p2 =U5×(R1+R 11 +R 12 ) / R 12 ;

[0038] U n2 =U n1 -U p1 +U p2 ;

[0039] Among them, U p1 U represents the positive voltage of the battery pack in the first operating state. n1 U represents the negative electrode voltage of the battery pack in the first operating state. p2 U represents the positive voltage of the battery pack in the third operating state. n2 R represents the negative terminal voltage of the battery pack in the third operating state, R1 represents the resistance value of the first switching resistor, R2 represents the resistance value of the second switching resistor, and R... 11 R represents the resistance value of the upsampling resistor in the first sampling branch. 12 R represents the resistance value of the downsampling resistor in the first sampling branch. 21 R represents the resistance value of the upsampling resistor in the second sampling branch. 22 This indicates the resistance value of the downsampling resistor in the second sampling branch.

[0040] In conjunction with the first aspect, in one possible implementation, the processing unit is further configured to: control the first switching switch to turn on, and acquire the voltage U at the first terminal of the first contactor. c1 The third switching switch is turned on, and the voltage U at the second terminal of the first contactor is obtained. c2 According to U c1 and U c2 The actual working state of the first contactor is determined; the indicated working state of the first contactor is obtained, wherein the indicated working state is the working state of the first contactor indicated by the contactor control signal; and the contact state information of the first contactor is obtained based on whether the actual working state and the indicated working state are consistent.

[0041] The processing unit controls the on / off state of the switching switch and collects the voltage at the corresponding sampling points for calculation. This detection device can be used to detect contactor adhesion in the battery system, thereby improving the detection efficiency of the battery system.

[0042] In conjunction with the first aspect, in one possible implementation, the battery system includes N battery packs, the battery pack being the first of the N battery packs. The battery system also includes a third contactor to a 3(N-1)th contactor, where N ≥ 2. Specifically, the positive terminal of the i-th battery pack is connected to the first end of the (3(N-3)th)th contactor, the second end of the (3(N-3)th)th contactor is used to connect to the first end of the load, the negative terminal of the i-th battery pack is connected to the first end of the (3(N-2)th)th contactor, the second end of the (3(N-2)th)th contactor is connected to the second end of the load, and the positive terminal of the i-th battery pack is connected to the (i-1)th battery pack. A 3i-1th contactor is provided between the negative terminals of the pack, where 2≤i≤N; the plurality of switching switches also include a fifth switching switch to a 2N+2nd switching switch, and the plurality of switching branches also include a fifth switching branch to a 2N+2nd switching branch, wherein the 2i+1th switching branch includes a 2i+1th switching resistor, and the 2i+1th switching switch is used to control the 2i+1th switching branch to switch in or out between the positive terminal of the i-th battery pack and the reference ground; the 2i+2th switching branch includes a 2i+2th switching resistor, and the 2i+2th switching switch is used to control the 2i+2th switching branch to switch in or out between the negative terminal of the i-th battery pack and the reference ground.

[0043] The switching branch in the switching unit of the battery system detection device can be expanded based on the number of battery packs and the connection method in the battery system to be tested. This allows for the use of a single circuit to achieve high-voltage detection and insulation detection of a battery system including multiple battery packs, thereby optimizing circuit design and improving circuit detection efficiency.

[0044] In conjunction with the first aspect, in one possible implementation, the plurality of sampling branches include a first sampling branch and a second sampling branch, wherein a first end of the first sampling branch is connected to a second end of the (2i+1)th switching branch; and a first end of the second sampling branch is connected to a second end of the (2i+2)th switching branch.

[0045] Secondly, a detection method for a battery system is provided. The battery system includes a battery pack, a first contactor, and a second contactor. A first terminal of the first contactor is connected to the positive terminal of the battery pack, and a first terminal of the second contactor is connected to the negative terminal of the battery pack. A second terminal of the first contactor is used to connect to a first terminal of a load, and a second terminal of the second contactor is used to connect to a second terminal of the load. The method is executed by a detection device, which includes a switching unit and a processing unit. The processing unit includes multiple switching branches and multiple switching switches. Each of the multiple switching branches includes a switching resistor. The plurality of switching switches are used to control the plurality of switching branches to switch into or out of the following plurality of terminals and reference ground: the positive terminal of the battery pack, the second terminal of the first contactor, the negative terminal of the battery pack, and the second terminal of the second contactor, wherein the reference ground is used to connect to the vehicle body ground; the method includes: the processing unit detecting sampling point voltage information of the plurality of switching branches, the sampling point voltage information being used to indicate the sampling point voltage of the plurality of switching branches; the processing unit determining high voltage detection information and insulation detection information based on the sampling point voltage information, wherein the high voltage detection information includes at least one of the following: battery pack voltage U bat and load voltage U load The insulation detection information includes at least one of the following: the insulation resistance value R of the positive terminal of the battery pack to ground. p The insulation resistance value R of the negative terminal of the battery pack to ground n .

[0046] The battery system testing device includes a switching unit. Multiple switching branches within this unit can flexibly connect or disconnect between multiple terminals in the battery system and the reference ground. Utilizing these multiple switching branches, the testing device 200 can detect the sampling point voltages of these branches under different conditions, thereby achieving high-voltage and insulation testing of the battery system. Since the reference grounds of the multiple switching branches in the switching unit are all connected to the vehicle body ground, the testing device does not require electrical isolation for high-voltage and insulation testing. A single circuit can be used to achieve both high-voltage and insulation testing of the battery system, optimizing circuit design and improving the efficiency of battery system testing.

[0047] In conjunction with the second aspect, in one possible implementation, the method further includes: the processing unit determining at least one of the following information based on the sampling point voltage information: contact status information of the first contactor and contact status information of the second contactor, wherein the contact status information is used to indicate whether the contacts of the contactor are stuck together.

[0048] In conjunction with the second aspect, in one possible implementation, the switching unit further includes a plurality of sampling branches, the first end of each of the plurality of sampling branches being connected to the second end of at least one of the plurality of switching branches, and the second end of each of the plurality of sampling branches being connected to the reference ground.

[0049] In conjunction with the second aspect, in one possible implementation, each of the plurality of sampling branches includes an upsampling resistor and a downsampling resistor. The first end of the upsampling resistor is connected to the first end of each sampling branch, the second end of the upsampling resistor is connected to the first end of the downsampling resistor, and the second end of the downsampling resistor is connected to the reference ground. The sampling point voltage of the switching branch is the voltage at the second end of the upsampling resistor.

[0050] In conjunction with the second aspect, in one possible implementation, the plurality of switching branches include a first switching branch to a fourth switching branch, and the plurality of switching switches include a first switching switch to a fourth switching switch. The first switching branch includes a first switching resistor, and the first switching switch controls whether the first switching branch switches in or out between the positive terminal of the battery pack and the reference ground. The second switching branch includes a second switching resistor, and the second switching switch controls whether the second switching branch switches in or out between the negative terminal of the battery pack and the reference ground. The third switching branch includes a third switching resistor, and the third switching switch controls whether the third switching branch switches in or out between the second terminal of the first contactor and the reference ground. The fourth switching branch includes a fourth switching resistor, and the fourth switching switch controls whether the fourth switching branch switches in or out between the second terminal of the second contactor and the reference ground.

[0051] In conjunction with the second aspect, in one possible implementation, the plurality of sampling branches include a first sampling branch and a second sampling branch, wherein a first end of the first sampling branch is connected to a second end of the first switching branch and a second end of the third switching branch; and a second end of the second sampling branch is connected to a second end of the second switching branch and a second end of the fourth switching branch.

[0052] In conjunction with the second aspect, in one possible implementation, the processing unit determines high-voltage detection information and insulation detection information based on the sampling point voltage information, including: the processing unit controlling the plurality of switching switches to be in a first operating state, wherein the first operating state is: the first switching switch and the second switching switch are on, and the third switching switch and the fourth switching switch are off; the processing unit, while the plurality of switching switches are in the first operating state, detects the first sampling point voltage U1 of the first switching branch and the second sampling point voltage U2 of the second switching branch; and the processing unit determines the battery pack voltage U based on the first sampling point voltage U1 and the second sampling point voltage U2. bat .

[0053] In conjunction with the second aspect, in one possible implementation, the processing unit determines the battery pack voltage U based on the first sampling point voltage U1 and the second sampling point voltage U2. bat The processing unit determines the battery pack voltage U according to the following formula. bat :

[0054] U bat =U p -U n ;

[0055] U p =U1×(R1+R 11 +R 12 ) / R 12 ;

[0056] U n =U2×(R2+R 21 +R 22 )R 22 ;

[0057] Among them, U p U represents the positive voltage of the battery pack. n R1 represents the negative terminal voltage of the battery pack, R2 represents the resistance value of the first switching resistor, and R3 represents the resistance value of the second switching resistor. 11 R represents the resistance value of the upsampling resistor in the first sampling branch. 12 R represents the resistance value of the downsampling resistor in the first sampling branch. 21 R represents the resistance value of the upsampling resistor in the second sampling branch. 22 This indicates the resistance value of the downsampling resistor in the second sampling branch.

