High-voltage BMS insulation calibration and detection system and insulation calibration and detection method

Abstract

The invention discloses a high-voltage BMS insulation calibration and detection system and an insulation calibration and detection method, and relates to the technical field of battery management systems, the system comprises a circuit assembly and a control assembly, the circuit assembly comprises a third divider resistor, a fourth divider resistor, a fifth divider resistor and a sixth divider resistor which are connected in series, the third divider resistor and the fourth divider resistor are connected in parallel with a first variable resistor, one end of the third divider resistor and one end of the fourth divider resistor are connected to the positive electrode of a high-voltage power supply through a first isolation switch, and the other end of the fourth divider resistor is grounded through a second isolation switch. The fifth divider resistor and the sixth divider resistor are connected in parallel with a second variable resistor, and one end of the fifth divider resistor and one end of the sixth divider resistor are grounded through the second isolation switch. And the third divider resistor and the fourth divider resistor are connected to the negative electrode of the high-voltage power supply through a third isolating switch. The detection precision of the insulation resistance of the high-voltage power supply can be improved, and the risk of fault false alarm is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of battery management systems, and in particular to a high-voltage BMS insulation calibration and detection system and an insulation calibration and detection method. Background Art

[0002] With the rapid development of electric vehicles, the battery management system has become one of the core systems of electric vehicles. The insulation performance of the battery pack is related to the safety of electric vehicles. Therefore, the battery management system (BMS) is of great significance for the insulation detection of the battery pack.

[0003] Currently, most methods use balanced bridges and unbalanced bridges to detect the insulation resistance of battery packs. However, under high voltage conditions, the resistance value of the resistor in the insulation detection circuit will drift due to external environmental influences, such as temperature. A small drift in the detection circuit will lead to a large deviation in the insulation resistance measurement, which poses a risk of false alarm of insulation faults and affects the customer experience. Summary of the Invention

[0004] The present application provides a high-voltage BMS insulation calibration and detection system and an insulation calibration and detection method, which can improve the detection accuracy of the insulation resistance of the high-voltage power supply and reduce the risk of false fault alarms.

[0005] In a first aspect, an embodiment of the present application provides a high-voltage BMS insulation calibration and detection system, the high-voltage BMS insulation calibration and detection system comprising:

[0006] A circuit assembly comprising a third voltage-dividing resistor, a fourth voltage-dividing resistor, a fifth voltage-dividing resistor, and a sixth voltage-dividing resistor connected in series, wherein the third and fourth voltage-dividing resistors are connected in parallel with a first variable resistor, one end of which is connected to the positive electrode of the high-voltage power supply via a first isolating switch, and the other end is grounded via a second isolating switch; the fifth and sixth voltage-dividing resistors are connected in parallel with a second variable resistor, one end of which is grounded via a second isolating switch, and the other end is connected to the negative electrode of the high-voltage power supply; and the third and fourth voltage-dividing resistors are connected to the negative electrode of the high-voltage power supply via a third isolating switch;

[0007] The control component includes a control module, an isolation ADC module and a control host computer. The control module is used to control the opening and closing of the first isolation switch, the second isolation switch, and the third isolation switch, as well as the resistance values of the first variable resistor and the second variable resistor. The isolation ADC module is used to collect the voltage between the first variable resistor and the first isolation switch, and the voltage between the fifth voltage divider resistor and the sixth voltage divider resistor.

[0008] In conjunction with the first aspect, in one embodiment,

[0009] The control component further includes a storage module, which is used for storing data;

[0010] The control host computer is used to send control instructions to the control module so that the control module performs corresponding control operations.

[0011] In a second aspect, an embodiment of the present application provides an insulation calibration method for a high-voltage BMS, which is implemented based on the above-mentioned system. The insulation calibration method for the high-voltage BMS includes:

[0012] Controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first and second variable resistors, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors;

[0013] Controlling the first isolating switch, the second isolating switch, and the third isolating switch to be closed, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor again;

[0014] Controlling the first isolating switch and the second isolating switch to be closed and the third isolating switch to be open, resetting the resistance values of the first variable resistor and the second variable resistor, and recollecting the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor;

[0015] Controlling the first isolating switch, the second isolating switch, and the third isolating switch to be closed, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor again;

[0016] Based on the set resistance value of the variable resistor and the collected voltage, a theoretical value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor during each collection operation is calculated;

[0017] A linear fit is performed using the theoretical value and the collected value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor to obtain a fitting coefficient, and whether the insulation calibration is successful is determined based on the fitting coefficient.

