Battery current sampling safety diagnosis method and device

Abstract

The invention provides a battery current sampling safety diagnosis method and device, the method is applied to a battery management system, and the battery management system comprises a current sampling circuit and a processing module. The current sampling circuit comprises a voltage main sampling channel and a voltage auxiliary sampling channel of the shunt resistor, a first temperature signal sampling channel and a second temperature signal sampling channel, and is used for acquiring voltage sampling result values of the voltage main sampling channel and the voltage auxiliary sampling channel and carrying out first validity judgment; acquiring temperature signal sampling result values of the first temperature signal sampling channel and the second temperature signal sampling channel, performing second validity judgment, and outputting a shunt resistance voltage value and a shunt resistance temperature value; and determining the battery current value of the current diagnosis period and performing rationality judgment, and outputting the battery current value based on a rationality judgment result to perform battery algorithm application and / or battery fault judgment application, thereby improving the battery current sampling diagnosis coverage rate and the diagnosis safety level.

Description

Technical Field

[0001] The present application relates to the field of battery management, and in particular to a battery current sampling safety diagnosis method and device. Background Art

[0002] The battery management system (BMS) is a core component of electric vehicles. BMS needs to accurately monitor the status of the battery to ensure the performance and safety of the vehicle, especially to avoid the occurrence of battery thermal runaway due to battery overcurrent, so special attention is paid to the accuracy and safety of the current sampling function. At present, in order to achieve the requirements of low cost and high precision, current sampling is usually implemented based on shunt resistors, the voltage of the shunt resistor is obtained, and the current is calculated according to Ohm's law. However, the resistance of the shunt resistor changes due to the influence of temperature. In order to meet the accuracy requirements, a temperature sensor is usually arranged on the shunt resistor, and the resistance of the shunt resistor is calibrated according to the temperature. Therefore, BMS needs to collect the voltage at both ends of the shunt resistor and the voltage of the temperature sensor in real time, and then calculate the current value. In the prior art, BMS collects the voltage at both ends of the shunt resistor and the voltage of the temperature sensor, which is insufficient in hardware failure detection and fault identification, resulting in low coverage of the battery current safety mechanism and poor accuracy of data identification, resulting in the system may not be able to detect and respond to faults in time, thereby increasing the risk of dangerous situations in the vehicle. Summary of the invention

[0003] In view of this, the purpose of the present application is to provide a battery current sampling safety diagnosis method and device, which improves the battery current sampling diagnosis coverage and diagnosis safety level.

[0004] A battery current sampling safety diagnosis method provided in an embodiment of the present application is applied to a battery management system, wherein the battery management system includes a current sampling circuit and a processing module; the current sampling circuit includes a voltage main sampling channel and a voltage auxiliary sampling channel of a shunt resistor, and a first temperature signal sampling channel and a second temperature signal sampling channel respectively corresponding to two temperature sensors of the shunt resistor; the method includes:

[0005] Obtaining a first voltage sampling result value of a main voltage sampling channel and a second voltage sampling result value of a secondary voltage sampling channel of the shunt resistor within a diagnosis period, a first temperature signal sampling result value of a first temperature signal sampling channel, and a second temperature signal sampling result value of a second temperature signal sampling channel;

[0006] Perform a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and output the shunt resistor voltage value based on the first validity judgment result; perform a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and output the shunt resistor temperature value based on the second validity judgment result;

[0007] Determine the battery current value of this diagnostic cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature;

[0008] Perform rationality judgment on the battery current value of the current diagnosis cycle, determine the rationality judgment result, and output the battery current value of the current diagnosis cycle based on the rationality judgment result for battery algorithm application and / or battery fault judgment application.

[0009] In some embodiments, in the battery current sampling safety diagnosis method, before obtaining the first voltage sampling result value of the voltage main sampling channel and the second voltage sampling result value of the voltage auxiliary sampling channel of the shunt resistor within the diagnosis period, the first temperature signal sampling result value of the first temperature signal sampling channel and the second temperature signal sampling result value of the second temperature signal sampling channel, the method further includes:

[0010] The voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor are configured in a continuous synchronous sampling mode, and the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor are configured in a periodic trigger mode; the parameters of the continuous synchronous sampling mode include a sampling period, and the parameters of the periodic trigger mode include a diagnosis period; the diagnosis period is n sampling periods;

[0011] When the sampling period is reached, the voltage main sampling channel and the voltage auxiliary sampling channel are triggered to perform voltage sampling, and the voltage sampling results of n consecutive sampling periods within the diagnosis period are accumulated to obtain a first voltage sampling result value of the voltage main sampling channel and a second voltage sampling result value of the voltage auxiliary sampling channel;

[0012] When the diagnostic cycle is reached, the first voltage sampling result value of the voltage main sampling channel and the second voltage sampling result value of the voltage auxiliary sampling channel are read, and the first temperature signal sampling channel and the second temperature signal sampling channel are triggered to perform sampling at the same time, and the first temperature signal sampling result value of the first temperature signal sampling channel and the second temperature signal sampling result value of the second temperature signal sampling channel are read.

[0013] In some embodiments, in the battery current sampling safety diagnosis method, performing a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and outputting the shunt resistor voltage value based on the first validity judgment result; includes:

[0014] Determine whether the voltage main sampling channel and the voltage auxiliary sampling channel, the first voltage sampling result value and the second voltage sampling result value meet a plurality of preset resistance voltage validity conditions;

[0015] If all the conditions are met, the first validity judgment result is determined to be valid, and the first voltage sampling result value is output as the valid shunt resistor voltage value this time;

[0016] If any one of the conditions is not satisfied, the first validity judgment result is determined to be invalid, and the output shunt resistor voltage value remains the last valid shunt resistor voltage value;

[0017] The multiple preset resistance voltage validity conditions include: the first sampling power supply common to the voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor is normal, the absolute value of the difference between the first voltage sampling result value and the second voltage sampling result value is less than or equal to the first threshold, the first voltage sampling result value is greater than or equal to the second threshold and less than or equal to the third threshold at the same time, and the first voltage sampling result value is not completely the same as the first voltage sampling result values ​​of a preset number of times before the current diagnostic cycle.

[0018] In some embodiments, in the battery current sampling safety diagnosis method, performing a second validity judgment of the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and outputting the shunt resistor temperature value based on the second validity judgment result, includes:

[0019] Determine whether the first temperature signal sampling channel and the second temperature signal sampling channel, the first temperature signal sampling result value and the second temperature signal sampling result value meet a plurality of preset shunt resistor temperature validity conditions;

[0020] If all of them are satisfied, the second validity judgment result is determined to be valid, and the valid shunt resistor temperature value is output; the valid shunt resistor temperature value is obtained by converting the first temperature signal sampling result value;

[0021] If any one of the conditions is not satisfied, the second validity judgment result is determined to be invalid, and the output shunt resistor temperature value remains the last valid shunt resistor temperature value;

[0022] The multiple preset shunt resistor temperature validity conditions include: the second sampling power supply common to the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor is normal, the absolute value of the difference between the first temperature signal sampling result value and the second temperature signal sampling result value is less than or equal to the fourth threshold, the first temperature signal sampling result value is greater than or equal to the fifth threshold and at the same time less than or equal to the sixth threshold, and the first temperature signal sampling result value is not completely the same as the first temperature signal sampling result value of a preset number of times before this acquisition.