[0058] In conjunction with the second aspect, in one possible implementation, the processing unit determines high-voltage detection information and insulation detection information based on the sampling point voltage information, including: the processing unit controls the plurality of switching switches, the first contactor, and the second contactor to be in a second operating state, wherein the second operating state is: the first switching switch and the second switching switch are open, the third switching switch and the fourth switching switch are on, and the first contactor and the second contactor are open; when the plurality of switching switches, the first contactor, and the second contactor are in the second operating state, the processing unit detects the third sampling point voltage U3 of the third switching branch and the fourth sampling point voltage U4 of the fourth switching branch; and the processing unit determines the load voltage U based on the third sampling point voltage U3 and the fourth sampling point voltage U4. load .

[0059] In conjunction with the second aspect, in one possible implementation, the processing unit determines the load voltage U based on the third sampling point voltage U3 and the fourth sampling point voltage U4. load The processing unit determines the load voltage U according to the following formula. load :

[0060] U load =U p '-U n ';

[0061] U p =U3×(R3+R 11 +R 12 ) / R 12 ;

[0062] U n =U4×(R4+R 21 +R 22 )R 12 ;

[0063] Among them, U p ' represents the first terminal voltage of the load, U n ' represents the second terminal voltage of the load, R3 represents the resistance value of the third switching resistor, R4 represents the resistance value of the fourth switching resistor, R 11 R represents the resistance value of the upsampling resistor in the first sampling branch. 12 R represents the resistance value of the downsampling resistor in the first sampling branch. 21 R represents the resistance value of the upsampling resistor in the second sampling branch. 22 This indicates the resistance value of the downsampling resistor in the second sampling branch.

[0064] In conjunction with the second aspect, in one possible implementation, the processing unit determines high-voltage detection information and insulation detection information based on the sampling point voltage information, including: the processing unit controlling the plurality of switching switches to be in a first operating state, wherein the first switching switch and the second switching switch are on, and the third switching switch and the fourth switching switch are off; the processing unit detecting the first sampling point voltage U1 of the first switching branch and the second sampling point voltage U2 of the second switching branch when the plurality of switching switches are in the first operating state; and the processing unit controlling the plurality of switching switches to be in a third operating state, wherein the first switching switch is on, and the second switching switch to the fourth switching switch are off; the processing unit detecting the fifth sampling point voltage U5 of the first switching branch when the plurality of switching switches are in the third operating state; and the processing unit determining the positive terminal-to-ground insulation resistance value R of the battery pack based on the first sampling point voltage U1, the second sampling point voltage U2, and the fifth sampling point voltage U5. p The insulation resistance value R of the negative terminal of the battery pack to ground n .

[0065] In conjunction with the second aspect, in one possible implementation, the processing unit determines the positive terminal-to-ground insulation resistance value R of the battery pack based on the first sampling point voltage U1, the second sampling point voltage U2, and the fifth sampling point voltage U5. p The insulation resistance value R of the negative terminal of the battery pack to ground n The processing unit determines the positive-to-ground insulation resistance value R of the battery pack according to the following formula. p The insulation resistance value R of the negative terminal of the battery pack to ground n :

[0066] U p1 / (R p / / (R1+R 11 +R 12 ))=-U n1 / (R n / / (R2+R 21 +R 22 ));

[0067] U p2 / (R p / / (R1+R 11 +R 12 ))=-U n2 / R n ;

[0068] U p1 =U1×(R1+R11 +R 12 ) / R 12 ;

[0069] U n1 =U2×(R2+R 21 +R 22 ) / R 22 ;

[0070] U p2 =U5×(R1+R 11 +R 12 ) / R 12 ;

[0071] U n2 =U n1 -U p1 +U p2 ;

[0072] Among them, U p1 U represents the positive voltage of the battery pack in the first operating state. n1 U represents the negative electrode voltage of the battery pack in the first operating state. p2 U represents the positive voltage of the battery pack in the third operating state. n2 R represents the negative terminal voltage of the battery pack in the third operating state, R1 represents the resistance value of the first switching resistor, R2 represents the resistance value of the second switching resistor, and R... 11 R represents the resistance value of the upsampling resistor in the first sampling branch. 12 R represents the resistance value of the downsampling resistor in the first sampling branch. 21 R represents the resistance value of the upsampling resistor in the second sampling branch. 22 This indicates the resistance value of the downsampling resistor in the second sampling branch.

[0073] In conjunction with the second aspect, in one possible implementation, the method further includes: the processing unit controlling the first switching switch to turn on, and acquiring the voltage U at the first terminal of the first contactor. c1 The processing unit controls the third switching switch to turn on and acquires the voltage U at the second terminal of the first contactor. c2 The processing unit according to U c1 and U c2 The processing unit determines the actual working state of the first contactor; the processing unit obtains the indicated working state of the first contactor, which is the working state of the first contactor indicated by the contactor control signal; the processing unit obtains the contact state information of the first contactor based on whether the actual working state and the indicated working state are consistent.

[0074] In conjunction with the second aspect, in one possible implementation, the battery system includes N battery packs, with the battery pack being the first of the N battery packs. The battery system also includes a third contactor to a third (3N-1)th contactor, where N ≥ 2. Specifically, the positive terminal of the i-th battery pack is connected to the first end of the (3i-3)th contactor, the second end of the (3i-3)th contactor is used to connect to the first end of the load, the negative terminal of the i-th battery pack is connected to the first end of the (3i-2)th contactor, the second end of the (3i-2)th contactor is connected to the second end of the load, and the positive terminal of the i-th battery pack is connected to the (i-1)th battery pack. A 3i-1 contactor is provided between the negative terminals, where 2≤i≤N; the plurality of switching switches also include a fifth switching switch to a 2N+2 switching switch, and the plurality of switching branches also include a fifth switching branch to a 2N+2 switching branch, wherein the 2i+1 switching branch includes a 2i+1 switching resistor, and the 2i+1 switching switch is used to control the 2i+1 switching branch to switch in or out between the positive terminal of the i-th battery pack and the reference ground; the 2i+2 switching branch includes a 2i+2 switching resistor, and the 2i+2 switching switch is used to control the 2i+2 switching branch to switch in or out between the negative terminal of the i-th battery pack and the reference ground.

[0075] In conjunction with the second aspect, in one possible implementation, the plurality of sampling branches include a first sampling branch and a second sampling branch, wherein a first end of the first sampling branch is connected to a second end of the (2i+1)th switching branch; and a first end of the second sampling branch is connected to a second end of the (2i+2)th switching branch.

[0076] Thirdly, a power management system is provided, the power management system including the detection device in the first aspect or any possible implementation of the first aspect.

[0077] Fourthly, a vehicle system is provided, the vehicle system including a detection device as described in the first aspect or any one of the first aspects. Attached Figure Description

[0078] Figure 1 This is a schematic diagram illustrating an application scenario of one embodiment of this application.

[0079] Figure 2 This is a schematic diagram of the structure of a detection device 200 according to an embodiment of this application.

[0080] Figure 3 This is a schematic diagram of the structure of a detection device 200 according to another embodiment of this application.

[0081] Figure 4 The battery pack voltage U of a battery system according to an embodiment of this application. batFlowchart of high voltage testing method

[0082] Figure 5 The load voltage U of a battery system according to an embodiment of this application load The flowchart of the high-voltage testing method.

[0083] Figure 6 This is a flowchart of an insulation detection method for a battery system according to an embodiment of this application.

[0084] Figure 7 This is a flowchart of a method for insulation testing of a battery system according to another embodiment of this application.

[0085] Figure 8 This is a flowchart of a contactor adhesion detection method according to an embodiment of this application.

[0086] Figure 9 This is a flowchart of a contactor adhesion detection method according to an embodiment of this application.

[0087] Figure 10 This is a schematic diagram of the detection device 200 in another embodiment of this application.

[0088] Figure 11 This is a schematic diagram of a detection device 200 according to an embodiment of this application. Detailed Implementation

[0089] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0090] For ease of understanding, several terms involved in the embodiments of this application will be described first.

[0091] A contactor is a device in electrical engineering that can quickly disconnect AC and DC main circuits and frequently connect and disconnect high-current control circuits. Contactors have a large control capacity, are suitable for frequent operation and remote control, and are one of the important components in automatic control systems. Contactors include AC contactors and DC contactors, and can be used in power, distribution, and consumption applications. In this embodiment, since the battery system outputs DC power, the contactor can be a DC contactor.

[0092] A battery management system (BMS) is a control system used to monitor and manage battery systems, typically applied to the management of power battery systems in electric vehicles. A BMS can perform various functions such as battery monitoring, calculation, and communication.

[0093] Figure 1 This is a schematic diagram illustrating an application scenario according to an embodiment of this application. For example... Figure 1As shown, this application scenario includes a battery system 100 and a detection device 200. The battery system 100 includes a battery pack 110, a first contactor 101, and a second contactor 102. The first contactor 101 and the second contactor 102 act as control switches for the external output of the battery system 100, controlling the on / off state of the external output circuit of the battery pack 110. The first terminal of the first contactor 101 is connected to the positive terminal of the battery pack 110. The second terminal of the first contactor 101 is connected to the positive output terminal of the battery system 100, or in other words, to the first terminal of a load (not shown in the figure). The first terminal of the second contactor 102 is connected to the negative terminal of the battery pack 110. The second terminal of the second contactor 102 is connected to the negative output terminal of the battery system 100, or in other words, to the second terminal of a load.