[0018] In conjunction with the second aspect, in one embodiment, controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first and second variable resistors, collecting the high-voltage power supply output voltage and the voltage between the fifth and sixth voltage-dividing resistors, controlling the first, second, and third isolating switches to close, and again collecting the high-voltage power supply output voltage and the voltage between the fifth and sixth voltage-dividing resistors, specifically includes:

[0019] Control the host computer to control the high-voltage power supply to output a specific voltage V0, and control the host computer to send a first calibration instruction to the control module through the CAN bus;

[0020] The control module receives the first calibration instruction, controls the first isolating switch and the second isolating switch to be closed, and the third isolating switch to be open, and controls the resistance of the first variable resistor to be R 11 , the resistance of the second variable resistor is R 21 ;

[0021] The control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply 01 , and the voltage V between the fifth and sixth voltage-dividing resistors r1 ;

[0022] The control module controls the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the control module controls the isolation ADC module to collect the output voltage V of the high-voltage power supply. 02 , and the voltage V between the fifth and sixth voltage-dividing resistors r2 ;

[0023] The control module feeds back the execution result of the first calibration instruction to the control host computer through the CAN bus, and the control host computer sends the second calibration instruction to the control module or sends the first calibration instruction to the control module again based on the execution result of the first calibration instruction.

[0024] In conjunction with the second aspect, in one embodiment, controlling the first and second isolating switches to close and the third isolating switch to open, resetting the resistance values of the first and second variable resistors, and recollecting the high-voltage power supply output voltage and the voltage between the fifth and sixth voltage-dividing resistors, controlling the first, second, and third isolating switches to close, and recollecting the high-voltage power supply output voltage and the voltage between the fifth and sixth voltage-dividing resistors, specifically includes:

[0025] The control module receives the second calibration instruction, controls the first isolating switch and the second isolating switch to be closed, and the third isolating switch to be open, and controls the resistance of the first variable resistor to be R 12 , the resistance of the second variable resistor is R 22 ;

[0026] The control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply 03 , and the voltage V between the fifth and sixth voltage-dividing resistors r3 ;

[0027] The control module controls the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the control module controls the isolation ADC module to collect the output voltage V of the high-voltage power supply. 04 , and the voltage V between the fifth and sixth voltage-dividing resistors r4 .

[0028] In conjunction with the second aspect, in one embodiment,

[0029] The step of calculating the theoretical value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor during each acquisition operation based on the set resistance value of the variable resistor and the acquired voltage specifically includes:

[0030] The control module uses the resistor voltage divider principle based on the set resistance value R of the variable resistor. 11 、R 21 、R 12 、R 22 , and the output voltage V of the high-voltage power supply corresponding to each acquisition operation of the isolation ADC module 01 、V 02 、V 03 、V 04 , the corresponding calculation is to obtain the theoretical value V of the voltage between the fifth and sixth voltage divider resistors during each acquisition operation of the isolated ADC module. f1 、V f2 、V f3 、V f4 , specifically,

[0031]

[0032]

[0033] Wherein, R3 represents the resistance value of the third voltage-dividing resistor, R4 represents the resistance value of the fourth voltage-dividing resistor, R5 represents the resistance value of the fifth voltage-dividing resistor, and R6 represents the resistance value of the sixth voltage-dividing resistor;

[0034] The method of performing linear fitting using the theoretical value and the collected value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor to obtain a fitting coefficient and determining whether the insulation calibration is successful based on the fitting coefficient specifically includes:

[0035] A linear fit is performed between the collected value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor and the corresponding theoretical value to obtain a fitting coefficient. Specifically,

[0036]

[0037] B1=V r3 -K1*V f3

[0038]

[0039] B2=V r4 -K2*V f4

[0040] Among them, K1, K2, B1, and B2 represent fitting coefficients;

[0041] Determine whether K1 and K2 are both within the preset range. If so, it means that the insulation calibration is successful, and K1, K2, B1, and B2 are stored. If not, it means that the insulation calibration fails, and the insulation calibration method of the high-voltage BMS is executed again.

[0042] In a third aspect, the present application provides a high-voltage BMS insulation detection method in real time, which is implemented based on the above method. The high-voltage BMS insulation detection method includes:

[0043] Controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first and second variable resistors, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors;

[0044] Controlling the first isolating switch, the second isolating switch, and the third isolating switch to be closed, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor again;

[0045] Based on the stored K1, K2, B1, and B2, the collected voltage between the fifth and sixth voltage-dividing resistors is corrected, and based on Kirchhoff's current law, the resistance values of the positive and negative insulation resistances of the high-voltage power supply are calculated;

[0046] The calculated positive electrode insulation resistance value is compared with the set first variable resistor value, and the negative electrode insulation resistance value is compared with the set second variable resistor value. Based on the comparison error, it is determined whether the insulation test has passed.