[0023] In some embodiments, in the battery current sampling safety diagnosis method, the battery current value of the current diagnosis cycle is determined according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature; including:

[0024] When the second validity judgment result is invalid and / or the first validity judgment result is invalid, the battery current value of this diagnostic cycle is invalid and the last valid battery current value is maintained;

[0025] When the second validity judgment result is valid and the first validity judgment result is valid, calibrating the resistance value of the shunt resistor according to a preset calibration formula to obtain the resistance value of the shunt resistor calibrated based on the temperature of the shunt resistor;

[0026] Based on the calibrated shunt resistor value and the shunt resistor voltage value, the battery current value of this diagnosis cycle is determined.

[0027] In some embodiments, in the battery current sampling safety diagnosis method, the rationality judgment of the battery current value of the current diagnosis cycle and the determination of the rationality judgment result include:

[0028] Determining whether the battery current value of the current diagnosis cycle meets multiple preset rationality conditions;

[0029] If all conditions are met, the current battery current value is determined to be valid, and the current valid battery current value is output;

[0030] If any of the conditions is not met, the current battery current value is determined to be invalid, and the output battery current value remains the last valid battery current value;

[0031] The multiple preset rationality conditions include: the battery current value this time is greater than or equal to the seventh threshold and less than or equal to the eighth threshold, the battery current change rate within the preset time period is less than the ninth threshold, the battery current change rate and the battery total voltage change rate within the preset time period are in opposite directions and the difference between the absolute value of the battery current change rate and the absolute value of the battery total voltage change rate is less than or equal to the tenth threshold.

[0032] In some embodiments, in the battery current sampling safety diagnosis method, the outputting of the battery current value based on the rationality judgment result for battery algorithm application and / or battery fault judgment application includes:

[0033] When the rationality judgment result is valid, outputting the battery current value for battery algorithm application;

[0034] When the rationality judgment result is invalid, a battery fault judgment is performed, and if the number of consecutive times that the rationality judgment result is invalid reaches a preset number threshold, a battery current fault is reported.

[0035] In some embodiments, the battery current sampling safety diagnosis method further includes:

[0036] A first power supply voltage value of a first sampling power supply and a second power supply voltage value of a second sampling power supply are synchronously measured by an additionally provided reference power supply and a reference analog-to-digital converter; the first sampling power supply is a common power supply for a voltage main sampling channel and a voltage auxiliary sampling channel of a shunt resistor; the second sampling power supply is a common power supply for a first temperature signal sampling channel and a second temperature signal sampling channel of a shunt resistor;

[0037] The first power supply voltage value is used to determine whether the first sampling power supply is faulty;

[0038] The second power supply voltage value is used to determine whether the second sampling power supply is faulty;

[0039] and / or,

[0040] The frequency error of the clock shared by the voltage main sampling channel and the voltage auxiliary sampling channel is supervised by an additionally provided low frequency oscillator.

[0041] In some embodiments, in the battery current sampling safety diagnosis method, the voltage main sampling channel of the shunt resistor includes a main analog-to-digital converter and a main serial communication interface; the voltage auxiliary sampling channel includes an auxiliary analog-to-digital converter and an auxiliary serial communication interface; the main analog-to-digital converter and the auxiliary analog-to-digital converter have the same architecture and opposite gain; the conversion results of the main analog-to-digital converter and the auxiliary analog-to-digital converter are the conversion results of the cumulative sum of n voltage sampling results;

[0042] and / or,

[0043] The first temperature signal sampling channel of the shunt resistor includes a first analog-to-digital converter and a first serial communication interface; the second temperature signal sampling channel includes a second analog-to-digital converter and a second serial communication interface; the first analog-to-digital converter and the second analog-to-digital converter have the same architecture and opposite gains; the conversion results of the first analog-to-digital converter and the second analog-to-digital converter are the conversion results of a single temperature signal.

[0044] In some embodiments, a battery current sampling safety diagnostic device is further provided, and the battery current sampling safety diagnostic device is applied to a battery management system, and the battery management system includes a current sampling circuit and a processing module; the current sampling circuit includes a voltage main sampling channel and a voltage auxiliary sampling channel of a shunt resistor, and a first temperature signal sampling channel and a second temperature signal sampling channel corresponding to two temperature sensors of the shunt resistor respectively; the device includes:

[0045] An acquisition module, used to acquire a first voltage sampling result value of a main voltage sampling channel and a second voltage sampling result value of a voltage auxiliary sampling channel of the shunt resistor within a diagnosis period, a first temperature signal sampling result value of a first temperature signal sampling channel and a second temperature signal sampling result value of a second temperature signal sampling channel;

[0046] A first judgment module is used to perform a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and output the shunt resistor voltage value based on the first validity judgment result; perform a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and output the shunt resistor temperature value based on the second validity judgment result;

[0047] a determination module, configured to determine a battery current value of this diagnosis cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature;

[0048] The second judgment module is used to make a rationality judgment on the battery current value of the current diagnosis cycle, determine the rationality judgment result, and output the battery current value of the current diagnosis cycle based on the rationality judgment result for battery algorithm application and / or battery fault judgment application.

[0049] An embodiment of the present application provides a battery current sampling safety diagnosis method and device, wherein the current sampling circuit includes a main voltage sampling channel and an auxiliary voltage sampling channel of a shunt resistor, and a first temperature signal sampling channel and a second temperature signal sampling channel of the shunt resistor, and obtains a first voltage sampling result value of the main voltage sampling channel of the shunt resistor and a second voltage sampling result value of the auxiliary voltage sampling channel, a first temperature signal sampling result value of the first temperature signal sampling channel, and a second temperature signal sampling result value of the second temperature signal sampling channel within a diagnosis period; performs a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and outputs the shunt resistor voltage value based on the first validity judgment result; performs a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value. , output the shunt resistor temperature value based on the second validity judgment result; determine the battery current value of this diagnostic cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature; make a rationality judgment on the battery current value of this diagnostic cycle, determine the rationality judgment result, and output the battery current value of this diagnostic cycle based on the rationality judgment result for battery algorithm application and / or battery fault judgment application; improve the diagnostic coverage rate through two independent voltage sampling channels and temperature signal sampling channels, and judge the validity of the current sampling value through multi-level validity judgment, ensure that the system maintains or enters a safe state when the current sampling fails, improve the safety and reliability of the vehicle, and prevent potential vehicle dangers caused by failure of the current sampling function. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 A method flow chart of the battery current sampling safety diagnosis method according to an embodiment of the present application is shown;

[0052] Figure 2 A flow chart of another battery current sampling safety diagnosis method according to an embodiment of the present application is shown;

[0053] Figure 3 A flow chart showing a first validity judgment of a shunt resistor voltage according to an embodiment of the present application is shown;

[0054] Figure 4A flow chart of a method for performing a second validity judgment on the temperature of a shunt resistor according to an embodiment of the present application is shown;

[0055] Figure 5 The battery current value for determining the current diagnosis cycle according to the embodiment of the present application is shown;

[0056] Figure 6 A battery current sampling safety diagnosis device described in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0057] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0058] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0059] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0060] The battery management system (BMS) is a core component of electric vehicles. BMS needs to accurately monitor the status of the battery to ensure the performance and safety of the vehicle, especially to avoid the occurrence of battery thermal runaway due to battery overcurrent, so special attention is paid to the accuracy and safety of the current sampling function. At present, in order to achieve the requirements of low cost and high precision, current sampling is usually implemented based on shunt resistors, the voltage of the shunt resistor is obtained, and the current is calculated according to Ohm's law. However, the resistance of the shunt resistor changes due to the influence of temperature. In order to meet the accuracy requirements, a temperature sensor is usually arranged on the shunt resistor, and the resistance of the shunt resistor is calibrated according to the temperature. Therefore, BMS needs to collect the voltage at both ends of the shunt resistor and the voltage of the temperature sensor in real time, and then calculate the current value. In the prior art, BMS collects the voltage at both ends of the shunt resistor and the voltage of the temperature sensor, which is insufficient in hardware failure detection and fault identification, resulting in low coverage of the battery current safety mechanism and poor accuracy of data identification, resulting in the system may not be able to detect and respond to faults in time, thereby increasing the risk of dangerous situations in the vehicle.