[0094] In some examples, the battery system 100 described above is a high-voltage battery system. Since it is used in a high-voltage battery system, the contactor described above is usually a contactor that can withstand high voltage and high current.

[0095] It should be understood that Figure 1 The components shown in the battery system 100 are merely examples. In practice, the battery system 100 may also include multiple battery packs 110 and multiple contactors, and may also include other components. Figure 1 Devices or functional modules not shown in the diagram.

[0096] It should be understood that Figure 1 The battery system 100 can be used in electric vehicles, smart cars, or hybrid vehicles, as well as in other fields.

[0097] like Figure 1 The detection device 200 is connected to the battery system 100 and is used to perform high voltage detection and insulation detection in the battery system 100.

[0098] Furthermore, the detection device 200 can also perform contactor adhesion detection on the battery system 100. Contactor adhesion detection refers to detecting whether the contacts in the contactor have become stuck together. When the mechanical contacts of the contactor are cut off under load, contact adhesion failure may occur, resulting in the inability to cut off the high-voltage output; therefore, it is necessary to detect the adhesion of the contactor contacts.

[0099] It should be understood that the detection device 200 can be a standalone module or integrated with other functional circuits. For example, the detection device 200 can be integrated into a BMS.

[0100] To facilitate understanding, the principles of high-voltage detection, insulation detection, and contactor contact adhesion detection will be introduced separately below.

[0101] High-voltage detection principle: It is used to calculate the battery pack voltage U based on the voltage information collected from the high-voltage battery system. bat Or the load voltage U load For example, the voltage across the battery pack 110 can refer to the voltage difference between the first terminal of the first contactor 101 and the first terminal of the second contactor 102. The load voltage can refer to the voltage difference between the second terminal of the first contactor 101 and the second terminal of the second contactor 102.

[0102] Insulation testing principle: Insulation testing is used to detect the insulation resistance R between the positive terminal and ground of battery pack 110. p and the insulation resistance R of the negative electrode to ground n Specifically, a switching resistor can be inserted or removed between the positive (and / or negative) terminal of battery pack 110 and the vehicle ground. The voltage between the positive (and / or negative) terminal of battery pack 110 and the vehicle ground can be calculated when the switching resistor is inserted and removed, respectively. Then, Kirchhoff's current theorem can be used to derive a system of equations to calculate the insulation resistance R between the positive terminal of battery pack 110 and ground. p and the insulation resistance R of the negative electrode to ground n .

[0103] The contactor adhesion detection principle is as follows: By comparing the voltage data at both ends of the contactor collected by the high-voltage detector, the current operating state of the contactor is determined. Then, it is determined whether the current operating state of the contactor is the same as the operating state indicated by the contactor control signal issued by the detection device 200. If they are the same, it means that the contactor contacts are not stuck; if they are different, it means that the contactor contacts are stuck.

[0104] Figure 2 This is a schematic diagram of the structure of a detection device 200 according to an embodiment of this application. Figure 2 As shown, the detection device 200 includes a cutting unit 201 and a processing unit 202.

[0105] The switching unit 201 includes multiple switching branches (221-224) and multiple switching switches (S1-S4). Each of the multiple switching branches includes a switching resistor (R1-R4). The multiple switching switches (S1-S4) are used to control the multiple switching branches to switch in or out between the following terminals and the reference ground: the positive terminal of the battery pack 110, the second terminal of the first contactor 101, the negative terminal of the battery pack 110, and the second terminal of the second contactor 102. The reference ground is used to connect to the vehicle body ground.

[0106] In some examples, the processing unit 202 can send a switching control signal to each of the plurality of switching switches (S1 to S4), and the processing unit 202 can control the on or off of each switching switch through the switching control signal.

[0107] In some examples, the processing unit 202 may also send contactor control signals to the first contactor 101 or the second contactor 102, the contactor control signals being used to control each contactor to be turned on or off.

[0108] This can be understood as follows: after the switching switches (S1~S4) corresponding to the switching branch are turned on, the switching resistors (R1~R4) in the switching branch will be switched between the corresponding terminals and the reference ground. After the switching switches (S1~S4) corresponding to the switching branch are turned off, the switching resistors (R1~R4) will be disconnected from the corresponding terminals.

[0109] Optionally, this application embodiment does not limit the resistance values ​​of the switching resistors (R1 to R4) in the above-mentioned multiple switching branches, and the resistance values ​​of the switching resistors (R1 to R4) can be determined according to practice. As an example, the resistance values ​​of the switching resistors (R1 to R4) can usually be relatively large, such as megaohm (MΩ) level resistors.

[0110] It should be understood that the above-mentioned switching branch may include one or more switching resistors. The following description uses the example of setting one switching resistor in each switching branch.

[0111] As an example, the aforementioned switching device may include at least one of the following switching devices: a relay, an optocoupler (photoMOS), or a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0112] The processing unit 202 is used to detect the sampling point voltage information of multiple switching branches, and the sampling point voltage information is used to indicate the sampling point voltage of multiple switching branches.

[0113] It should be understood that, depending on the detection purpose of the detection device 200, such as high-voltage detection, insulation detection, or contactor adhesion detection, the on / off states of the multiple switching switches (S1 to S4) corresponding to the sampling point voltage information will also be different. In other words, the sampling point voltage information includes the sampling point voltages of multiple switching branches under different on / off states of multiple switching switches (S1 to S4). The implementation methods of different detection methods will be further described later.

[0114] The processing unit 202 is used to acquire sampling point voltage information from the sampling unit, and determine high-voltage detection information and insulation detection information based on the sampling point voltage information. The high-voltage detection information includes at least one of the following: battery pack voltage U. bat and load voltage U load The insulation test information includes at least one of the following: the insulation resistance value R of the positive terminal of battery pack 110 to ground. pThe insulation resistance value R of the negative terminal of the battery pack 110 to ground n .

[0115] In this embodiment, the battery system detection device includes a switching unit. Multiple switching branches in the switching unit can flexibly switch between multiple terminals in the battery system and the reference ground. Using these multiple switching branches, the detection device 200 can detect the sampling point voltages of the multiple switching branches under different states, thereby achieving high-voltage detection and insulation detection of the battery system. Since the reference grounds of the multiple switching branches in the switching unit are all connected to the vehicle body ground, the detection device does not require electrical isolation for high-voltage detection and insulation detection. A single circuit can be used to achieve both high-voltage detection and insulation detection of the battery system, optimizing circuit design and improving the efficiency of battery system detection.

[0116] Furthermore, the processing unit 202 is also configured to determine at least one of the following information based on the sampling point voltage information: the contact status information of the first contactor 101 and the contact status information of the second contactor 102, wherein the contact status information is used to indicate whether the contacts of the contactors are stuck together.

[0117] See also Figure 2 As an example, the multiple switching branches include the first switching branch to the fourth switching branch (221 to 224), and the multiple switching switches include the first switching switch S1 to the fourth switching switch S4. The multiple switching branches and multiple switching switches correspond one-to-one.

[0118] The first switching branch 221 includes a first switching resistor R1, a first switching switch S1 connected in series with the first switching resistor R1, and the first end of the first switching branch 221 is connected to the positive terminal of the battery pack 110. The first switching switch S1 is used to control the first switching branch 221 to switch into or out of the positive terminal of the battery pack 110 and the reference ground.

[0119] The second switching branch 222 includes a second switching resistor R2, and a second switching switch S2 is connected in series with the second switching resistor R2. The first end of the second switching branch 222 is connected to the negative terminal of the battery pack 110. The second switching switch S2 is used to control the second switching branch 222 to switch into or out of the negative terminal of the battery pack 110 and the reference ground.

[0120] The third switching branch 223 includes a third switching resistor R3, a third switching switch S3 connected in series with the third switching resistor R3, a first end of the third switching branch 223 connected to the second end of the first contactor 101, and the third switching switch S3 is used to control the third switching branch 223 to switch into or out of the second end of the first contactor 101 and the reference ground.

[0121] The fourth switching branch 224 includes a fourth switching resistor R4, a fourth switching switch S4 connected in series with the fourth switching resistor R4, a first terminal of the fourth switching branch 224 connected to the second terminal of the second contactor 102, and the fourth switching switch S4 is used to control the fourth switching branch 224 to switch into or out of the second terminal of the second contactor 102 and the reference ground.

[0122] See also Figure 2 The switching unit 201 also includes multiple sampling branches (2011, 2012), which are used to provide the sampling point voltage corresponding to the switching branch. Optionally, the sampling branches can be arranged between the multiple switching branches and the reference ground. For example, the first end of each of the multiple sampling branches is connected to the second end of at least one of the multiple switching branches, and the second end of each sampling branch is connected to the reference ground.

[0123] As an example, Figure 2 The following example illustrates a multi-sampling branch system, including two sampling branches (2011, 2012). The first end of the first sampling branch 2011 is connected to the second end of the first switching branch 221 and the second end of the third switching branch 223. The first end of the second sampling branch 2012 is connected to the second end of the second switching branch 222 and the second end of the fourth switching branch 224.

[0124] It should be understood that the connection between devices or circuits in the embodiments of this application may include direct connection and indirect connection. In the case of indirect connection, other devices may also be provided between devices or circuits.

