Current sensor detection method and device based on multi-branch battery pack

Abstract

The embodiment of the invention discloses a current sensor detection method and device based on a multi-branch battery pack, belongs to the technical field of electric vehicles, and solves the problem that the whole vehicle performance of the electric vehicle is reduced due to inaccurate current collection of the multi-branch battery pack. Comprising the steps of obtaining battery management data corresponding to a previous driving cycle, and determining a sensor diagnosis mode parameter based on the battery management data; starting a sensor diagnosis mode under the condition that the sensor diagnosis mode parameter meets a preset current sensor diagnosis mode starting condition; controlling the on and off of a plurality of diagnosis relays, a battery pack relay and a main negative relay, so that the total discharge current of the multi-branch battery pack sequentially passes through a plurality of current sensors; and comparing the multi-branch current detection data obtained by the plurality of current sensors with a preset current sensor fault parameter threshold, and determining the fault conditions of the plurality of current sensors and the total current value of the battery pack based on the comparison result.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a current sensor detection method and device based on a multi-branch battery pack. Background Art

[0002] In recent years, due to the increasing prominence of climate change, environmental pollution and energy crisis, efficient and zero-emission electric vehicles have been developed on a large scale. Power batteries have become the preferred solution for new energy vehicles. However, issues such as safety, cost and cycle performance have always restricted the market competitiveness of power electric vehicles, especially for the heavy truck industry. In order to ensure the driving range, it is necessary to adopt multi-branch battery packs, that is, multiple battery packs are connected in parallel to increase the battery capacity of the vehicle and increase the driving range. Among them, the current detection of the battery pack is particularly critical. The impact of the battery pack current on the performance and stability of the power battery has always been valued by people.

[0003] The current mainstream battery data collection method is the Hall sensor designed based on the Hall effect. However, with the use of the vehicle, the Hall sensor will inevitably produce temperature drift, zero drift, overload, magnetic flux saturation and other problems, which makes it difficult for the BMS (Battery Management System) to obtain accurate battery pack current values. This will make it difficult for the BMS to accurately estimate the remaining battery power, prevent overcharging, over-discharging and balance management. It is difficult to achieve the original function. For multi-branch battery packs, there are current sensors on each branch, and the above problems are more prominent. Inaccurate current collection will directly lead to poor consistency of each battery pack, thereby reducing the overall performance of the electric vehicle. Summary of the invention

[0004] The embodiments of the present application provide a current sensor detection method and device based on a multi-branch battery pack, which are used to solve the following technical problems: for a multi-branch battery pack, inaccurate current collection will directly lead to poor consistency of each battery pack, thereby reducing the overall vehicle performance of the electric vehicle.

[0005] The present application embodiment adopts the following technical solutions:

[0006] The embodiment of the present application provides a current sensor detection method based on a multi-branch battery pack. The method includes: obtaining battery management data corresponding to the last driving cycle, determining sensor diagnostic mode parameters based on the battery management data; turning on the sensor diagnostic mode when the sensor diagnostic mode parameters meet the preset current sensor diagnostic mode start-up conditions; controlling the opening and closing of multiple diagnostic relays, battery pack relays, and main negative relays so that the total discharge current of the multi-branch battery pack passes through multiple current sensors in sequence; comparing the multi-branch current detection data obtained by multiple current sensors with the preset current sensor fault parameter threshold, and determining the fault conditions of multiple current sensors and the total current value of the battery pack based on the comparison results.

[0007] The embodiment of the present application adjusts the diagnostic mode parameters according to the specific battery status and historical data, so that the diagnostic process is more in line with the actual situation and the diagnostic efficiency is improved. Secondly, multiple current sensors are used to monitor the current of multiple branches to achieve comprehensive coverage of the total discharge current of the battery pack and reduce monitoring blind spots. In the sensor diagnostic mode, the embodiment of the present application disables the conventional main negative relay and battery pack relay, drives multiple diagnostic relays to complete the control of the high-voltage discharge negative pole circuit, and combines the device to realize that the total discharge current of the battery pack can pass through multiple current sensors in sequence, thereby diagnosing multiple current sensors. This diagnostic method is convenient and reliable. This ensures that the current acquisition is more accurate and improves the overall performance of electric vehicles.