[0061] Based on this, an embodiment of the present application provides a battery current sampling safety diagnosis method and device, wherein the current sampling circuit includes a main voltage sampling channel and an auxiliary voltage sampling channel of the shunt resistor, and a first temperature signal sampling channel and a second temperature signal sampling channel of the shunt resistor, and obtains the first voltage sampling result value of the main voltage sampling channel of the shunt resistor and the second voltage sampling result value of the voltage auxiliary sampling channel, the first temperature signal sampling result value of the first temperature signal sampling channel and the second temperature signal sampling result value of the second temperature signal sampling channel within the diagnosis period; performs a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and outputs the shunt resistor voltage value based on the first validity judgment result; performs a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value. Judge, and output the shunt resistor temperature value based on the second validity judgment result; determine the battery current value of this diagnostic cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature; make a rationality judgment on the battery current value of this diagnostic cycle, determine the rationality judgment result, and output the battery current value of this diagnostic cycle based on the rationality judgment result for battery algorithm application and / or battery fault judgment application; improve the diagnostic coverage through two independent voltage sampling channels and temperature signal sampling channels, and judge the validity of the current sampling value through multi-level validity judgment, ensure that the system maintains or enters a safe state when the current sampling fails, improve the safety and reliability of the vehicle, and prevent potential vehicle dangers caused by failure of the current sampling function.

[0062] Embodiment 1

[0063] Please refer to Figure 1 , Figure 1 A method flow chart of a battery current sampling safety diagnosis method according to an embodiment of the present application is shown; the battery current sampling safety diagnosis method is applied to a battery management system, the battery management system includes a current sampling circuit and a processing module; the current sampling circuit includes a voltage main sampling channel and a voltage auxiliary sampling channel of a shunt resistor, and a first temperature signal sampling channel and a second temperature signal sampling channel of the shunt resistor; the method includes the following steps S101-S104;

[0064] S101, obtaining a first voltage sampling result value of a main voltage sampling channel and a second voltage sampling result value of a voltage auxiliary sampling channel of a shunt resistor within a diagnosis period, a first temperature signal sampling result value of a first temperature signal sampling channel and a second temperature signal sampling result value of a second temperature signal sampling channel;

[0065] S102, performing a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and outputting the shunt resistor voltage value based on the first validity judgment result; performing a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and outputting the shunt resistor temperature value based on the second validity judgment result;

[0066] S103, determining a battery current value of this diagnostic cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature;

[0067] S104, making a rationality judgment on the battery current value of the current diagnosis cycle, determining a rationality judgment result, and outputting the battery current value of the current diagnosis cycle based on the rationality judgment result for battery algorithm application and / or battery fault judgment application.

[0068] That is to say, in the embodiment of the present application, the voltage of the shunt resistor passes through two independent high-precision voltage sampling channels, the first one is the main voltage sampling channel of the shunt resistor, and the second one is the auxiliary voltage sampling channel of the shunt resistor.

[0069] Similarly, the temperature of the shunt resistor is acquired by two temperature sensors NTC1 and NTC2, and the voltage of NTC1 and the voltage of NTC2 are collected by two independent temperature signal sampling channels (specifically voltage sampling channels in the embodiment of the present application).

[0070] Based on this, the first temperature signal sampling channel and the second temperature signal sampling channel in the embodiment of the present application can be respectively referred to as the NTC1 voltage sampling channel and the NTC2 voltage sampling channel.

[0071] The following specifically describes the redundant sampling architecture of the voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor, and the temperature dual-channel redundant sampling architecture of the shunt resistor.

[0072] Specifically, in the battery current sampling safety diagnosis method described in the embodiment of the present application, the voltage main sampling channel of the shunt resistor includes a main analog-to-digital converter and a main serial communication interface; the voltage auxiliary sampling channel includes an auxiliary analog-to-digital converter and an auxiliary serial communication interface; the main analog-to-digital converter and the auxiliary analog-to-digital converter have the same architecture and opposite gains; the conversion results of the main analog-to-digital converter and the auxiliary analog-to-digital converter are the conversion results of the cumulative sum of n voltage sampling results;

[0073] and / or,

[0074] The first temperature signal sampling channel of the shunt resistor includes a first analog-to-digital converter and a first serial communication interface; the second temperature signal sampling channel includes a second analog-to-digital converter and a second serial communication interface; the first analog-to-digital converter and the second analog-to-digital converter have the same architecture and opposite gains; the conversion results of the first analog-to-digital converter and the second analog-to-digital converter are the conversion results of a single temperature signal.

[0075] Specifically, the main voltage sampling channel of the shunt resistor includes: a high-precision 18-bit analog-to-digital converter I1ADC (whose conversion result is I1ACCn), and a serial communication interface SP11; the auxiliary voltage sampling channel of the shunt resistor includes: a high-precision 18-bit analog-to-digital converter I2ADC (whose conversion result is I2ACCn), and a serial communication interface SP12. Among them, I1ADC and I2ADC have the same architecture and opposite gain, and I1ACCn and I2ACCn are n times cumulative sums. The main voltage sampling channel and auxiliary voltage sampling channel of the shunt resistor share the same first sampling power supply VREF1 and the same clock OSC1. In order to avoid common cause failure, an additional reference power supply VREF2 and a reference analog-to-digital converter REFADC are provided. The first sampling power supply VREF1 and the reference power supply VREF2 are synchronously measured by the analog-to-digital converter REFADC to realize fault monitoring of the first sampling power supply VREF1; an additional low-frequency oscillator OSC2 is provided to monitor the frequency error of the clock OSC1.

[0076] As described above, I1ACCn and I2ACCn are n-times accumulated sums, where n-times is determined based on the diagnosis cycle and the sampling cycles of the voltage main sampling channel and the voltage auxiliary sampling channel.

[0077] Here, the first sampling power supply VREF1 and the reference power supply VREF2 are synchronously measured by an independent reference analog-to-digital converter REFADC instead of using analog-to-digital converters I1ADC and I2ADC for acquisition. The reference power supply VREF2 independently supplies power to the reference analog-to-digital converter REFADC to avoid common cause failure.

[0078] The temperature NTC1 voltage sampling channel (first temperature signal sampling channel) of the shunt resistor includes: a high-precision 16-bit analog-to-digital converter V1ADC (conversion result VAn) and a serial communication interface SP11; the temperature NTC2 voltage sampling channel (second temperature signal sampling channel) of the shunt resistor includes: a high-precision 16-bit analog-to-digital converter V2ADC (conversion result VBn) and a serial communication interface SP12; wherein, V1ADC and V2ADC have the same architecture and opposite gain; the conversion results VAn and VBn are single conversion results. NTC1 and NTC2 share the same pull-up power supply VREF1P25. To avoid common cause failure, VREF1P25 is sampled and diagnosed through the reference analog-to-digital converter REFADC.