[0125] See also Figure 2 In some examples, each of the multiple sampling branches includes an upsampling resistor (Rsampling). 11 R 21 ) and downsampling resistor (R 12 R 22 ), upsampling resistor (R) 11 R 21 The first terminal of the sampling resistor (R) is connected to the first terminal of each sampling branch. 11 R 21 The second terminal of ) is connected to the downsampling resistor (R) 12 R 22 Connect the first terminal of ) to the downsampling resistor (R) 12 R 22 The second terminal of the circuit is connected to the reference ground, where the sampling point voltage of the switching branch is the voltage across the sampling resistor (R). 12 R 22 The voltage at the second terminal of ).

[0126] It should be understood that, Figure 2In this circuit, both the first switching branch 221 and the third switching branch 223 correspond to the first sampling branch 2011. When the first switching switch S1 is on and the third switching switch S3 is off, the first switching branch 221 is connected to the circuit, and the sampling point voltage detected by the first sampling branch 2011 is the sampling point voltage corresponding to the first switching branch 221. When the first switching switch S1 is off and the third switching switch S3 is on, the third switching branch 223 is connected to the circuit, and the sampling point voltage detected by the second sampling branch is the sampling point voltage corresponding to the third switching branch 223. Similarly, both the second switching branch 222 and the fourth switching branch 224 correspond to the second sampling branch 2012.

[0127] In some examples, after acquiring the sampling point voltage of the switching branch, the processing unit 202 can calculate the voltage at the terminal corresponding to the switching branch based on the voltage divider principle. For example, it can calculate the voltage at the positive or negative terminal of the battery pack.

[0128] It should be understood that Figure 2 The sampling branch shown is merely an example and not a limitation. Other implementations of the sampling branch are also possible, as long as they effectively provide the sampling point voltage for the switching branch. For example, Figure 2 The switching unit 201 can include four sampling branches, and the four sampling branches correspond one-to-one with the four switching branches.

[0129] It should be understood that Figure 2 This is merely an example of one specific implementation of the detection device 200. The switching unit 201 can also be implemented in other ways, as long as it can realize the switching in and out between multiple switching branches and multiple terminals in the battery system, and the reference ground of the multiple switching branches is the vehicle body ground. For example, the following Figure 3 Another implementation of the detection device 200 is shown.

[0130] Figure 3 This is a schematic diagram of the structure of a detection device 200 according to another embodiment of this application. Figure 3 As shown, the switching branch includes a first switching branch 221 and a second switching branch 222, the multiple switching resistors include a first switching resistor R1 and a second switching resistor R2, and the multiple switching switches include a first switching switch S1 and a second switching switch S2, wherein the first switching switch S1 and the second switching switch S2 are single-pole multi-throw switches.

[0131] The first switching branch 221 includes a first switching resistor R1. The first terminal of the first switching switch S1 is connected to the first terminal of the first switching branch 221. The second terminal of the first switching switch S1 is connected to the following terminals: the positive terminal of the battery pack 110, the second terminal of the first contactor 101, and the floating terminal (NC).

[0132] The second switching branch 222 includes a second switching resistor R2. The second terminal of the second switching switch S2 is connected to the first terminal of the second switching branch 222. The second terminal of the second switching switch S2 is connected to the following terminals: the negative terminal of the battery pack 110, the second terminal of the second contactor 102, and the floating terminal (NC).

[0133] Among them, the floating terminal can refer to the second terminal of the switching switch not being connected to any potential and being in the open state.

[0134] Next, we will combine Figure 2 The detection device 200 shown in this application details the high voltage detection method, insulation detection method, and contactor contact adhesion detection method in the embodiments of this application.

[0135] Figure 4 The battery pack voltage U is an embodiment of this application. bat A flowchart of the high-voltage testing method. (For example...) Figure 4 As shown, the method includes:

[0136] S401, the processing unit 202 controls multiple switching switches to be in a first working state, the first working state being: the first switching switch S1 and the second switching switch S2 are turned on, and the third switching switch S3 and the fourth switching switch S4 are turned off.

[0137] As an example, the processing unit 202 can send switching control signals to multiple switching switches respectively, and the switching control signals are used to control the on / off state of each switch. In this case, the positive terminal of the battery pack is connected to the reference ground through the first switching branch 221, and the negative terminal of the battery pack is connected to the reference ground through the second switching branch 222.

[0138] S402, when multiple switching switches are in the first working state, the processing unit 202 detects the first sampling point voltage U1 of the first switching branch 221 and the second sampling point voltage U2 of the second switching branch 222.

[0139] Specifically, the voltage U1 at the first sampling point is the upsampling resistor R in the first sampling branch 2011. 11 The voltage at the second terminal, and the voltage U2 at the second sampling point, is the upsampling resistor R in the second sampling branch 2012. 21 The voltage at the second terminal.

[0140] S403, Processing unit 202 determines the battery pack voltage U based on the first sampling point voltage U1 and the second sampling point voltage U2. bat .

[0141] Specifically, the processing unit 202 can calculate the positive voltage U of the battery pack according to the voltage divider theorem. p and negative voltage U nAnd further calculate the battery pack voltage U bat The formula is as follows:

[0142] U bat =U p -U n (1)

[0143] U p =U1×(R1+R 11 +R 12 ) / R 12 (2)

[0144] U n =U2×(R2+R 21 +R 22 ) / R 22 (3)

[0145] Among them, U p U represents the positive voltage of the battery pack. n R1 represents the negative terminal voltage of the battery pack, R2 represents the resistance of the first switching resistor R1, and R2 represents the resistance of the second switching resistor R2. 11 R represents the upsampling resistor of the first sampling branch 2011. 11 The resistance value, R 12 R represents the downsampling resistor of the first sampling branch 2011. 12 The resistance value, R 21 R represents the upsampling resistor of the second sampling branch 2012. 21 The resistance value, R 22 R represents the downsampling resistor of the second sampling branch 2012. 22 The resistance value.

[0146] Figure 5 The load voltage U of a battery system according to an embodiment of this application load A flowchart of the high-voltage testing method. (For example...) Figure 5 As shown, the method includes:

[0147] S501, the processing unit 202 controls multiple switching switches, the first contactor 101 and the second contactor 102 to be in a second working state. The second working state is: the first switching switch S1 and the second switching switch S2 are open, the third switching switch S3 and the fourth switching switch S4 are on, and the first contactor 101 and the second contactor 102 are open.

[0148] In this case, the second end of the first contactor 101 is connected to the reference ground through the first switching branch 221, and the second end of the second contactor 102 is connected to the reference ground through the second switching branch 222.

[0149] As an example, the processing unit 202 can send switching control signals to multiple switching switches respectively, and the switching control signals are used to control the on and off of each switch.

[0150] As an example, the processing unit 202 can send contactor control signals to the first contactor 101 and the second contactor 102 to control the first contactor 101 and the second contactor 102 to be in an open state so as to detect the load voltage.

[0151] S502, when multiple switching switches are in the second working state, the processing unit 202 detects the third sampling point voltage U3 of the third switching branch 223 and the fourth sampling point voltage U4 of the fourth switching branch 224.

[0152] Specifically, the voltage U3 at the third sampling point is the upsampling resistor R in the first sampling branch 2011. 11 The voltage at the second terminal, and the voltage U4 at the fourth sampling point, are the upsampling resistor R in the second sampling branch 2012. 21 The voltage at the second terminal.

[0153] S503, the processing unit 202 determines the load voltage U based on the voltage U3 at the third sampling point and the voltage U4 at the fourth sampling point. load .

[0154] As an example, the processing unit 202 can calculate the first terminal voltage U of the load according to the voltage divider theorem. p 'and the second terminal voltage U of the load n ', and further calculate the load voltage U load The formula is as follows:

[0155] U load =U p '-U n '; (4)

[0156] U p =U3×(R3+R 11 +R 12 ) / R 12 (5)

[0157] U n =U4×(R4+R 21 +R 22 )R 12 (6)

[0158] Among them, U p ' represents the voltage at the first terminal of the load, U n ' represents the second terminal voltage of the load, R3 represents the resistance value of the third switching resistor R3, R4 represents the resistance value of the fourth switching resistor R4, R 11R represents the upsampling resistor of the first sampling branch 2011. 11 The resistance value, R 12 R represents the downsampling resistor of the first sampling branch 2011. 12 The resistance value, R 21 R represents the upsampling resistor of the second sampling branch 2012. 21 The resistance value, R 22 R represents the downsampling resistor of the second sampling branch 2012. 22 The resistance value.

[0159] Figure 6 This is a flowchart of an insulation detection method for a battery system according to an embodiment of this application. Figure 6 As shown, the method includes:

[0160] S601, the processing unit 202 controls multiple switching switches to be in a first working state, the first working state being: the first switching switch S1 and the second switching switch S2 are turned on, and the third switching switch S3 and the fourth switching switch S4 are turned off.

[0161] S602, when multiple switching switches are in the first working state, the processing unit 202 detects the first sampling point voltage U1 of the first switching branch 221 and the second sampling point voltage U2 of the second switching branch 222.