[0047] In conjunction with the third aspect, in one embodiment, controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first and second variable resistors, collecting the high-voltage power supply output voltage and the voltage between the fifth and sixth voltage-dividing resistors, controlling the first, second, and third isolating switches to close, and again collecting the high-voltage power supply output voltage and the voltage between the fifth and sixth voltage-dividing resistors, specifically includes:

[0048] The host computer controls the high-voltage power supply to output a specific voltage V1, and the host computer sends an insulation detection instruction to the control module through the CAN bus;

[0049] The control module receives the insulation detection instruction, controls the first and second isolating switches to be closed, the third isolating switch to be open, and controls the resistance of the first variable resistor to be R 011 , the resistance of the second variable resistor is R 021 ;

[0050] The control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply 001 , and the voltage V between the fifth and sixth voltage-dividing resistors 0r1 ;

[0051] The control module controls the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the control module controls the isolation ADC module to collect the output voltage V of the high-voltage power supply. 002 , and the voltage V between the fifth and sixth voltage-dividing resistors 0r2 .

[0052] In conjunction with the third aspect, in one embodiment, the voltage between the fifth and sixth voltage-dividing resistors is corrected based on the stored K1, K2, B1, and B2, and the resistance of the positive and negative insulation resistances of the high-voltage power supply are calculated based on Kirchhoff's current law, specifically including:

[0053] Based on the stored K1, K2, B1, B2, the voltage V between the fifth and sixth voltage-dividing resistors is collected. 0r1 、V 0r2 Make corrections, specifically:

[0054] V 0r1 ′=K1*V 0r1 +B1

[0055] V 0r2 ′=K2*V 0r2 +B2

[0056] Among them, V 0r1 ′ represents V 0r1 Corrected voltage value, V 0r2 ′ represents V 0r2 Corrected voltage value;

[0057] Based on Kirchhoff's current law, the resistance of the positive and negative insulation resistances of the high-voltage power supply are calculated. Specifically,

[0058]

[0059] V p1 =V 001 -V n1

[0060]

[0061] V p1 =V 002 -V n2

[0062]

[0063] Among them, R 011 ' represents the calculated insulation resistance of the positive electrode of the high voltage power supply, R 021 ' represents the calculated insulation resistance of the negative electrode of the high voltage power supply, V p1 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 001 When the voltage between the positive electrode of the high voltage power supply and the ground is V n1 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 001 When the voltage between the negative electrode of the high voltage power supply and the ground is V p2 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 002 When the voltage between the positive electrode of the high voltage power supply and the ground is V n2 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 002 When , the voltage between the negative pole of the high voltage power supply and the ground.

[0064] In conjunction with the third aspect, in one embodiment, comparing the calculated positive electrode insulation resistance value with the set first variable resistor value, and comparing the negative electrode insulation resistance value with the set second variable resistor value, and judging whether the insulation test passes based on the comparison error, specifically includes:

[0065] R 011 ′ and R 011 Compare and R 021 ′ and R 021 A comparison is performed. If the errors are all within the preset percentage range, it means that the insulation test has passed. Otherwise, it means that the insulation test has failed, and the insulation test method of the high-voltage BMS is executed again.

[0066] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0067] Through circuit components and control components, the host computer is controlled to send calibration instructions and insulation detection instructions to the control module. The control module controls the high-voltage power supply to output the specified voltage according to the received instructions, controls the opening and closing of the isolation switch, sets the resistance value of the variable resistor, and obtains the collected voltage value from the isolation ADC module. By performing different operations, insulation calibration and insulation detection are completed. Insulation calibration and insulation detection reuse the same circuit, reducing unnecessary devices and lowering circuit costs. At the same time, insulation calibration improves the accuracy of insulation detection, reduces the false alarm rate of insulation faults, ensures the safety of the battery management system, and enhances user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 This is a schematic diagram of the structure of the high-voltage BMS insulation calibration and detection system for this application;

[0069] Figure 2 A flow chart of the insulation calibration method for a high-voltage BMS in this application;

[0070] Figure 3 This is a flow chart of the insulation detection method for a high-voltage BMS in this application. DETAILED DESCRIPTION

[0071] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0072] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0073] On the one hand, the embodiments of the present application provide a high-voltage BMS insulation calibration and detection system for detecting high-voltage power supplies, which can improve the detection accuracy of the insulation resistance of the high-voltage power supply and reduce the risk of false fault alarms.

[0074] In one embodiment, referring to Figure 1 , Figure 1 This is a schematic diagram of the structure of the high-voltage BMS insulation calibration and detection system for this application. Figure 1 As shown, the high-voltage BMS insulation calibration and detection system includes: a circuit component and a control component.

[0075] The circuit component includes a third voltage-dividing resistor, a fourth voltage-dividing resistor, a fifth voltage-dividing resistor, and a sixth voltage-dividing resistor connected in series. After the first variable resistor is connected in parallel to the third voltage-dividing resistor and the fourth voltage-dividing resistor, one end is connected to the positive pole of the high-voltage power supply through the first isolating switch, and the other end is grounded through the second isolating switch. After the second variable resistor is connected in parallel to the fifth voltage-dividing resistor and the sixth voltage-dividing resistor, one end is grounded through the second isolating switch, and the other end is connected to the negative pole of the high-voltage power supply. The third voltage-dividing resistor and the fourth voltage-dividing resistor are connected to the negative pole of the high-voltage power supply through the third isolating switch.