[0079] Embodiment 2

[0080] Please refer to Figure 2 , Figure 2 A flowchart of another battery current sampling safety diagnosis method described in an embodiment of the present application is shown; in the battery current sampling safety diagnosis method, before obtaining the first voltage sampling result value of the voltage main sampling channel and the second voltage sampling result value of the voltage auxiliary sampling channel of the shunt resistor within the diagnosis period, the first temperature signal sampling result value of the first temperature signal sampling channel and the second temperature signal sampling result value of the second temperature signal sampling channel, the method further includes the following steps S201-S203:

[0081] S201, configuring the voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor to be in a continuous synchronous sampling mode, and configuring the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor to be in a periodic trigger mode; the parameters of the continuous synchronous sampling mode include a sampling period, and the parameters of the periodic trigger mode include a diagnosis period; the diagnosis period is n sampling periods;

[0082] S202, when the sampling period is reached, triggering the voltage main sampling channel and the voltage auxiliary sampling channel to perform voltage sampling, and accumulating the voltage sampling results of n consecutive sampling periods within the diagnosis period to obtain a first voltage sampling result value of the voltage main sampling channel and a second voltage sampling result value of the voltage auxiliary sampling channel;

[0083] S203. When the diagnosis cycle is reached, read the first voltage sampling result value of the voltage main sampling channel and the second voltage sampling result value of the voltage auxiliary sampling channel, and simultaneously trigger the first temperature signal sampling channel and the second temperature signal sampling channel to perform sampling, and read the first temperature signal sampling result value of the first temperature signal sampling channel and the second temperature signal sampling result value of the second temperature signal sampling channel.

[0084] Specifically, in step S201, configuring the voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor to a continuous synchronous sampling mode includes: setting a sampling period t1, configuring for continuous sampling, the sampling result of the main sampling channel at time t1 is I1, the sampling result of the auxiliary sampling channel is I2, and the cumulative sums of I1 and I2 for n consecutive times are I1ACCn and I2ACCn.

[0085] The first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor are configured to be in periodic trigger mode, and this period is set to be the diagnostic period tn, where tn is n t1s. At this time, the sampling results of the main voltage sampling channel and the auxiliary voltage sampling channel are I1ACCn and I2ACCn. At the same time, the shunt resistor NTC1 voltage sampling channel and the NTC2 voltage sampling channel are triggered at time tn for sampling, and the sampling results are VT1n (the first temperature signal sampling result value) and VT2n (the second temperature signal sampling result value), thereby ensuring that I1ACCn (the first voltage sampling result value), I2ACCn (the second voltage sampling result value), VT1n (the first temperature signal sampling result value), and VT2n (the second temperature signal sampling result value) are the values ​​at the same time.

[0086] Exemplarily, the sampling period t1 is set to 1 ms, and the accumulated sums of I1 and I2 for n=8 consecutive times are I1ACCn and I2ACCn, and the corresponding diagnosis period is 8 ms.

[0087] In the step S103, a first validity judgment of the shunt resistor voltage is performed on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and the shunt resistor voltage value is output based on the first validity judgment result; a second validity judgment of the shunt resistor temperature is performed on the first temperature signal sampling result value and the second temperature signal sampling result value, and the shunt resistor temperature value is output based on the second validity judgment result.

[0088] Specifically, in the battery current sampling safety diagnosis method described in the embodiment of the present application, the first validity judgment of the shunt resistor voltage is performed on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and the shunt resistor voltage value is output based on the first validity judgment result; including:

[0089] Determine whether the voltage main sampling channel and the voltage auxiliary sampling channel, the first voltage sampling result value and the second voltage sampling result value meet a plurality of preset resistance voltage validity conditions;

[0090] If all the conditions are met, the first validity judgment result is determined to be valid, and the first voltage sampling result value is output as the valid shunt resistor voltage value this time;

[0091] If any one of the conditions is not satisfied, the first validity judgment result is determined to be invalid, and the output shunt resistor voltage value remains the last valid shunt resistor voltage value;

[0092] The multiple preset resistance voltage validity conditions include: the first sampling power supply common to the voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor is normal, the absolute value of the difference between the first voltage sampling result value and the second voltage sampling result value is less than or equal to the first threshold, the first voltage sampling result value is greater than or equal to the second threshold and less than or equal to the third threshold at the same time, and the first voltage sampling result value is not completely the same as the first voltage sampling result values ​​of a preset number of times before the current diagnostic cycle.

[0093] The preset number of first voltage sampling result values ​​before the current diagnosis cycle are the first voltage sampling result values ​​of the preset number of diagnosis cycles consecutive to the current diagnosis cycle, such as the previous diagnosis cycle, the previous diagnosis cycle, etc. Exemplarily, the preset number is 2 times.

[0094] Determine whether the voltage main sampling channel and the voltage auxiliary sampling channel, the first voltage sampling result value and the second voltage sampling result value meet multiple preset resistance voltage validity conditions. Specifically, determine in turn whether the voltage main sampling channel and the voltage auxiliary sampling channel, the first voltage sampling result value and the second voltage sampling result value meet multiple preset resistance voltage validity conditions. If not, determine that the first validity judgment result is invalid, and directly output the shunt resistor voltage value to maintain the last valid shunt resistor voltage value without the need to judge subsequent conditions.

[0095] For details, please refer to Figure 3 , Figure 3 FIG. 4 is a flowchart showing the first validity judgment of the shunt resistor voltage according to the embodiment of the present application; Figure 3 As shown, performing a first validity judgment on the shunt resistor voltage on the first voltage sampling result value I1ACCn and the second voltage sampling result value I2ACCn of the shunt resistor, and outputting the shunt resistor voltage value based on the first validity judgment result includes the following steps S301-S306:

[0096] S301: Read the values ​​of I1ACCn and I2ACCn;

[0097] S302: Determine whether the first sampling power supply VREF common to the two voltage sampling channels of the shunt resistor is faulty, and if there is no fault, execute S303; otherwise, the shunt resistor voltage VIn is invalid, and the output shunt resistor voltage value VIn maintains the last valid value;

[0098] S303: I1ACCn is subtracted from I2ACCn. If the absolute value of the difference is less than or equal to the first threshold, S304 is executed. Otherwise, the shunt resistor voltage VIn is invalid, and the output shunt resistor voltage value VIn maintains the last valid value. In other words, the deviation error of the sampling values ​​of the voltage main sampling channel and the voltage auxiliary sampling channel is determined. If the error is within a reasonable range, it means that the main sampling result I1ACCn is normal. If the error exceeds the reasonable range, it can be determined that the sampling of the main or auxiliary channel is abnormal. This reasonable range is determined according to the actual system (that is, the first threshold is determined according to the actual system).

[0099] S304: If I1ACCn≥the second threshold and I1ACCn≤the third threshold, and the third threshold is greater than the second threshold, execute S305, otherwise the shunt resistor voltage VIn is invalid, and the output shunt resistor voltage value VIn maintains the last valid value; that is, determine whether the main sampling channel result I1ACCn meets the sampling range, and this sampling range is determined according to the actual system (that is, the second threshold and the third threshold are determined according to the actual system);

[0100] S305: I1ACCn is compared with I1ACCn-1 and I1ACCn-2. If the three values ​​are not equal and there is no situation of no update for three consecutive times, then S306 is executed. Otherwise, the shunt resistor voltage VIn is invalid and the output shunt resistor voltage value VIn keeps the last valid value. Since the shunt resistor voltage sampling is high-precision sampling, there is no situation where the sampling values ​​are exactly the same for several consecutive times. If this happens, it is usually a hardware or software jam failure of the function execution. Therefore, it is necessary to compare the first voltage sampling result value with the preset number of first voltage sampling result values ​​before this acquisition to perform the first validity judgment.

[0101] S306: After the above steps, it is determined that the shunt resistor voltage VIn is valid, and the shunt resistor voltage value VIn=I1ACCn is output.