[0162] S603, the processing unit 202 controls multiple switching switches to be in a third working state, in which the first switching switch S1 is turned on and the second switching switch S2 to the fourth switching switch S4 are turned off.

[0163] S604, when multiple switching switches are in the third working state, the processing unit 202 detects the voltage U5 at the fifth sampling point of the first switching branch 221.

[0164] S605, the processing unit 202 determines the positive terminal-to-ground insulation resistance value R of the battery pack based on the first sampling point voltage U1, the second sampling point voltage U2, and the fifth sampling point voltage U5. p The insulation resistance value R of the negative terminal of the battery pack to ground n .

[0165] Specifically, the processing unit 202 can calculate the insulation resistance value R of the positive terminal to ground of the battery pack according to the voltage divider theorem and Kirchhoff's current theorem. p The insulation resistance value R of the negative terminal of the battery pack to ground n The formula is as follows:

[0166] U p1 / (R p / / (R1+R 11 +R 12 ))=-Un1 / (R n / / (R2+R 21 +R 22 (7)

[0167] U p2 / (R p / / (R1+R 11 +R 12 ))=-U n2 / R n (8)

[0168] U p1 =U1×(R1+R 11 +R 12 ) / R 12 (9)

[0169] U n1 =U2×(R2+R 21 +R 22 ) / R 22 (10)

[0170] U p2 =U5×(R1+R 11 +R 12 ) / R 12 (11)

[0171] U n2 =U n1 -U p1 +U p2 (12)

[0172] Among them, U p1 U represents the positive voltage of the battery pack in its first operating state. n1 U represents the negative terminal voltage of the battery pack in its first operating state. p2 U represents the positive voltage of the battery pack in its third operating state. n2 This indicates the negative terminal voltage of the battery pack in the third operating state. R1 represents the resistance value of the first switching resistor R1, and R2 represents the resistance value of the second switching resistor R2. 11 R represents the upsampling resistor of the first sampling branch 2011. 11 The resistance value, R 12 R represents the downsampling resistor of the first sampling branch 2011. 12 The resistance value, R 21 R represents the upsampling resistor of the second sampling branch 2012. 21 The resistance value, R 22 R represents the downsampling resistor of the second sampling branch 2012. 22 The resistance value.

[0173] Formulas (7) and (8) utilize Kirchhoff's current principle, which states that the current flowing from the positive terminal of the battery pack to the ground is equal to the current flowing from the ground to the negative terminal of the battery pack. Formulas (9) to (11) utilize the principle of voltage division by resistors. Formula (12) utilizes the principle that the battery pack voltage remains constant.

[0174] Optionally, in S603 to S605, the processing unit 202 can also control multiple switching switches to be in a fourth operating state. The fourth operating state includes: the second switching switch S2 being turned on, and the first switching switch S1, the third switching switch S3, and the fourth switching switch S4 being turned off. The processing unit 202 can detect the sixth sampling point voltage U6 of the second switching branch 222 when multiple switching switches are in the fourth operating state. Furthermore, it determines the positive terminal-to-ground insulation resistance value R of the battery pack based on the first sampling point voltage U1, the second sampling point voltage U2, and the sixth sampling point voltage U6. p The insulation resistance value R of the negative terminal of the battery pack to ground n .

[0175] Accordingly, the processing unit 202 can calculate R according to the following formula. p and R n .

[0176] U p1 / (R p / / (R1+R 11 +R 12 ))=-U n1 / (R n / / (R2+R 21 +R 22 (13)

[0177] U p3 / R p =-U n3 / (R n / / R2+R 21 +R 22 (14)

[0178] U p1 =U1×(R1+R 11 +R 12 ) / R 12 (15)

[0179] U n1 =U2×(R2+R 21 +R 22 ) / R 22 (16)

[0180] U n3 =U6×(R2+R 21 +R22 ) / R 22 (17)

[0181] U p3 =U p1 -U n1 +U n3 (18)

[0182] Among them, U p1 U represents the positive voltage of the battery pack in its first operating state. n1 U represents the negative terminal voltage of the battery pack in its first operating state. p3 U represents the positive voltage of the battery pack in its fourth operating state. n3 This indicates the negative terminal voltage of the battery pack in the fourth operating state. R1 represents the resistance value of the first switching resistor R1, and R2 represents the resistance value of the second switching resistor R2. 11 R represents the upsampling resistor of the first sampling branch 2011. 11 The resistance value, R 12 R represents the downsampling resistor of the first sampling branch 2011. 12 The resistance value, R 21 R represents the upsampling resistor of the second sampling branch 2012. 21 The resistance value, R 22 R represents the downsampling resistor of the second sampling branch 2012. 22 The resistance value.

[0183] It should be understood that Figure 6 The proposed solution is merely an illustrative example of insulation testing. In conjunction with the testing device 200 provided in this application, the control unit can control multiple switching switches to other operating states and acquire the corresponding sampling point voltages to calculate the positive-to-ground insulation resistance value R of the battery pack. p The insulation resistance value R of the negative terminal of the battery pack to ground n .

[0184] Next, combine Figure 7 The following describes specific examples of the insulation testing method of this application.

[0185] Figure 7 This is a flowchart of an insulation detection method for a battery system according to another embodiment of this application. Figure 7 As shown, the method includes:

[0186] S701, the processing unit 202 controls multiple switching switches to be in the first working state, that is, the first switching switch S1 and the second switching switch S2 are turned on, and the third switching switch S3 and the fourth switching switch S4 are turned off.

[0187] S702. When multiple switching switches are in the first working state, the processing unit 202 acquires the first sampling point voltage U1 of the first switching branch 221 and the second sampling point voltage U2 of the second switching branch 222.

[0188] S703 and processing unit 202 calculate the positive voltage U of the battery pack based on U1 and U2 and the voltage divider principle. p1 and the negative terminal voltage U of the battery pack n1 .

[0189] Among them, the positive voltage U of the battery pack p1 and the negative terminal voltage U of the battery pack n1 The calculation method can be found in [reference]. Figure 6 The relevant descriptions in the document will not be repeated here.

[0190] S704, Processing unit 202 determines U p1 and U n1 The size of U p1 >U n1 If U is disconnected, the second switching switch S2 will be disconnected, the states of the remaining switching switches will remain unchanged, and S705 will be executed; if U p1 <U n1 If the first switching switch S1 is disconnected, the states of the other switching switches remain unchanged, and S706 is executed.

[0191] In S704, in U p1 The voltage is greater than U n1 In this case, it indicates the insulation resistance R of the battery pack positive terminal to ground. p Greater than the insulation resistance value R of the negative terminal of the battery pack to ground n If the second switching switch S2 is disconnected, R will be calculated using formulas (7) to (12). p and R n In formula (8), R p and (R1+R 11 +R 12 The resistance value after parallel connection is relative to R n The resistance values ​​are closer in magnitude, thus reducing errors in subsequent calculations. In this case, if the first switching switch S1 is turned off, R needs to be calculated using formulas (13) to (18). p and R n In formula (14), R n With (R2+R) 21 +R 22 The resistance value after parallel connection is relative to R p The magnitudes of the resistance values ​​differ even more, which will lead to an increase in calculation errors.

[0192] Similarly, in U p1 The voltage is less than Un1 In this case, the first switching switch S1 is disconnected, and R is calculated using formulas (13) to (18). p and R n The calculation error will be smaller.

[0193] Therefore, R is calculated using the method in S704. p and R n It can improve the computational R p and R n The accuracy.

[0194] S705. If the second switching switch S2 is disconnected in S704, the processing unit 202 obtains the voltage U5 at the fifth sampling point of the first switching branch 221, and calculates the positive terminal-to-ground insulation resistance value R of the battery pack based on U1, U2 and U5. p And the insulation resistance value R of the negative terminal of the battery pack to ground. n .

[0195] Specifically, R can be calculated according to formulas (7) to (12). p and R n This will not be elaborated upon here.

[0196] S706. If the first switching switch S1 is disconnected in S704, the processing unit 202 obtains the voltage U6 at the sixth sampling point of the second switching branch 222, and calculates the positive terminal-to-ground insulation resistance value R of the battery pack based on U1, U2 and U6. p And the insulation resistance value R of the negative terminal of the battery pack to ground. n .

[0197] Specifically, R can be calculated according to formulas (13) to (18). p and R n This will not be elaborated upon here.

[0198] Next, combine Figure 8 and Figure 9 This application introduces a contactor adhesion detection method according to an embodiment of the present application.

[0199] Figure 8 This is a flowchart of a contactor adhesion detection method according to an embodiment of this application. Figure 8 The following explanation uses the detection of the first contactor 101 as an example. Figure 8 As shown, the method includes:

[0200] S801, the processing unit 202 controls the first switching switch S1 to be turned on, and obtains the voltage U at the first terminal of the first contactor 101. c1 .

[0201] S802, the processing unit 202 controls the third switching switch S3 to be turned on, and obtains the voltage U at the second terminal of the first contactor 101. c2 .

[0202] Specifically, the processing unit 202 can acquire the sampling point voltages of the first switching branch 221 and the second switching branch 222 respectively, and calculate U using the voltage divider principle. c1 and U c2 .

[0203] S803, Processing unit 202 according to U c1 and U c2 The actual working state of the first contactor 101 is determined.