[0008] In one implementation of the present application, battery management data corresponding to a previous driving cycle is obtained, and sensor diagnostic mode parameters are determined based on the battery management data, specifically including: obtaining battery management data corresponding to the previous driving cycle; wherein the battery management data corresponding to the previous driving cycle includes at least one of temperature values ​​corresponding to a plurality of battery packs, current values ​​corresponding to a plurality of battery packs, aging values ​​corresponding to a plurality of battery packs, battery fault status, vehicle status, and a flag variable status value of a sensor diagnostic mode; when it is determined that the temperature values ​​corresponding to the plurality of battery packs are respectively within an operating temperature threshold range, the battery fault status is no current fault, the vehicle status is a lower high voltage state, and the flag variable status value of the sensor diagnostic mode is an on state value, the sensor diagnostic mode parameters are determined based on the current values ​​corresponding to the plurality of battery packs and the aging values ​​corresponding to the plurality of battery packs.

[0009] In one implementation of the present application, based on the current values ​​corresponding to multiple battery packs and the aging values ​​corresponding to the multiple battery packs, the sensor diagnostic mode parameters are determined, specifically including: obtaining the current value collected by the current sensor within a first preset detection time period; wherein the first preset detection time period includes multiple first time segments; performing average processing on the current values ​​corresponding to the multiple first time segments to obtain a first average current value of the current sensor within the first preset detection time period; performing difference processing on the first average current values ​​corresponding to the multiple current sensors within the first preset detection time period to obtain an absolute value of the first current difference; performing difference processing on the aging values ​​of different detection time periods corresponding to the battery pack to obtain the absolute value of the aging difference; using the absolute value of the first current difference and the absolute value of the aging difference as the sensor diagnostic mode parameters.

[0010] In one implementation of the present application, when the sensor diagnostic mode parameters meet the preset current sensor diagnostic mode start-up conditions, the sensor diagnostic mode is turned on, specifically including: when the absolute value of the first current difference is greater than the preset current value threshold, and the absolute value of the aging difference is less than the preset aging difference threshold, the sensor diagnostic mode is turned on.

[0011] In one implementation of the present application, the opening and closing of multiple diagnostic relays, battery pack relays and main negative relays are controlled so that the total discharge current of the multi-branch battery pack passes through multiple current sensors in sequence, specifically including: determining that the flag variable state value of the sensor diagnostic mode is on; controlling the battery pack relay and the main negative relay to remain disconnected; and driving multiple diagnostic relays to close so that the total discharge current of the multi-branch battery pack passes through multiple current sensors in sequence; wherein, multiple diagnostic relays, battery pack relays and main negative relays are all arranged between the battery pack and the battery high-voltage distribution box.

[0012] In one implementation of the present application, multi-branch current detection data acquired by multiple current sensors are compared with a preset current sensor fault parameter threshold, specifically including: acquiring multi-branch current detection data collected by the current sensor within a second preset detection time period; wherein the second preset detection time period includes multiple second time segments; performing mean processing on the multi-branch current detection data corresponding to the multiple second time segments, to obtain a second average current value of the current sensor within the second preset detection time period; performing difference processing on the second average current values ​​corresponding to the multiple current sensors within the second preset detection time period, to obtain an absolute value of the second current difference, so as to compare the absolute value of the second current difference with the preset current sensor fault parameter threshold.

[0013] In one implementation of the present application, the fault conditions of multiple current sensors and the total current value of the battery pack are determined based on the comparison results, specifically including: when the absolute value of the second current difference is not greater than the preset current sensor fault parameter threshold, determining that the current sensor is in a non-fault state; performing average processing on the second average current values ​​corresponding to the multiple current sensors to obtain a third average current value; and using the third average current value as the total current value of the battery pack corresponding to the current sensor in a non-fault state.

[0014] In one implementation of the present application, the fault conditions of multiple current sensors and the total current value of the battery pack are determined based on the comparison results, specifically including: when the absolute value of the second current difference is greater than a preset current sensor fault parameter threshold, determining that the current sensor is in a fault state; determining the minimum value among the second average current values ​​corresponding to the multiple current sensors, and using the minimum value as the total current value of the battery pack corresponding to the current sensor fault state.

[0015] In one implementation of the present application, after determining the fault conditions of multiple current sensors and the total current value of the battery pack based on the comparison results, the method also includes: adjusting the flag variable state value of the sensor diagnostic mode to an off state to exit the sensor diagnostic mode; controlling multiple diagnostic relays to disconnect; and driving the battery pack relay and the main negative relay to close so that the total discharge current of the multi-branch battery pack passes through at least one current sensor.