[0102] Specifically, in the battery current sampling safety diagnosis method described in the embodiment of the present application, performing a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and outputting the shunt resistor temperature value based on the second validity judgment result, includes:

[0103] Determine whether the first temperature signal sampling channel and the second temperature signal sampling channel, the first temperature signal sampling result value and the second temperature signal sampling result value meet a plurality of preset shunt resistor temperature validity conditions;

[0104] If all of them are satisfied, the second validity judgment result is determined to be valid, and the valid shunt resistor temperature value is output; the valid shunt resistor temperature value is obtained by converting the first temperature signal sampling result value;

[0105] If any one of the conditions is not satisfied, the second validity judgment result is determined to be invalid, and the output shunt resistor temperature value remains the last valid shunt resistor temperature value;

[0106] The multiple preset shunt resistor temperature validity conditions include: the second sampling power supply common to the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor is normal, the absolute value of the difference between the first temperature signal sampling result value and the second temperature signal sampling result value is less than or equal to the fourth threshold, the first temperature signal sampling result value is greater than or equal to the fifth threshold and at the same time less than or equal to the sixth threshold, and the first temperature signal sampling result value is not completely the same as the first temperature signal sampling result value of a preset number of times before this acquisition.

[0107] Determine whether the first temperature signal sampling channel and the second temperature signal sampling channel, the first temperature signal sampling result value and the second temperature signal sampling result value meet multiple preset shunt resistor temperature validity conditions. Specifically, determine in turn whether the first temperature signal sampling channel and the second temperature signal sampling channel, the first temperature signal sampling result value and the second temperature signal sampling result value meet multiple preset resistance voltage validity conditions. If not, determine that the second validity judgment result is invalid, and directly output the shunt resistor temperature value to maintain the last valid shunt resistor temperature value without the need to judge subsequent conditions.

[0108] For details, please refer to Figure 4 , Figure 4 The flowchart of the method for performing the second validity judgment of the shunt resistor temperature according to the embodiment of the present application is shown; the second validity judgment of the shunt resistor temperature is performed on the first temperature signal sampling result value VT1n and the second temperature signal sampling result value VT2n, and the shunt resistor temperature value is output based on the second validity judgment result, including the following steps S401-S406:

[0109] S401: Read VT1n and VT2n values;

[0110] S402: Determine whether the common reference power supply REF1P25 of the shunt resistor temperature NTC1 voltage sampling channel and the temperature NTC2 voltage sampling channel is faulty. If there is no fault, execute the third step. Otherwise, the shunt resistor temperature value Tn is invalid, and the output shunt resistor temperature value Tn maintains the last valid value.

[0111] S403: If the absolute value of the difference between VT1n and VT2n is less than or equal to the fourth threshold, execute S404, otherwise the shunt resistor temperature value Tn is invalid, and the output shunt resistor temperature value Tn maintains the last valid value; that is, determine the deviation error of the sampling value of the shunt resistor NTC1 sampling channel and the sampling value of the NTC2 sampling channel. If the error is within a reasonable range, it means that the NTC1 sampling value is normal. If the error exceeds the reasonable range, it can be determined that the NTC1 or NTC2 sampling is abnormal. This reasonable range is determined according to the actual system;

[0112] S404: If VT1n≥5th threshold and VT1n≤6th threshold, and the 6th threshold is greater than the 5th threshold, execute S405, otherwise the shunt resistor temperature value Tn is invalid, and the output shunt resistor temperature value Tn keeps the last valid value; that is, determine whether the NTC1 sampling channel result VT1n meets the sampling range, and this sampling range is determined according to the actual system;

[0113] S405: If VT1n is compared with VT1n-1 and VT1n-2, and the three values ​​are not equal, and there is no situation where there is no continuous non-update for three times, then S406 will be executed. Otherwise, the shunt resistor temperature value Tn is invalid, and the output shunt resistor temperature value Tn keeps the last valid value. This is because the shunt temperature NTC1 and NTC2 voltage sampling are high-precision sampling, and there is no situation where the sampling values ​​are exactly the same for several consecutive times. If this happens, it is usually a hardware or software jam failure of the function execution.

[0114] S406: Convert VT1n to shunt resistor temperature Tn, and the shunt resistor temperature Tn is valid.

[0115] In the above steps, it is judged that the first sampling power supply common to the voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor is normal, and it is judged that the second sampling power supply (reference power supply REF1P25) common to the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor is normal. Specifically, the first power supply voltage value of the first sampling power supply and the second power supply voltage value of the second sampling power supply are synchronously measured through an additionally provided reference power supply and a reference analog-to-digital converter; the first sampling power supply is a power supply common to the voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor; the second sampling power supply is a power supply common to the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor;

[0116] The first power supply voltage value is used to determine whether the first sampling power supply is faulty;

[0117] The second power supply voltage value is used to determine whether the second sampling power supply is faulty;

[0118] and / or,

[0119] The frequency error of the clock shared by the voltage main sampling channel and the voltage auxiliary sampling channel is supervised by an additionally provided low frequency oscillator.

[0120] The first power supply voltage value is used to determine whether the first sampled power supply is faulty; the second power supply voltage value is used to determine whether the second sampled power supply is faulty; specifically, the first power supply voltage value is compared with the first power supply preset value, and based on the comparison result, it is determined whether the first sampled power supply is faulty; the second power supply voltage value is compared with the second power supply preset value, and based on the comparison result, it is determined whether the second sampled power supply is faulty.

[0121] Since the first power supply voltage value of the first sampling power supply and the second power supply voltage value of the second sampling power supply are synchronously measured by the additionally provided reference power supply and the reference analog-to-digital converter, common cause failure is avoided, so the battery fault judgment of the first sampling power supply and the second sampling power supply is more accurate.

[0122] In the step S103, the battery current value of this diagnostic cycle is determined according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature.

[0123] Specifically, the battery current value of this diagnostic cycle is determined according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature; including:

[0124] When the second validity judgment result is invalid and / or the first validity judgment result is invalid, the battery current value of this diagnostic cycle is invalid and the last valid battery current value is maintained;

[0125] When the second validity judgment result is valid and the first validity judgment result is valid, calibrating the resistance value of the shunt resistor according to a preset calibration formula to obtain the resistance value of the shunt resistor calibrated based on the temperature of the shunt resistor;

[0126] Based on the calibrated shunt resistor value and the shunt resistor voltage value, the battery current value of this diagnosis cycle is determined.

[0127] After determining the battery current value of this diagnostic cycle, in step S104, the rationality of the battery current value of this diagnostic cycle is judged, the rationality judgment result is determined, and based on the rationality judgment result, the battery current value of this diagnostic cycle is output for battery algorithm application and / or battery fault judgment application.

[0128] Specifically, the rationality judgment of the battery current value of the current diagnosis cycle and determining the rationality judgment result include:

[0129] Determining whether the battery current value of the current diagnosis cycle meets multiple preset rationality conditions;

[0130] If all conditions are met, the current battery current value is determined to be valid, and the current valid battery current value is output;

[0131] If any of the conditions is not met, the current battery current value is determined to be invalid, and the output battery current value remains the last valid battery current value;

[0132] The multiple preset rationality conditions include: the battery current value this time is greater than or equal to the seventh threshold and less than or equal to the eighth threshold, the battery current change rate within the preset time period is less than the ninth threshold, the battery current change rate and the battery total voltage change rate within the preset time period are in opposite directions and the difference between the absolute value of the battery current change rate and the absolute value of the battery total voltage change rate is less than or equal to the tenth threshold.