[0076] Figure 1 In the figure, R1 represents the first variable resistor, R2 represents the second variable resistor, R3 represents the third voltage-dividing resistor, R4 represents the fourth voltage-dividing resistor, R5 represents the fifth voltage-dividing resistor, R6 represents the sixth voltage-dividing resistor, SW1 represents the first isolating switch, SW2 represents the second isolating switch, SW3 represents the third isolating switch, and the high-voltage power supply in this application is a power supply with controllable output voltage, and the output voltage range is 0 to 800V.

[0077] See also Figure 1 As shown, R3, R4, R5, and R6 are connected in series, R1 is connected in parallel to R3 and R4, one end of R1 is connected to the positive electrode of the high-voltage power supply through SW1, and the other end of R1 is grounded through SW2, R2 is connected in parallel to R5 and R6, one end of R2 is grounded through SW2, and the other end is connected to the negative electrode of the high-voltage power supply, and the connection point between R3 and R4 is connected to the negative electrode of the high-voltage power supply through SW3.

[0078] The control component includes a control module, an isolated ADC (Analog-to-Digital Converter) module, and a control host computer. The control module is used to control the opening and closing of the first, second, and third isolation switches, as well as the resistance values of the first and second variable resistors. The isolated ADC module is used to collect the voltage between the first variable resistor and the first isolation switch, and the voltage between the fifth and sixth voltage-dividing resistors. The control component also includes a storage module for data storage. The control host computer is used to send control instructions to the control module to enable the control module to perform corresponding control operations.

[0079] Specifically, the voltage output of the high-voltage power supply can be controlled by controlling the host computer. The isolated ADC module provides at least two ADC acquisition channels (the sampling accuracy must be within 1mV, and the higher the accuracy, the better). One ADC acquisition channel is used to collect the voltage at the connection point between the first variable resistor and the first isolation switch, and one ADC acquisition channel is used to collect the resistance at the connection point between the fifth voltage divider resistor and the sixth voltage divider; the control module receives instructions sent by the control host computer, controls the conduction and closing of the first isolation switch, the second isolation switch, and the third isolation switch, and at the same time receives the sampling values collected by the isolated ADC module, and performs different operations according to the different states of the current control module; the storage module stores the results of insulation calibration, and the results will not be lost after power failure. After power is restored, the control module will read the calibration data from the storage module; the control host computer sends different control instructions to the control module through the CAN bus, and the control module performs corresponding operations after receiving the instructions.

[0080] In a second aspect, an embodiment of the present application further provides an insulation calibration method for a high-voltage BMS, which is implemented based on the above-mentioned high-voltage BMS insulation calibration and detection system.

[0081] In one embodiment, referring to Figure 2 , Figure 2 This is a flow chart of the insulation calibration method for the high-voltage BMS in this application. Figure 2 As shown, the insulation calibration method of the high-voltage BMS includes:

[0082] S11: Controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first and second variable resistors, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors;

[0083] S12: Control the first isolating switch, the second isolating switch, and the third isolating switch to be closed, and collect the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor again;

[0084] S13: Controlling the first isolating switch and the second isolating switch to be closed, and the third isolating switch to be opened, and resetting the resistance values of the first variable resistor and the second variable resistor, and re-collecting the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor;

[0085] S14: Control the first isolating switch, the second isolating switch, and the third isolating switch to be closed, and collect the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor again;

[0086] S15: Calculating a theoretical value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor during each acquisition operation based on the set resistance value of the variable resistor and the collected voltage;

[0087] S16: Perform linear fitting using the theoretical value and the collected value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor to obtain a fitting coefficient, and determine whether the insulation calibration is successful based on the fitting coefficient.

[0088] Furthermore, in one embodiment, controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first and second variable resistors, collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors, controlling the first, second, and third isolating switches to close, and again collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors, specifically includes:

[0089] a1: Control the host computer to control the high-voltage power supply to output a specific voltage V0, generally 400V to 600V, and control the host computer to send the first calibration command to the control module through the CAN bus;

[0090] a2: The control module receives the first calibration instruction, controls the first and second isolating switches to be closed, and the third isolating switch to be open, and controls the resistance of the first variable resistor to be R 11 , the resistance of the second variable resistor is R 21It should be noted that when controlling the resistance of the variable resistor, the resistance of the current variable resistor can be controlled to a value based on experience. If there is a subsequent cycle, the resistance of the current variable resistor is adjusted in the next cycle. 11 Generally, it is several hundred KΩ level, R 21 Generally, it is several MΩ level, R 21 Generally R 11 ten times of

[0091] a3: The control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply 01 , and the voltage V between the fifth and sixth voltage-dividing resistors r1 ;

[0092] a4: The control module controls the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply. 02 , and the voltage V between the fifth and sixth voltage-dividing resistors r2 ;

[0093] a5: The control module feeds back the execution result of the first calibration instruction to the control host computer via the CAN bus. Based on the execution result of the first calibration instruction, the control host computer sends a second calibration instruction to the control module or sends the first calibration instruction to the control module again. That is, the control module feeds back the execution result of the first calibration instruction to the control host computer via the CAN bus. If the execution result is failure, the control host computer sends the first calibration instruction to the control module again, and steps a1 to a5 above are executed again. If the execution result is failure, the control host computer sends a second calibration instruction to the control module.