[0204] For example, the processing unit 202 can be based on U c1 -U c2 Whether it exceeds a preset threshold U0 is used to determine the actual operating state of the first contactor 101. If U c1 -U c2 If U ≥ U0, then the actual working state of the first contactor 101 is determined to be the open state; if U c1 -U c2 If the value is less than U0, then the first contactor 101 is determined to be in the closed state. The value of the preset threshold U0 can be determined in practice.

[0205] S804, the processing unit 202 obtains the indicated working state of the first contactor 101, which is the working state of the first contactor 101 indicated by the contactor control signal.

[0206] S805, the processing unit 202 determines the contact status information of the first contactor 101 based on whether the actual working state and the indicated working state are consistent.

[0207] For example, if the processing unit 202 determines whether the actual working state of the first contactor 101 is consistent with the indicated working state, and if they are consistent, then the contact status information is determined to be that the first contactor 101 has not experienced contact adhesion; if they are inconsistent, then the contact status information is determined to be that the first contactor 101 has experienced contact adhesion.

[0208] Figure 9 This is a flowchart of a contactor adhesion detection method according to an embodiment of this application. Figure 9 The following explanation uses the detection of the first contactor 101 as an example. Figure 9 As shown, the method includes:

[0209] S901, the processing unit 202 controls the first switching switch S1 to be turned on, and obtains the voltage U at the first terminal of the first contactor 101. c1 .

[0210] S902, the processing unit 202 controls the third switching switch S3 to be turned on, and obtains the voltage U at the second terminal of the first contactor 101. c2 .

[0211] S903, Processing unit 202 according to U c1 -U c2 Whether it is greater than the preset threshold U0 is used to determine the actual working state of the first contactor 101.

[0212] S904, if U c1 -U c2 If U ≥ U0, then the actual working state of the first contactor 101 is determined to be the open state; if U c1 -U c2 If <U0, then the first contactor 101 is determined to be in the closed state.

[0213] S905, the processing unit 202 determines whether the actual working state of the first contactor 101 is consistent with the working state indicated by the contactor control signal. If they are consistent, it is determined that the first contactor 101 has not experienced contact sticking and the contacts are normal; if they are inconsistent, it is determined that the first contactor 101 has experienced contact sticking.

[0214] Figure 10 This is a schematic diagram of the detection device 200 in another embodiment of this application. For example... Figure 10 As shown, as an example, processing unit 202 may also include multiple sub-units to implement the various steps executed by processing unit 202 as described above. For example... Figure 10 As shown, the processing unit 202 may include a calculation unit 2021, a control unit 2022, a driving unit 2023, and a sampling unit 2024. The functions of each of the above units are described below.

[0215] Sampling unit 2024: Used to collect the sampling point voltage information of the switching branch in the switching unit 201, and transmit the acquired sampling point voltage information to the calculation unit.

[0216] Calculation unit 2021: Used to perform calculations and logical processing based on the sampling point voltage information collected by sampling unit 2024. The calculation unit is also used to obtain information on the indicator contactor control signal or switching control signal from control unit 2022, and perform calculations and logical processing thereon.

[0217] Control unit 2022: Used to send contactor control signals or switching control signals to drive unit 2023. The contactor control signal is used to control the on / off state of the contactor, and the switching control signal is used to control the on / off state of the switch inside the switching unit.

[0218] Drive unit 2023: Used to receive contactor control signals or switching control signals sent by computing unit 2021, and drive the contactor or the switching switch in the switching unit according to the contactor control signals or switching control signals.

[0219] It should be understood that Figure 10 The various sub-units can be integrated into a single module or set up in different modules.

[0220] The above description uses a battery system comprising a single battery pack as an example to illustrate the detection device 200. Optionally, the detection device 200 in this embodiment can also be applied to a battery system with multiple battery packs. The following will discuss this further. Figure 11 The following describes a detection device 200 applicable to battery systems with multiple battery packs.

[0221] Figure 11 This is a schematic diagram of a detection device 200 according to an embodiment of this application. Figure 11 As shown, the battery system includes N battery packs and contactors from the first contactor to the 3N-1th contactor. Figure 2 The battery pack in the diagram can be the first battery pack among N battery packs. The positive terminal of the i-th battery pack is connected to the first terminal of the (3i-3)-th contactor, and the second terminal of the (3i-3)-th contactor is connected to the first terminal of the load. The negative terminal of the i-th battery pack is connected to the first terminal of the (3i-2)-th contactor, and the second terminal of the (3i-2)-th contactor is connected to the second terminal of the load. Furthermore, a (3i-1)-th contactor is installed between the positive terminal of the i-th battery pack and the negative terminal of the (i-1)-th battery pack. N ≥ 2, 2 ≤ i ≤ N.

[0222] Optionally, by controlling the on / off state of the 3N-1 contactors, the N battery packs can be flexibly connected in series, in parallel, or in a series-parallel combination.

[0223] See also Figure 11 The multiple switching switches mentioned above also include the fifth switching switch to the 2N+2nd switching switch, and the multiple switching branches also include the fifth switching branch to the 2N+2nd switching branch.

[0224] Among them, the 2i+1th switching branch includes the 2i+1th switching resistor R 2i+1 , the 2i+1th switching switch S 2i+1 Used to control the connection or disconnection of the 2i+1 switching branch between the positive terminal of the i-th battery pack and the reference ground;

[0225] The 2i+2nd switching branch includes the 2i+2nd switching resistor R. 2i+2 The 2i+2 switching switch is used to control the switching of the 2i+2 switching branch between the negative terminal of the i-th battery pack and the reference ground.

[0226] Optionally, the first end of the first sampling branch 2011 is connected to the second end of the 2i+1th switching branch; the first end of the second sampling branch 2012 is connected to the second end of the 2i+2th switching branch.

[0227] It should be understood that Figure 11 The battery system in the text can flexibly realize various combinations of multiple battery packs, such as series, parallel, or series-parallel connections. Combined with the description above, Figure 11 The detection device 200 can perform high voltage detection, insulation detection, and contact contact adhesion detection on a single battery pack or various combinations thereof.

[0228] Optionally, Figure 11 The detection device 200 can also be modified appropriately. For example, the connection relationship or number of multiple switching branches and multiple sampling branches can be changed, as long as it can realize the function of detecting the voltage of different terminals in the battery system.

[0229] In the embodiments of this application, the switching branch in the switching unit of the battery system detection device can be expanded based on the number and connection method of the battery packs in the battery system to be tested, thereby using a single circuit to realize high voltage detection and insulation detection of a battery system including multiple battery packs, which can optimize circuit design and improve the efficiency of circuit detection.

[0230] As used in this specification, the terms "component," "module," "system," etc., are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0231] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0232] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0233] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0234] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0235] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0236] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0237] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A detection device for a battery system, characterized by, The battery system comprises a battery pack, a first contactor and a second contactor, a first end of the first contactor is connected with a positive electrode of the battery pack, a first end of the second contactor is connected with a negative electrode of the battery pack, a second end of the first contactor is used for being connected with a first end of a load, a second end of the second contactor is used for being connected with a second end of the load, and the detection device comprises: A switching unit comprises a plurality of switching branches and a plurality of switching switches, each of the plurality of switching branches comprises a switching resistance, and the plurality of switching switches are used for controlling the plurality of switching branches to be switched in or out of a plurality of terminals and a reference ground between the positive electrode of the battery pack, the second end of the first contactor, the negative electrode of the battery pack, the second end of the second contactor, wherein the reference ground is used for connecting a vehicle body ground. The processing unit is configured to: detect sampling point voltage information of the plurality of switching branches, the sampling point voltage information being used to indicate sampling point voltages of the plurality of switching branches; and determine high-voltage detection information and insulation detection information according to the sampling point voltage information, wherein the high-voltage detection information includes at least one of: a battery pack voltage U bat and a load voltage U load , and the insulation detection information includes at least one of: a positive electrode-to-ground insulation resistance value R p of the battery pack and a negative electrode-to-ground insulation resistance value R n of the battery pack. The plurality of switching branches comprise a first switching branch to a fourth switching branch, and the plurality of switching switches comprise a first switching switch to a fourth switching switch, wherein: The first switching branch comprises a first switching resistance, and the first switching switch is used for controlling the first switching branch to be switched in or out of the positive electrode of the battery pack and the reference ground; The second switching branch comprises a second switching resistance, and the second switching switch is used for controlling the second switching branch to be switched in or out of the negative electrode of the battery pack and the reference ground; The third switching branch comprises a third switching resistance, and the third switching switch is used for controlling the third switching branch to be switched in or out of the second end of the first contactor and the reference ground; The fourth switching branch comprises a fourth switching resistance, and the fourth switching switch is used for controlling the fourth switching branch to be switched in or out of the second end of the second contactor and the reference ground; The switching unit further comprises a plurality of sampling branches, and the plurality of sampling branches comprise a first sampling branch and a second sampling branch, wherein: A first end of the first sampling branch is connected with a second end of the first switching branch and a second end of the third switching branch; A second end of the second sampling branch is connected with a second end of the second switching branch and a second end of the fourth switching branch.

2. The detection device of claim 1, wherein, The processing unit is further used for determining at least one of the following information according to the sampling point voltage information: Contact point state information of the first contactor and contact point state information of the second contactor, wherein the contact point state information is used for indicating whether contact point adhesion of a contactor occurs.