[0133] Determine whether the battery current value of the current diagnostic cycle satisfies multiple preset rationality conditions; specifically, determine in turn whether the battery current value of the current diagnostic cycle satisfies multiple preset resistance voltage validity conditions. If not, determine that the current battery current value is invalid, and directly output the battery current value to maintain the last valid battery current value without the need to judge subsequent conditions.

[0134] Please refer to Figure 5 , Figure 5 A flow chart of a method for determining the battery current value of the current diagnostic cycle and judging the rationality of the battery current value of the current diagnostic cycle according to an embodiment of the present application is shown; specifically, the method for determining the battery current value In of the current diagnostic cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value Vn, and the shunt resistor resistance value Rn calibrated based on the shunt resistor temperature Tn, and judging the rationality of the battery current value In includes the following steps S501-S509:

[0135] S501: Obtain Tn value, Vn value, Tn validity flag, Vn validity flag;

[0136] S502: If Tn is valid, execute S503; otherwise, the battery current In is invalid and the current output value remains the last valid value;

[0137] S503: Calibrate the resistance of the shunt resistor according to a calibration formula, and obtain a calibrated resistance value of Rn;

[0138] S504: If Vn is valid, execute S505, otherwise the battery current In is invalid and the current value output value remains the last valid value;

[0139] S505: According to Ohm's law, calculate the battery current In=Vn / Rn;

[0140] S506: If In≥7th threshold and In≤8th threshold, and the 8th threshold is greater than the 7th threshold, execute S507, otherwise the battery current In is invalid and the current output value keeps the last valid value; that is, determine whether In meets the sampling range, and this sampling range is determined according to the actual system.

[0141] S507: If the current change rate is ≥ the ninth threshold, execute S508, otherwise execute S509; that is, judge the rationality of the current according to the current change trend. Usually, the change of battery current will cause the change of battery voltage. Within a certain current change range, the impact on voltage is small, and no judgment is made. Only when it is greater than a certain value, it will cause a more obvious voltage change, and judgment is made;

[0142] S508: If the current change rate is opposite to the voltage change rate and the difference between the current change rate and the voltage change rate is less than or equal to the tenth threshold, execute S509; otherwise, the battery current In is invalid and the current value output value remains the last valid value;

[0143] S509: Confirm that the battery current In is valid.

[0144] The outputting of the battery current value based on the rationality judgment result to perform battery algorithm application and / or battery fault judgment application includes:

[0145] When the rationality judgment result is valid, outputting the battery current value for battery algorithm application;

[0146] When the rationality judgment result is invalid, a battery fault judgment is performed, and if the number of consecutive times that the rationality judgment result is invalid reaches a preset number threshold, a battery current fault is reported.

[0147] That is to say, the battery current In is output for algorithm and battery fault judgment application, including: if In is valid, the system uses In to apply the battery algorithm; if In is invalid, a battery fault judgment is performed; if In is invalid for M consecutive times, a battery current fault is reported, and the entire vehicle remains in or enters a safe state.

[0148] In the battery current sampling safety diagnosis method described in the embodiment of the present application, the validity judgment of the shunt resistor voltage, the validity judgment of the shunt resistor temperature, and the rationality judgment of the battery current value in this diagnosis cycle are performed in sequence, and each judgment process includes multiple levels of judgment conditions, thereby providing a diagnostic safety level, reliably identifying current sampling faults, accurately identifying the validity of the battery current, and ensuring that the system maintains or enters a safe state when current sampling fails.

[0149] Embodiment 3

[0150] Based on the same inventive concept, a battery current sampling safety diagnosis device corresponding to the battery current sampling safety diagnosis method is also provided in the embodiment of the present application. Since the principle of solving the problem by the device in the embodiment of the present application is similar to the above-mentioned battery current sampling safety diagnosis method in the embodiment of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0151] Please refer to Figure 6 , Figure 6 A battery current sampling safety diagnostic device according to an embodiment of the present application is shown, and the device is applied to a battery management system, and the battery management system includes a current sampling circuit and a processing module; the current sampling circuit includes a voltage main sampling channel and a voltage auxiliary sampling channel of a shunt resistor, and a first temperature signal sampling channel and a second temperature signal sampling channel corresponding to two temperature sensors of the shunt resistor respectively; the device includes:

[0152] An acquisition module 601 is used to acquire a first voltage sampling result value of a voltage main sampling channel and a second voltage sampling result value of a voltage auxiliary sampling channel of a shunt resistor within a diagnosis period, a first temperature signal sampling result value of a first temperature signal sampling channel and a second temperature signal sampling result value of a second temperature signal sampling channel;

[0153] The first judgment module 602 is used to perform a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and output the shunt resistor voltage value based on the first validity judgment result; perform a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and output the shunt resistor temperature value based on the second validity judgment result;

[0154] A determination module 603, configured to determine a battery current value of this diagnosis cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature;

[0155] The second judgment module 604 is used to make a rationality judgment on the battery current value of the current diagnosis cycle, determine the rationality judgment result, and output the battery current value of the current diagnosis cycle based on the rationality judgment result for battery algorithm application and / or battery fault judgment application.

[0156] Embodiment 4

[0157] In some embodiments, the battery current sampling safety diagnostic device further includes:

[0158] A configuration module, used to configure the main voltage sampling channel and the auxiliary voltage sampling channel of the shunt resistor to a continuous synchronous sampling mode, and configure the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor to a periodic trigger mode before obtaining the first voltage sampling result value of the main voltage sampling channel and the second voltage sampling result value of the auxiliary voltage sampling channel, the first temperature signal sampling result value of the first temperature signal sampling channel and the second temperature signal sampling result value of the second temperature signal sampling channel within a diagnosis period; the parameters of the continuous synchronous sampling mode include a sampling period, and the parameters of the periodic trigger mode include a diagnosis period; the diagnosis period is n sampling periods;

[0159] When the sampling period is reached, the voltage main sampling channel and the voltage auxiliary sampling channel are triggered to perform voltage sampling, and the voltage sampling results of n consecutive sampling periods within the diagnosis period are accumulated to obtain a first voltage sampling result value of the voltage main sampling channel and a second voltage sampling result value of the voltage auxiliary sampling channel;

[0160] When the diagnostic cycle is reached, the first voltage sampling result value of the voltage main sampling channel and the second voltage sampling result value of the voltage auxiliary sampling channel are read, and the first temperature signal sampling channel and the second temperature signal sampling channel are triggered to perform sampling at the same time, and the first temperature signal sampling result value of the first temperature signal sampling channel and the second temperature signal sampling result value of the second temperature signal sampling channel are read.

[0161] In some embodiments, the first judgment module in the battery current sampling safety diagnostic device performs a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and outputs the shunt resistor voltage value based on the first validity judgment result, specifically for:

[0162] Determine whether the voltage main sampling channel and the voltage auxiliary sampling channel, the first voltage sampling result value and the second voltage sampling result value meet a plurality of preset resistance voltage validity conditions;

[0163] If all the conditions are met, the first validity judgment result is determined to be valid, and the first voltage sampling result value is output as the valid shunt resistor voltage value this time;

[0164] If any one of the conditions is not satisfied, the first validity judgment result is determined to be invalid, and the output shunt resistor voltage value remains the last valid shunt resistor voltage value;

[0165] The multiple preset resistance voltage validity conditions include: the first sampling power supply common to the voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor is normal, the absolute value of the difference between the first voltage sampling result value and the second voltage sampling result value is less than or equal to the first threshold, the first voltage sampling result value is greater than or equal to the second threshold and less than or equal to the third threshold at the same time, and the first voltage sampling result value is not completely the same as the first voltage sampling result values ​​of a preset number of times before the current diagnostic cycle.