[0094] Furthermore, in one embodiment, controlling the first and second isolating switches to be closed and the third isolating switch to be open, resetting the resistance values of the first and second variable resistors, and again collecting the high-voltage power supply output voltage and the voltage between the fifth and sixth voltage-dividing resistors, controlling the first, second, and third isolating switches to be closed, and again collecting the high-voltage power supply output voltage and the voltage between the fifth and sixth voltage-dividing resistors, specifically includes:

[0095] a6: The control module receives the second calibration instruction, controls the first and second isolating switches to be closed, the third isolating switch to be open, and controls the resistance of the first variable resistor to be R 12 , the resistance of the second variable resistor is R 22 ; Among them, R 12 Generally, it is several MΩ level, R 22 Generally, it is several hundred KΩ level, R 12 Generally R 22 ten times of

[0096] a7: The control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply 03 , and the voltage V between the fifth and sixth voltage-dividing resistors r3 ;

[0097] a8: The control module controls the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply. 04 , and the voltage V between the fifth and sixth voltage-dividing resistors r4 .

[0098] Furthermore, in one embodiment, based on the set resistance value of the variable resistor and the collected voltage, a theoretical value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor during each collection operation is calculated, specifically including:

[0099] a9: The control module uses the resistor voltage divider principle based on the set resistance value R of the variable resistor 11 、R 21 、R 12 、R 22 , and the output voltage V of the high-voltage power supply corresponding to each acquisition operation of the isolation ADC module 01 、V 02 、V 03 、V 04 , the corresponding calculation is to obtain the theoretical value V of the voltage between the fifth and sixth voltage divider resistors during each acquisition operation of the isolated ADC module. f1 、V f2 、V f3 、V f4 , specifically,

[0100]

[0101]

[0102] Wherein, R3 represents the resistance value of the third voltage-dividing resistor, R4 represents the resistance value of the fourth voltage-dividing resistor, R5 represents the resistance value of the fifth voltage-dividing resistor, and R6 represents the resistance value of the sixth voltage-dividing resistor;

[0103] It should be noted that V f1 Indicates the output voltage V of the isolated ADC module when the high voltage power supply is 01 During acquisition, the theoretical value of the voltage between the fifth and sixth voltage divider resistors, V f2 Indicates the output voltage V of the isolated ADC module when the high voltage power supply is 02 During acquisition, the theoretical value of the voltage between the fifth and sixth voltage divider resistors, V f3Indicates the output voltage V of the isolated ADC module when the high voltage power supply is 03 During acquisition, the theoretical value of the voltage between the fifth and sixth voltage divider resistors, V f4 Indicates the output voltage V of the isolated ADC module when the high voltage power supply is 04 The theoretical value of the voltage between the fifth and sixth voltage-dividing resistors during acquisition.

[0104] Furthermore, in one embodiment, a linear fit is performed using the theoretical value and the collected value of the voltage between the fifth and sixth voltage-dividing resistors to obtain a fitting coefficient. The success of the insulation calibration is determined based on the fitting coefficient, specifically including:

[0105] a10: Perform linear fitting between the collected value of the voltage between the fifth and sixth voltage-dividing resistors and the corresponding theoretical value to obtain the fitting coefficient. Specifically,

[0106]

[0107] B1=V r3 -K1*V f3

[0108]

[0109] B2=V r4 -K2*V f4

[0110] Among them, K1, K2, B1, and B2 represent fitting coefficients;

[0111] Specifically, based on the linear fitting formula Y=K*X+B, the collected value and theoretical value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor are used for fitting to obtain the above-mentioned K1, K2, B1, and B2.

[0112] a11: Determine whether K1 and K2 are both within the preset range. If so, it means that the insulation calibration is successful, and K1, K2, B1, and B2 are stored. If not, it means that the insulation calibration fails, and the insulation calibration method of the high-voltage BMS is executed again.

[0113] Specifically, the control module determines whether K1 and K2 are both within a preset range, which can be 0.9 to 1.1. If so, the insulation calibration is successful and the values of K1, K2, B1, and B2 are stored in the storage module. Otherwise, the insulation calibration is poor and has failed. The control module then feeds back the execution result of the second calibration instruction to the control host computer via the CAN bus. If the execution result is successful, the insulation calibration is successful and the calibration process is exited. If the execution result is unsuccessful, the insulation calibration has failed and steps a1 to a11 above are executed again.

[0114] In a third aspect, an embodiment of the present application further provides an insulation detection method for a high-voltage BMS, which is implemented based on the insulation calibration method for the high-voltage BMS described above.