3. The detection device of claim 1, wherein, Each of the plurality of sampling branches comprises an upper sampling resistance and a lower sampling resistance, a first end of each of the upper sampling resistances is connected with a first end of each sampling branch, a second end of each of the upper sampling resistances is connected with a first end of the corresponding lower sampling resistance, and a second end of each of the lower sampling resistances is connected with the reference ground, wherein the sampling point voltage of the switching branch is a voltage of the second end of the upper sampling resistance.

4. The detection device of claim 1, wherein, The processing unit is specifically used for: The control unit is configured to: control the plurality of switching switches to be in a first working state, the first working state being that the first switching switch and the second switching switch are turned on, and the third switching switch and the fourth switching switch are turned off; determining the battery pack voltage U based on the first sampling point voltage U1 and the second sampling point voltage U2 bat .

5. The detection device of claim 4, wherein, The processing unit is specifically configured to determine the battery pack voltage U according to the following formula bat : U bat = U p - U n ; U p = U1 x (R1+R 11 +R 12 ) / R 12 ; U n = U2 x (R2 + R 21 + R 22 )R 22 ; wherein U p represents a positive electrode voltage of the battery pack, U n represents a negative electrode voltage of the battery pack, R1 represents a resistance value of the first switching resistance, R2 represents a resistance value of the second switching resistance, R 11 represents a resistance value of the up-sampling resistance of the first sampling branch, R 12 represents a resistance value of the down-sampling resistance of the first sampling branch, R 21 represents a resistance value of the up-sampling resistance of the second sampling branch, R 22 represents a resistance value of the down-sampling resistance of the second sampling branch.

6. The assay device of any one of claims 1, 4 or 5, wherein, detect a first sampling point voltage U1 of the first switching branch and a second sampling point voltage U2 of the second switching branch when the plurality of switching switches are in the first working state; and The processing unit is specifically configured to: control the plurality of switching switches, the first contactor, and the second contactor to be in a second working state, the second working state being that the first switching switch and the second switching switch are turned off, the third switching switch and the fourth switching switch are turned on, and the first contactor and the second contactor are turned off; detect a third sampling point voltage U3 of the third switching branch and a fourth sampling point voltage U4 of the fourth switching branch when the plurality of switching switches, the first contactor, and the second contactor are in the second working state; and determining the load voltage U based on the third sampling point voltage U3 and the fourth sampling point voltage U4 load .

7. The detection device of claim 6, wherein, The processing unit is specifically configured to determine the load voltage U according to the following formula load : U load = U p ' - U n '; U p ’ = U3 x (R3 + R 11 +R 12 ) / R 12 ; U n ’ = U4 x (R4 + R 21 +R 22 )R 12 ; wherein U p represents a first end voltage of the load, U n represents a second end voltage of the load, R3 represents a resistance value of the third switching resistance, R4 represents a resistance value of the fourth switching resistance, R 11 represents a resistance value of the up-sampling resistance of the first sampling branch, R 12 represents a resistance value of the down-sampling resistance of the first sampling branch, R 21 represents a resistance value of the up-sampling resistance of the second sampling branch, R 22 represents a resistance value of the down-sampling resistance of the second sampling branch.

8. The assay device of any one of claims 1, 4 or 5, wherein, The processing unit is specifically configured to: control the plurality of switching switches to be in a first working state, the first working state being that the first switching switch and the second switching switch are turned on, and the third switching switch and the fourth switching switch are turned off; detect a first sampling point voltage U1 of the first switching branch and a second sampling point voltage U2 of the second switching branch when the plurality of switching switches are in the first working state; and control the plurality of switching switches to be in a third working state, the third working state being that the first switching switch is turned on, and the second switching switch to the fourth switching switch are turned off; detect a fifth sampling point voltage U5 of the first switching branch when the plurality of switching switches are in the third working state; determine a positive electrode-to-ground insulation resistance value R of the battery pack according to the first sampling point voltage U1, the second sampling point voltage U2 and the fifth sampling point voltage U5 p a negative electrode-to-ground insulation resistance value R of the battery pack n .

9. The detection device of claim 8, wherein, The processing unit is specifically configured to determine the positive electrode-to-ground insulation resistance value R of the battery pack according to the following formula p , the negative electrode-to-ground insulation resistance value R of the battery pack n : U p1 / (R p / / (R1+R 11 +R 12 ))=-U n1 / (R n / / (R2+R 21 +R 22 )); U p2 / (R p / / (R1+R 11 +R 12 ))=-U n2 / R n ; U p1 = U1 x (R1+R 11 +R 12 ) / R 12 ; U n1 = U2 x (R2 + R 21 + R 22 ) / R 22 ; U p2 = U5 x (R1+R 11 +R 12 ) / R 12 ; U n2 = U n1 - U p1 + U p2 ; wherein, U p1 represents the positive electrode voltage of the battery pack in the first working state, U n1 represents the negative electrode voltage of the battery pack in the first working state, U p2 represents the positive electrode voltage of the battery pack in the third working state, U n2 represents the negative electrode voltage of the battery pack in the third working state, R1 represents the resistance value of the first switching resistance, R2 represents the resistance value of the second switching resistance, R 11 represents the resistance value of the up-sampling resistance of the first sampling branch, R 12 represents the resistance value of the down-sampling resistance of the first sampling branch, R 21 represents the resistance value of the up-sampling resistance of the second sampling branch, R 22 represents the resistance value of the down-sampling resistance of the second sampling branch.

10. The assay device of any one of claims 1, 4 or 5, wherein, The processing unit is further configured to: controlling the first switching switch to be conductive, and acquiring a voltage U of the first end of the first contactor c1 ; controlling the third switching switch to be conductive, and acquiring the voltage U of the second end of the first contactor c2 ; According to U c1 and U c2 , determine the actual operating state of the first contactor; obtain an indicated working state of the first contactor, the indicated working state being a working state of the first contactor indicated by a contactor control signal; obtain contact state information of the first contactor according to whether the actual working state and the indicated working state are consistent.

11. The assay device of any one of claims 1, 4 or 5, wherein, The battery system includes N battery packs, the battery pack being a first battery pack in the N battery packs, and the battery system further includes third to 3N-1 contactors, N≥2; wherein a positive electrode of an i-th battery pack in the N battery packs is connected to a first end of a 3i-3 contactor, a second end of the 3i-3 contactor is configured to be connected to a first end of the load, a negative electrode of the i-th battery pack is connected to a first end of a 3i-2 contactor, a second end of the 3i-2 contactor is connected to a second end of the load, and a 3i-1 contactor is arranged between the positive electrode of the i-th battery pack and the negative electrode of an i-1-th battery pack, 2≤i≤N; The plurality of switching switches further include fifth to 2N+2 switching switches, and the plurality of switching branches further include fifth to 2N+2 switching branches. The 2i+1 switching branch includes a 2i+1 switching resistor, and a 2i+1 switching switch is used to control the 2i+1 switching branch to cut in or cut out between the positive electrode of the i th battery pack and the reference ground; The 2i+2 switching branch includes a 2i+2 switching resistor, and a 2i+2 switching switch is used to control the 2i+2 switching branch to cut in or cut out between the negative electrode of the i th battery pack and the reference ground.

12. The detection device of claim 11, wherein, The plurality of sampling branches includes a first sampling branch and a second sampling branch, The first end of the first sampling branch is connected to the second end of the 2i+1 switching branch; The first end of the second sampling branch is connected to the second end of the 2i+2 switching branch.

13. A detection method for a battery system, characterized by, The battery system includes a battery pack, a first contactor and a second contactor, the first end of the first contactor is connected to the positive electrode of the battery pack, the first end of the second contactor is connected to the negative electrode of the battery pack, the second end of the first contactor is used to be connected to the first end of the load, and the second end of the second contactor is used to be connected to the second end of the load, The method is executed by a detection device, the detection device includes a switching unit and a processing unit, the processing unit includes a plurality of switching branches and a plurality of switching switches, each of the plurality of switching branches includes a switching resistor, and the plurality of switching switches are used to control the plurality of switching branches to cut in or cut out between the following multiple terminals and the reference ground: the positive electrode of the battery pack, the second end of the first contactor, the negative electrode of the battery pack, and the second end of the second contactor, wherein the reference ground is used to connect the vehicle body ground; the plurality of switching branches include a first switching branch to a fourth switching branch, and the plurality of switching switches include a first switching switch to a fourth switching switch, wherein: The first switching branch includes a first switching resistor, and the first switching switch is used to control the first switching branch to cut in or cut out between the positive electrode of the battery pack and the reference ground; The second switching branch includes a second switching resistor, and the second switching switch is used to control the second switching branch to cut in or cut out between the negative electrode of the battery pack and the reference ground; The third switching branch includes a third switching resistor, and the third switching switch is used to control the third switching branch to cut in or cut out between the second end of the first contactor and the reference ground; The fourth switching branch includes a fourth switching resistor, and the fourth switching switch is used to control the fourth switching branch to cut in or cut out between the second end of the second contactor and the reference ground; The switching unit further includes a plurality of sampling branches, and the plurality of sampling branches include a first sampling branch and a second sampling branch, The first end of the first sampling branch is connected to the second end of the first switching branch and the second end of the third switching branch; The second end of the second sampling branch is connected to the second end of the second switching branch and the second end of the fourth switching branch; The method includes: The processing unit detects sampling point voltage information of the plurality of switching branches, and the sampling point voltage information is used to indicate the sampling point voltage of the plurality of switching branches; The processing unit determines high-voltage detection information and insulation detection information according to the sampling point voltage information, wherein the high-voltage detection information includes at least one of: a battery pack voltage U bat and a load voltage U load , and the insulation detection information includes at least one of: a positive electrode-to-ground insulation resistance value R p of the battery pack and a negative electrode-to-ground insulation resistance value R n of the battery pack.