[0166] In some embodiments, the first judgment module in the battery current sampling safety diagnosis device performs a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and outputs the shunt resistor temperature value based on the second validity judgment result, specifically for:

[0167] Determine whether the first temperature signal sampling channel and the second temperature signal sampling channel, the first temperature signal sampling result value and the second temperature signal sampling result value meet a plurality of preset shunt resistor temperature validity conditions;

[0168] If all of them are satisfied, the second validity judgment result is determined to be valid, and the valid shunt resistor temperature value is output; the valid shunt resistor temperature value is obtained by converting the first temperature signal sampling result value;

[0169] If any one of the conditions is not satisfied, the second validity judgment result is determined to be invalid, and the output shunt resistor temperature value remains the last valid shunt resistor temperature value;

[0170] The multiple preset shunt resistor temperature validity conditions include: the second sampling power supply common to the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor is normal, the absolute value of the difference between the first temperature signal sampling result value and the second temperature signal sampling result value is less than or equal to the fourth threshold, the first temperature signal sampling result value is greater than or equal to the fifth threshold and at the same time less than or equal to the sixth threshold, and the first temperature signal sampling result value is not completely the same as the first temperature signal sampling result value of a preset number of times before this acquisition.

[0171] In some embodiments, the determination module in the battery current sampling safety diagnosis device, when determining the battery current value of the current diagnosis cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature, is specifically used to:

[0172] When the second validity judgment result is invalid and / or the first validity judgment result is invalid, the battery current value of this diagnostic cycle is invalid and the last valid battery current value is maintained;

[0173] When the second validity judgment result is valid and the first validity judgment result is valid, calibrating the resistance value of the shunt resistor according to a preset calibration formula to obtain the resistance value of the shunt resistor calibrated based on the temperature of the shunt resistor;

[0174] Based on the calibrated shunt resistor value and the shunt resistor voltage value, the battery current value of this diagnosis cycle is determined.

[0175] In some embodiments, the second judgment module in the battery current sampling safety diagnosis device is specifically used to:

[0176] Determining whether the battery current value of the current diagnosis cycle meets multiple preset rationality conditions;

[0177] If all conditions are met, the current battery current value is determined to be valid, and the current valid battery current value is output;

[0178] If any of the conditions is not met, the current battery current value is determined to be invalid, and the output battery current value remains the last valid battery current value;

[0179] The multiple preset rationality conditions include: the battery current value this time is greater than or equal to the seventh threshold and less than or equal to the eighth threshold, the battery current change rate within the preset time period is less than the ninth threshold, the battery current change rate and the battery total voltage change rate within the preset time period are in opposite directions and the difference between the absolute value of the battery current change rate and the absolute value of the battery total voltage change rate is less than or equal to the tenth threshold.

[0180] In some embodiments, the second judgment module in the battery current sampling safety diagnosis device is specifically used to:

[0181] When the rationality judgment result is valid, outputting the battery current value for battery algorithm application;

[0182] When the rationality judgment result is invalid, a battery fault judgment is performed, and if the number of consecutive times that the rationality judgment result is invalid reaches a preset number threshold, a battery current fault is reported.

[0183] In some embodiments, the battery current sampling safety diagnostic device further includes:

[0184] A synchronous measurement module, used for synchronously measuring a first power supply voltage value of a first sampling power supply and a second power supply voltage value of a second sampling power supply through an additionally provided reference power supply and a reference analog-to-digital converter; the first sampling power supply is a common power supply for a voltage main sampling channel and a voltage auxiliary sampling channel of a shunt resistor; the second sampling power supply is a common power supply for a first temperature signal sampling channel and a second temperature signal sampling channel of a shunt resistor;

[0185] The first power supply voltage value is used to determine whether the first sampling power supply is faulty;

[0186] The second power supply voltage value is used to determine whether the second sampling power supply is faulty;

[0187] and / or,

[0188] The frequency error of the clock shared by the voltage main sampling channel and the voltage auxiliary sampling channel is supervised by an additionally provided low frequency oscillator.

[0189] In some embodiments, in the battery current sampling safety diagnostic device, the voltage main sampling channel of the shunt resistor includes a main analog-to-digital converter and a main serial communication interface; the voltage auxiliary sampling channel includes an auxiliary analog-to-digital converter and an auxiliary serial communication interface; the main analog-to-digital converter and the auxiliary analog-to-digital converter have the same architecture and opposite gain; the conversion results of the main analog-to-digital converter and the auxiliary analog-to-digital converter are the conversion results of the cumulative sum of n voltage sampling results;

[0190] and / or,

[0191] The first temperature signal sampling channel of the shunt resistor includes a first analog-to-digital converter and a first serial communication interface; the second temperature signal sampling channel includes a second analog-to-digital converter and a second serial communication interface; the first analog-to-digital converter and the second analog-to-digital converter have the same architecture and opposite gains; the conversion results of the first analog-to-digital converter and the second analog-to-digital converter are the conversion results of a single temperature signal.

[0192] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the method embodiment, and will not be repeated in this application. In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0193] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0194] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0195] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a platform server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks, or optical disks.

[0196] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery current sampling safety diagnosis method, characterized in that: Applied to a battery management system, the battery management system includes a current sampling circuit and a processing module; the current sampling circuit includes a voltage main sampling channel and a voltage auxiliary sampling channel of a shunt resistor, and a first temperature signal sampling channel and a second temperature signal sampling channel respectively corresponding to two temperature sensors of the shunt resistor; the method includes: Obtaining a first voltage sampling result value of a main voltage sampling channel and a second voltage sampling result value of a secondary voltage sampling channel of the shunt resistor within a diagnosis period, a first temperature signal sampling result value of a first temperature signal sampling channel, and a second temperature signal sampling result value of a second temperature signal sampling channel; Perform a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and output the shunt resistor voltage value based on the first validity judgment result; perform a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and output the shunt resistor temperature value based on the second validity judgment result; Determine the battery current value of this diagnostic cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature; Perform rationality judgment on the battery current value of the current diagnosis cycle, determine the rationality judgment result, and output the battery current value of the current diagnosis cycle based on the rationality judgment result for battery algorithm application and / or battery fault judgment application.

2. The battery current sampling safety diagnosis method according to claim 1, characterized in that: Before obtaining the first voltage sampling result value of the voltage main sampling channel and the second voltage sampling result value of the voltage auxiliary sampling channel of the shunt resistor within the diagnosis period, the first temperature signal sampling result value of the first temperature signal sampling channel and the second temperature signal sampling result value of the second temperature signal sampling channel, the method further includes: The voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor are configured in a continuous synchronous sampling mode, and the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor are configured in a periodic trigger mode; the parameters of the continuous synchronous sampling mode include a sampling period, and the parameters of the periodic trigger mode include a diagnosis period; the diagnosis period is n sampling periods; When the sampling period is reached, the voltage main sampling channel and the voltage auxiliary sampling channel are triggered to perform voltage sampling, and the voltage sampling results of n consecutive sampling periods within the diagnosis period are accumulated to obtain a first voltage sampling result value of the voltage main sampling channel and a second voltage sampling result value of the voltage auxiliary sampling channel; When the diagnostic cycle is reached, the first voltage sampling result value of the voltage main sampling channel and the second voltage sampling result value of the voltage auxiliary sampling channel are read, and the first temperature signal sampling channel and the second temperature signal sampling channel are triggered to perform sampling at the same time, and the first temperature signal sampling result value of the first temperature signal sampling channel and the second temperature signal sampling result value of the second temperature signal sampling channel are read.