[0115] In one embodiment, referring to Figure 3 , Figure 3 This is a flow chart of the insulation detection method for high-voltage BMS in this application. Figure 3 As shown, the insulation detection methods for high-voltage BMS include:

[0116] S21: Control the high-voltage power supply to output a specific voltage, close the first and second isolating switches, and open the third isolating switch, set the resistance values of the first and second variable resistors, and collect the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors;

[0117] S22: Control the first isolating switch, the second isolating switch, and the third isolating switch to be closed, and collect the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor again;

[0118] S23: Based on the stored K1, K2, B1, and B2, the collected voltage between the fifth and sixth voltage-dividing resistors is corrected, and based on Kirchhoff's current law, the resistance values of the positive and negative insulation resistances of the high-voltage power supply are calculated;

[0119] S24: Compare the calculated positive electrode insulation resistance value with the set first variable resistor value, and compare the negative electrode insulation resistance value with the set second variable resistor value, and determine whether the insulation test passes based on the comparison error.

[0120] Furthermore, in one embodiment, controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first and second variable resistors, collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors, controlling the first, second, and third isolating switches to close, and again collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors, specifically includes:

[0121] b1: Control the host computer to control the high-voltage power supply to output a specific voltage V1, generally 400V to 600V, and control the host computer to send insulation detection instructions to the control module through the CAN bus;

[0122] b2: The control module receives the insulation detection instruction, controls the first and second isolating switches to be closed, the third isolating switch to be open, and controls the resistance of the first variable resistor to be R 011 , the resistance of the second variable resistor is R 021 ; R 011 and R021 They are all relatively large values, generally hundreds of megohms;

[0123] b3: The control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply 001 , and the voltage V between the fifth and sixth voltage-dividing resistors 0r1 ;

[0124] b4: The control module controls the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply. 002 , and the voltage V between the fifth and sixth voltage-dividing resistors 0r2 .

[0125] Furthermore, in one embodiment, based on the stored K1, K2, B1, and B2, the collected voltage between the fifth and sixth voltage-dividing resistors is corrected, and based on Kirchhoff's current law, the resistance value of the positive electrode insulation resistance and the resistance value of the negative electrode insulation resistance of the high-voltage power supply are calculated, specifically including:

[0126] b5: Based on the stored K1, K2, B1, and B2, the voltage V between the fifth and sixth voltage-dividing resistors is collected. 0r1 、V 0r2 Make corrections, specifically:

[0127] V 0r1 ′=K1*V 0r1 +B1

[0128] V 0r2 ′=K2*V 0r2 +B2

[0129] Among them, V 0r1 ′ represents V 0r1 Corrected voltage value, V 0r2 ′ represents V 0r2 Corrected voltage value; that is, from 7) the control module reads the stored K1, K2, B1, B2 from the storage module, and then V 0r1 、V 0r2 Make corrections;

[0130] b6: Based on Kirchhoff's current law, calculate the insulation resistance of the positive electrode and the insulation resistance of the negative electrode of the high voltage power supply. Specifically,

[0131]

[0132] V p1 =V 001 -V n1

[0133]

[0134] V p1 =V 002 -V n2

[0135]

[0136] Among them, R 011 ' represents the calculated insulation resistance of the positive electrode of the high voltage power supply, R 021 ' represents the calculated insulation resistance of the negative electrode of the high voltage power supply, V p1 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 001 When the voltage between the positive electrode of the high voltage power supply and the ground is V n1 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 001 When the voltage between the negative electrode of the high voltage power supply and the ground is V p2 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 002 When the voltage between the positive electrode of the high voltage power supply and the ground is V n2 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 002 When , the voltage between the negative pole of the high voltage power supply and the ground.

[0137] Furthermore, in one embodiment, the calculated positive electrode insulation resistance value is compared with the set first variable resistor value, and the negative electrode insulation resistance value is compared with the set second variable resistor value. Based on the comparison error, whether the insulation test passes is determined, specifically including:

[0138] b7: R 011 ′ and R 011 Compare and R 021 ′ and R 021 A comparison is performed. If the errors are all within the preset percentage range, it means that the insulation test has passed. Otherwise, it means that the insulation test has failed, and the insulation test method of the high-voltage BMS is executed again.

[0139] Specifically, R 011 ′ and R 011 Compare and R 021 ′ and R 021 Compare, if R 011 ′ and R 011 Inter-error, R 021 ′ and R 021If the errors between the insulation test pieces are within a preset percentage range, which may be within 10%, the insulation test passes. Otherwise, the insulation test fails. The control module feeds back the insulation test results to the control host computer via the CAN bus. If the insulation test fails, the above steps b1 to b7 are executed again.