14. The method of claim 13, wherein, The method further comprises: The processing unit determines at least one of the following information according to the sampling point voltage information: contact state information of the first contactor, contact state information of the second contactor, wherein the contact state information is used to indicate whether the contact of the contactor is stuck.

15. The method of claim 13, wherein, Each of the plurality of sampling branches comprises an up-sampling resistor and a down-sampling resistor, a first end of each of the up-sampling resistors is connected to a first end of each of the sampling branches, a second end of each of the up-sampling resistors is connected to a first end of the corresponding down-sampling resistor, and a second end of each of the down-sampling resistors is connected to the reference ground, wherein the sampling point voltage of the switching branch is the voltage at the second end of the up-sampling resistor.

16. The method of claim 13, wherein, The processing unit determines high-voltage detection information and insulation detection information according to the sampling point voltage information, comprising: The processing unit controls the plurality of switching switches to be in a first working state, and the first working state is that the first switching switch and the second switching switch are turned on, and the third switching switch and the fourth switching switch are turned off. The processing unit detects the first sampling point voltage U1 of the first switching branch and the second sampling point voltage U2 of the second switching branch when the plurality of switching switches are in the first working state; and The processing unit determines the battery pack voltage U according to the first sampling point voltage U1 and the second sampling point voltage U2 bat .

17. The method of claim 16, wherein, The processing unit determines the battery pack voltage U according to the first sampling point voltage U1 and the second sampling point voltage U2 bat , comprising: the processing unit determines the battery pack voltage U according to the following formula bat : U bat = U p - U n ; U p = U1 x (R1+R 11 +R 12 ) / R 12 ; U n = U2 x (R2 + R 21 + R 22 ) R 22 ; wherein U p represents a positive electrode voltage of the battery pack, U n represents a negative electrode voltage of the battery pack, R1 represents a resistance value of the first switching resistance, R2 represents a resistance value of the second switching resistance, R 11 represents a resistance value of the up-sampling resistance of the first sampling branch, R 12 represents a resistance value of the down-sampling resistance of the first sampling branch, R 21 represents a resistance value of the up-sampling resistance of the second sampling branch, R 22 represents a resistance value of the down-sampling resistance of the second sampling branch.

18. The method of any one of claims 13, 16, or 17, wherein, The processing unit determines high-voltage detection information and insulation detection information according to the sampling point voltage information, comprising: The processing unit controls the plurality of switching switches, the first contactor and the second contactor to be in a second working state, and the second working state is that the first switching switch and the second switching switch are turned off, the third switching switch and the fourth switching switch are turned on, and the first contactor and the second contactor are turned off. The processing unit detects the third sampling point voltage U3 of the third switching branch and the fourth sampling point voltage U4 of the fourth switching branch when the plurality of switching switches, the first contactor and the second contactor are in the second working state; and The processing unit determines the load voltage U according to the third sampling point voltage U3 and the fourth sampling point voltage U4 load .

19. The method of claim 18, wherein, The processing unit determines the load voltage U according to the third sampling point voltage U3 and the fourth sampling point voltage U4 load , comprising: the processing unit determines the load voltage U according to the following formula load : U load = U p ' - U n '; U p ’ = U3 x (R3 + R 11 +R 12 ) / R 12 ; U n ’ = U4 x (R4 + R 21 +R 22 )R 12 ; wherein U p represents a first end voltage of the load, U n represents a second end voltage of the load, R3 represents a resistance value of the third switching resistance, R4 represents a resistance value of the fourth switching resistance, R 11 represents a resistance value of an up-sampling resistance of the first sampling branch, R 12 represents a resistance value of a down-sampling resistance of the first sampling branch, R 21 represents a resistance value of an up-sampling resistance of the second sampling branch, R 22 represents a resistance value of a down-sampling resistance of the second sampling branch.

20. The method of any one of claims 13, 16, or 17, wherein, The processing unit determines high-voltage detection information and insulation detection information according to the sampling point voltage information, comprising: The processing unit controls the plurality of switching switches to be in a first working state, and the first working state is that the first switching switch and the second switching switch are turned on, and the third switching switch and the fourth switching switch are turned off. The processing unit detects the first sampling point voltage U1 of the first switching branch and the second sampling point voltage U2 of the second switching branch when the plurality of switching switches are in the first working state; and The processing unit controls the plurality of switching switches to be in a third working state, and the third working state is that the first switching switch is turned on, and the second switching switch to the fourth switching switch is turned off. The processing unit detects the fifth sampling point voltage U5 of the first switching branch when the plurality of switching switches are in the third working state. The processing unit determines a positive electrode-to-ground insulation resistance value R of the battery pack according to the first sampling point voltage U1, the second sampling point voltage U2, and the fifth sampling point voltage U5 p , a negative electrode-to-ground insulation resistance value R of the battery pack n .

21. The method of claim 20, wherein, The processing unit determines a positive electrode-to-ground insulation resistance value R of the battery pack according to the first sampling point voltage U1, the second sampling point voltage U2, and the fifth sampling point voltage U5 p , a negative electrode-to-ground insulation resistance value R of the battery pack n , comprising: The processing unit determines the positive electrode-to-ground insulation resistance value R of the battery pack according to the following formula p , the negative electrode-to-ground insulation resistance value R of the battery pack n : U p1 / (R p / / (R1+R 11 +R 12 ))=-U n1 / (R n / / (R2+R 21 +R 22 )); U p2 / (R p / / (R1+R 11 +R 12 ))=-U n2 / R n ; U p1 = U1 x (R1+R 11 +R 12 ) / R 12 ; U n1 = U2 x (R2 + R 21 + R 22 ) / R 22 ; U p2 = U5 x (R1+R 11 +R 12 ) / R 12 ; U n2 = U n1 - U p1 + U p2 ; wherein U p1 represents the positive electrode voltage of the battery pack in the first working state, U n1 represents the negative electrode voltage of the battery pack in the first working state, U p2 represents the positive electrode voltage of the battery pack in the third working state, U n2 represents the negative electrode voltage of the battery pack in the third working state, R1 represents the resistance value of the first switching resistance, R2 represents the resistance value of the second switching resistance, R 11 represents the resistance value of the up-sampling resistance of the first sampling branch, R 12 represents the resistance value of the down-sampling resistance of the first sampling branch, R 21 represents the resistance value of the up-sampling resistance of the second sampling branch, R 22 represents the resistance value of the down-sampling resistance of the second sampling branch.

22. The method of any one of claims 13, 16, or 17, wherein, The method further comprises: The processing unit controls the first on-off switch to be turned on, and acquires the voltage U of the first end of the first contactor c1 ; The processing unit controls the third on-off switch to be on, and acquires the voltage U of the second end of the first contactor c2 ; The processing unit determines the actual operating state of the first contactor in dependence on U c1 and U c2 . The processing unit obtains an indicated working state of the first contactor, the indicated working state being a working state of the first contactor indicated by a contactor control signal; The processing unit obtains contact state information of the first contactor according to whether the actual working state and the indicated working state are consistent.

23. The method of any one of claims 13, 16, or 17, wherein, The battery system includes N battery packs, the battery pack being a first battery pack in the N battery packs, and the battery system further includes third to 3N-1 contactors, N≥2; The positive electrode of the i-th battery pack in the N battery packs is connected to a first end of a 3i-3 contactor, a second end of the 3i-3 contactor is used to be connected to a first end of the load, the negative electrode of the i-th battery pack is connected to a first end of a 3i-2 contactor, a second end of the 3i-2 contactor is connected to a second end of the load, and a 3i-1 contactor is arranged between the positive electrode of the i-th battery pack and the negative electrode of the i-1-th battery pack, 2≤i≤N; The plurality of switching switches further includes fifth to 2N+2 switching switches, and the plurality of switching branches further includes fifth to 2N+2 switching branches, wherein, The 2i+1 switching branch includes a 2i+1 switching resistor, and a 2i+1 switching switch is used to control the 2i+1 switching branch to be cut in or cut out between the positive electrode of the i-th battery pack and the reference ground; The 2i+2 switching branch includes a 2i+2 switching resistor, and a 2i+2 switching switch is used to control the 2i+2 switching branch to be cut in or cut out between the negative electrode of the i-th battery pack and the reference ground.

24. The method of claim 23, wherein, The plurality of sampling branches includes a first sampling branch and a second sampling branch, A first end of the first sampling branch is connected to a second end of the 2i+1 switching branch; A first end of the second sampling branch is connected to a second end of the 2i+2 switching branch.

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