3. The battery current sampling safety diagnosis method according to claim 1, characterized in that: The first voltage sampling result value and the second voltage sampling result value of the shunt resistor are used to perform a first validity judgment on the shunt resistor voltage, and output the shunt resistor voltage value based on the first validity judgment result; comprising: Determine whether the voltage main sampling channel and the voltage auxiliary sampling channel, the first voltage sampling result value and the second voltage sampling result value meet a plurality of preset resistance voltage validity conditions; If all the conditions are met, the first validity judgment result is determined to be valid, and the first voltage sampling result value is output as the valid shunt resistor voltage value this time; If any one of the conditions is not satisfied, the first validity judgment result is determined to be invalid, and the output shunt resistor voltage value remains the last valid shunt resistor voltage value; The multiple preset resistance voltage validity conditions include: the first sampling power supply common to the voltage main sampling channel and the voltage auxiliary sampling channel of the shunt resistor is normal, the absolute value of the difference between the first voltage sampling result value and the second voltage sampling result value is less than or equal to the first threshold, the first voltage sampling result value is greater than or equal to the second threshold and less than or equal to the third threshold at the same time, and the first voltage sampling result value is not completely the same as the first voltage sampling result values ​​of a preset number of times before the current diagnostic cycle.

4. The battery current sampling safety diagnosis method according to claim 1, characterized in that: The step of performing a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and outputting the shunt resistor temperature value based on the second validity judgment result, comprises: Determine whether the first temperature signal sampling channel and the second temperature signal sampling channel, the first temperature signal sampling result value and the second temperature signal sampling result value meet a plurality of preset shunt resistor temperature validity conditions; If all of them are satisfied, the second validity judgment result is determined to be valid, and the valid shunt resistor temperature value is output; the valid shunt resistor temperature value is obtained by converting the first temperature signal sampling result value; If any one of the conditions is not satisfied, the second validity judgment result is determined to be invalid, and the output shunt resistor temperature value remains the last valid shunt resistor temperature value; The multiple preset shunt resistor temperature validity conditions include: the second sampling power supply common to the first temperature signal sampling channel and the second temperature signal sampling channel of the shunt resistor is normal, the absolute value of the difference between the first temperature signal sampling result value and the second temperature signal sampling result value is less than or equal to the fourth threshold, the first temperature signal sampling result value is greater than or equal to the fifth threshold and at the same time less than or equal to the sixth threshold, and the first temperature signal sampling result value is not completely the same as the first temperature signal sampling result value of a preset number of times before this acquisition.

5. The battery current sampling safety diagnosis method according to claim 1, characterized in that: Determining the battery current value of this diagnostic cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature; including: When the second validity judgment result is invalid and / or the first validity judgment result is invalid, the battery current value of this diagnostic cycle is invalid and the last valid battery current value is maintained; When the second validity judgment result is valid and the first validity judgment result is valid, calibrating the resistance value of the shunt resistor according to a preset calibration formula to obtain the resistance value of the shunt resistor calibrated based on the temperature of the shunt resistor; Based on the calibrated shunt resistor value and the shunt resistor voltage value, the battery current value of this diagnosis cycle is determined.

6. The battery current sampling safety diagnosis method according to claim 5, characterized in that: The rationality of the battery current value of the current diagnosis cycle is judged to determine the rationality judgment result, including: Determining whether the battery current value of the current diagnosis cycle meets multiple preset rationality conditions; If all conditions are met, the current battery current value is determined to be valid, and the current valid battery current value is output; If any of the conditions is not met, the current battery current value is determined to be invalid, and the output battery current value remains the last valid battery current value; The multiple preset rationality conditions include: the battery current value this time is greater than or equal to the seventh threshold and less than or equal to the eighth threshold, within the preset time period - the battery current change rate is less than the ninth threshold, within the preset time period - the battery current change rate and the battery total voltage change rate are in opposite directions and the difference between the absolute value of the battery current change rate and the absolute value of the battery total voltage change rate is less than or equal to the tenth threshold.

7. The battery current sampling safety diagnosis method according to claim 1 or 5, characterized in that: The outputting of the battery current value based on the rationality judgment result to perform battery algorithm application and / or battery fault judgment application includes: When the rationality judgment result is valid, outputting the battery current value for battery algorithm application; When the rationality judgment result is invalid, a battery fault judgment is performed, and if the number of consecutive times that the rationality judgment result is invalid reaches a preset number threshold, a battery current fault is reported.

8. The battery current sampling safety diagnosis method according to claim 1, characterized in that: The method further comprises: A first power supply voltage value of a first sampling power supply and a second power supply voltage value of a second sampling power supply are synchronously measured by an additionally provided reference power supply and a reference analog-to-digital converter; the first sampling power supply is a common power supply for a voltage main sampling channel and a voltage auxiliary sampling channel of a shunt resistor; the second sampling power supply is a common power supply for a first temperature signal sampling channel and a second temperature signal sampling channel of a shunt resistor; The first power supply voltage value is used to determine whether the first sampling power supply is faulty; The second power supply voltage value is used to determine whether the second sampling power supply is faulty; and / or, The frequency error of the clock shared by the voltage main sampling channel and the voltage auxiliary sampling channel is supervised by an additionally provided low frequency oscillator.

9. The battery current sampling safety diagnosis method according to claim 2, characterized in that: The voltage main sampling channel of the shunt resistor includes a main analog-to-digital converter and a main serial communication interface; the voltage auxiliary sampling channel includes an auxiliary analog-to-digital converter and an auxiliary serial communication interface; the main analog-to-digital converter and the auxiliary analog-to-digital converter have the same architecture and opposite gains; the conversion results of the main analog-to-digital converter and the auxiliary digital-to-analog-to-digital converter are the conversion results of the cumulative sum of n voltage sampling results; and / or, The first temperature signal sampling channel of the shunt resistor includes a first analog-to-digital converter and a first serial communication interface; the second temperature signal sampling channel includes a second analog-to-digital converter and a second serial communication interface; the first analog-to-digital converter and the second analog-to-digital converter have the same architecture and opposite gains; the conversion results of the first analog-to-digital converter and the second analog-to-digital converter are the conversion results of a single temperature signal.

10. A battery current sampling safety diagnostic device, characterized in that: Applied to a battery management system, the battery management system includes a current sampling circuit and a processing module; the current sampling circuit includes a voltage main sampling channel and a voltage auxiliary sampling channel of a shunt resistor, and a first temperature signal sampling channel and a second temperature signal sampling channel corresponding to two temperature sensors of the shunt resistor respectively; the device includes: An acquisition module, used to acquire a first voltage sampling result value of a main voltage sampling channel and a second voltage sampling result value of a voltage auxiliary sampling channel of the shunt resistor within a diagnosis period, a first temperature signal sampling result value of a first temperature signal sampling channel and a second temperature signal sampling result value of a second temperature signal sampling channel; A first judgment module is used to perform a first validity judgment on the shunt resistor voltage on the first voltage sampling result value and the second voltage sampling result value of the shunt resistor, and output the shunt resistor voltage value based on the first validity judgment result; perform a second validity judgment on the shunt resistor temperature on the first temperature signal sampling result value and the second temperature signal sampling result value, and output the shunt resistor temperature value based on the second validity judgment result; a determination module, configured to determine a battery current value of this diagnosis cycle according to the first validity judgment result, the second validity judgment result, the shunt resistor voltage value, and the shunt resistor resistance value calibrated based on the shunt resistor temperature; The second judgment module is used to make a rationality judgment on the battery current value of the current diagnosis cycle, determine the rationality judgment result, and output the battery current value of the current diagnosis cycle based on the rationality judgment result for battery algorithm application and / or battery fault judgment application.

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