[0140] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0141] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0142] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0143] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0144] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0145] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A high voltage BMS insulation calibration and detection system, characterized in that: The high-voltage BMS insulation calibration and detection system includes: A circuit assembly comprising a third voltage-dividing resistor, a fourth voltage-dividing resistor, a fifth voltage-dividing resistor, and a sixth voltage-dividing resistor connected in series, wherein the third and fourth voltage-dividing resistors are connected in parallel with a first variable resistor, one end of which is connected to the positive electrode of the high-voltage power supply via a first isolating switch, and the other end is grounded via a second isolating switch; the fifth and sixth voltage-dividing resistors are connected in parallel with a second variable resistor, one end of which is grounded via a second isolating switch, and the other end is connected to the negative electrode of the high-voltage power supply; and the third and fourth voltage-dividing resistors are connected to the negative electrode of the high-voltage power supply via a third isolating switch; The control component includes a control module, an isolation ADC module and a control host computer. The control module is used to control the opening and closing of the first isolation switch, the second isolation switch, and the third isolation switch, as well as the resistance values of the first variable resistor and the second variable resistor. The isolation ADC module is used to collect the voltage between the first variable resistor and the first isolation switch, and the voltage between the fifth voltage divider resistor and the sixth voltage divider resistor.

2. A high-voltage BMS insulation calibration and detection system according to claim 1, characterized in that: The control component further includes a storage module, which is used for storing data; The control host computer is used to send control instructions to the control module so that the control module performs corresponding control operations.

3. A method for insulation calibration of a high-voltage BMS, implemented based on the system of claim 1 or 2, characterized in that: The insulation calibration method of the high-voltage BMS includes: Controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first and second variable resistors, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors; Controlling the first isolating switch, the second isolating switch, and the third isolating switch to be closed, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor again; Controlling the first isolating switch and the second isolating switch to be closed and the third isolating switch to be open, resetting the resistance values of the first variable resistor and the second variable resistor, and recollecting the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor; Controlling the first isolating switch, the second isolating switch, and the third isolating switch to be closed, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor again; Based on the set resistance value of the variable resistor and the collected voltage, a theoretical value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor during each collection operation is calculated; A linear fit is performed using the theoretical value and the collected value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor to obtain a fitting coefficient, and whether the insulation calibration is successful is determined based on the fitting coefficient.

4. The insulation calibration method of a high-voltage BMS according to claim 3, characterized in that: The method of controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first variable resistor and the second variable resistor, collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors, controlling the first, second, and third isolating switches to close, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors again, specifically includes: Control the host computer to control the high-voltage power supply to output a specific voltage V0, and control the host computer to send a first calibration instruction to the control module through the CAN bus; The control module receives the first calibration instruction, controls the first isolating switch and the second isolating switch to be closed, and the third isolating switch to be open, and controls the resistance of the first variable resistor to be R 11 , the resistance of the second variable resistor is R 21 ; The control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply 01 , and the voltage V between the fifth and sixth voltage-dividing resistors r1 ; The control module controls the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the control module controls the isolation ADC module to collect the output voltage V of the high-voltage power supply. 02 , and the voltage V between the fifth and sixth voltage-dividing resistors r2 ; The control module feeds back the execution result of the first calibration instruction to the control host computer through the CAN bus, and the control host computer sends the second calibration instruction to the control module or sends the first calibration instruction to the control module again based on the execution result of the first calibration instruction.

5. The insulation calibration method of a high-voltage BMS according to claim 4, characterized in that: The controlling of the first isolating switch and the second isolating switch to be closed and the third isolating switch to be opened, and the resistance values of the first variable resistor and the second variable resistor to be set again, and the high-voltage power supply output voltage and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor to be collected again, and the controlling of the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the high-voltage power supply output voltage and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor to be collected again, specifically includes: The control module receives the second calibration instruction, controls the first isolating switch and the second isolating switch to be closed, and the third isolating switch to be open, and controls the resistance of the first variable resistor to be R 12 , the resistance of the second variable resistor is R 22 ; The control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply 03 , and the voltage V between the fifth and sixth voltage-dividing resistors r3 ; The control module controls the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the control module controls the isolation ADC module to collect the output voltage V of the high-voltage power supply. 04 , and the voltage V between the fifth and sixth voltage-dividing resistors r4 .

6. The insulation calibration method of a high-voltage BMS according to claim 5, characterized in that: The step of calculating the theoretical value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor during each acquisition operation based on the set resistance value of the variable resistor and the acquired voltage specifically includes: The control module uses the resistor voltage divider principle based on the set resistance value R of the variable resistor. 11 、R 21 、R 12 、R 22 , and the output voltage V of the high-voltage power supply corresponding to each acquisition operation of the isolation ADC module 01 、V 02 、V 03 、V 04 , the corresponding calculation is to obtain the theoretical value V of the voltage between the fifth and sixth voltage divider resistors during each acquisition operation of the isolated ADC module. f1 、V f2 、V f3 、V f4 , specifically, Wherein, R3 represents the resistance value of the third voltage-dividing resistor, R4 represents the resistance value of the fourth voltage-dividing resistor, R5 represents the resistance value of the fifth voltage-dividing resistor, and R6 represents the resistance value of the sixth voltage-dividing resistor; The method of performing linear fitting using the theoretical value and the collected value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor to obtain a fitting coefficient and judging whether the insulation calibration is successful based on the fitting coefficient specifically includes: A linear fit is performed between the collected value of the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor and the corresponding theoretical value to obtain a fitting coefficient. Specifically, B1=V r3 -K1*V f3 B2=V r4 -K2*V f4 Among them, K1, K2, B1, and B2 represent fitting coefficients; Determine whether K1 and K2 are both within the preset range. If so, it means that the insulation calibration is successful, and K1, K2, B1, and B2 are stored. If not, it means that the insulation calibration fails, and the insulation calibration method of the high-voltage BMS is executed again.

7. A method for insulation detection of a high-voltage BMS, implemented based on the method of claim 6, characterized in that: The insulation detection method of the high-voltage BMS includes: Controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first and second variable resistors, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors; Controlling the first isolating switch, the second isolating switch, and the third isolating switch to be closed, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth voltage-dividing resistor and the sixth voltage-dividing resistor again; Based on the stored K1, K2, B1, and B2, the collected voltage between the fifth and sixth voltage-dividing resistors is corrected, and based on Kirchhoff's current law, the resistance values of the positive and negative insulation resistances of the high-voltage power supply are calculated; The calculated positive electrode insulation resistance value is compared with the set first variable resistor value, and the negative electrode insulation resistance value is compared with the set second variable resistor value. Based on the comparison error, it is determined whether the insulation test has passed.

8. The insulation detection method of a high-voltage BMS according to claim 7, characterized in that: The method of controlling the high-voltage power supply to output a specific voltage, closing the first and second isolating switches, and opening the third isolating switch, setting the resistance values of the first variable resistor and the second variable resistor, collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors, controlling the first, second, and third isolating switches to close, and collecting the output voltage of the high-voltage power supply and the voltage between the fifth and sixth voltage-dividing resistors again, specifically includes: The host computer controls the high-voltage power supply to output a specific voltage V1, and the host computer sends an insulation detection instruction to the control module through the CAN bus; The control module receives the insulation detection instruction, controls the first and second isolating switches to be closed, the third isolating switch to be open, and controls the resistance of the first variable resistor to be R 011 , the resistance of the second variable resistor is R 021 ; The control module controls the isolated ADC module to collect the output voltage V of the high-voltage power supply 001 , and the voltage V between the fifth and sixth voltage-dividing resistors 0r1 ; The control module controls the first isolating switch, the second isolating switch and the third isolating switch to be closed, and the control module controls the isolation ADC module to collect the output voltage V of the high-voltage power supply. 002 , and the voltage V between the fifth and sixth voltage-dividing resistors 0r2 .

9. The insulation detection method of a high-voltage BMS according to claim 8, characterized in that: The method of correcting the collected voltage between the fifth and sixth voltage-dividing resistors based on the stored K1, K2, B1, and B2, and calculating the resistance of the positive and negative insulation resistances of the high-voltage power supply based on Kirchhoff's current law, specifically includes: Based on the stored K1, K2, B1, B2, the voltage V between the fifth and sixth voltage-dividing resistors is collected. 0r1 、V 0r2 Make corrections, specifically: In 0r1 ′=K1*V 0r1 +B1 V 0r2 ′=K2*V 0r2 +B2 Among them, V 0r1 ′ represents V 0r1 Corrected voltage value, V 0r2 ′ represents V 0r2 Corrected voltage value; Based on Kirchhoff's current law, the resistance of the positive and negative insulation resistances of the high-voltage power supply are calculated. Specifically, V p1 =V 001 -V n1 V p1 =V 002 -V n2 Among them, R 011 ' represents the calculated insulation resistance of the positive electrode of the high voltage power supply, R 021 ' represents the calculated insulation resistance of the negative electrode of the high voltage power supply, V p1 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 001 When the voltage between the positive electrode of the high voltage power supply and the ground is V n1 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 001 When the voltage between the negative electrode of the high voltage power supply and the ground is V p2 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 002 When the voltage between the positive electrode of the high voltage power supply and the ground is V n2 Indicates that the isolated ADC module collects the output voltage V of the high-voltage power supply 002 When , the voltage between the negative pole of the high voltage power supply and the ground.

10. The insulation detection method of a high-voltage BMS according to claim 9, characterized in that: The calculated positive electrode insulation resistance value is compared with the set first variable resistance value, and the negative electrode insulation resistance value is compared with the set second variable resistance value, and based on the comparison error, whether the insulation test is passed is determined, specifically including: R 011 ′ and R 011 Compare and R 021 ′ and R 021 A comparison is performed. If the errors are all within the preset percentage range, it means that the insulation test has passed. Otherwise, it means that the insulation test has failed, and the insulation test method of the high-voltage BMS is executed again.

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