[0016] An embodiment of the present application provides a current sensor detection device based on a multi-branch battery pack, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can: obtain battery management data corresponding to the previous driving cycle, and determine sensor diagnostic mode parameters based on the battery management data; turn on the sensor diagnostic mode when the sensor diagnostic mode parameters meet the preset current sensor diagnostic mode start conditions; control the opening and closing of multiple diagnostic relays, battery pack relays and main negative relays so that the total discharge current of the multi-branch battery pack passes through multiple current sensors in sequence; compare the multi-branch current detection data obtained by the multiple current sensors with the preset current sensor fault parameter threshold, and determine the fault conditions of the multiple current sensors and the total current value of the battery pack based on the comparison results.

[0017] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects: The embodiments of the present application adjust the diagnostic mode parameters according to the specific battery status and historical data, so that the diagnostic process is more in line with the actual situation and the diagnostic efficiency is improved. Secondly, multiple branch currents are monitored by multiple current sensors to achieve comprehensive coverage of the total discharge current of the battery pack and reduce monitoring blind spots. In the sensor diagnostic mode, the embodiments of the present application disable the conventional main negative relay and battery pack relay, drive multiple diagnostic relays to complete the control of the high-voltage discharge negative pole circuit, and combine the device to realize that the total discharge current of the battery pack can pass through multiple current sensors in sequence, thereby diagnosing multiple current sensors. This diagnostic method is convenient and reliable. This ensures that the current acquisition is more accurate and improves the overall vehicle performance of electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. In the drawings:

[0019] Figure 1 A flow chart of a current sensor detection method based on a multi-branch battery pack provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the structure of a multi-branch current sensor fault detection device provided in an embodiment of the present application;

[0021] Figure 3 A flow chart of a current sensor detection process based on a multi-branch battery pack provided in an embodiment of the present application;

[0022] Figure 4 A schematic structural diagram of a current sensor detection device based on a multi-branch battery pack provided in an embodiment of the present application.

[0023] Reference numerals:

[0024] 200: Current sensor detection device based on multi-branch battery pack, 201: Processor, 202: Memory. DETAILED DESCRIPTION

[0025] The embodiments of the present application provide a current sensor detection method, device and medium based on a multi-branch battery pack.

[0026] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0027] The technical solution proposed in the embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0028] Figure 1 A flow chart of a current sensor detection method based on a multi-branch battery pack provided in an embodiment of the present application is as follows: Figure 1 As shown, the current sensor detection method based on a multi-branch battery pack includes the following steps:

[0029] Step 101: Obtain battery management data corresponding to the last driving cycle, and determine sensor diagnosis mode parameters based on the battery management data.

[0030] In one embodiment of the present application, the necessary structural basis of the embodiment of the present application is to enable two current Hall sensors to sequentially measure the magnitude of the total current for fault diagnosis. Figure 2 A schematic diagram of a multi-branch current sensor fault detection device provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the multi-branch current sensor fault detection device adds two diagnostic relays ChkRly1 and ChkRly2 to the original traditional structure; Figure 2 Battery pack 1 and battery pack 2 are connected in parallel to increase the capacity, and the battery high-voltage distribution box is responsible for the distribution of the total battery power. PackRly is a battery pack relay, which is used to disconnect the connection between the two packs to avoid circulating current; PosRly is the main positive relay of the positive circuit, which is used to control the high-voltage discharge positive circuit; NegRly is the main negative relay of the negative circuit, which is used to control the high-voltage discharge negative circuit; A1 and A2 are the Hall current sensors on the negative side of the discharge circuit of battery pack 1 and battery pack 2, respectively, current sensor 1 and current sensor 2.

[0031] The embodiment of the present application collects some internal variables of the BMS of the previous driving cycle and determines whether the preset conditions are met to determine whether the sensor diagnostic mode is turned on or off. In the sensor diagnostic mode, the conventional main negative relay and battery pack relay are disabled, and the two diagnostic relays are driven to complete the control of the high-voltage discharge negative pole circuit. The combined device enables the total discharge current of the battery pack to pass through the two current sensors in sequence, thereby diagnosing the two current sensors.

[0032] In one embodiment of the present application, the battery management data corresponding to the last driving cycle is obtained; wherein the battery management data corresponding to the last driving cycle includes at least one of the temperature values ​​corresponding to the multiple battery packs, the current values ​​corresponding to the multiple battery packs, the aging values ​​corresponding to the multiple battery packs, the battery fault status, the vehicle status, and the flag variable status value of the sensor diagnosis mode. When it is determined that the temperature values ​​corresponding to the multiple battery packs are respectively within the operating temperature threshold range, the battery fault status is no current fault, the vehicle status is a lower high voltage state, and the flag variable status value of the sensor diagnosis mode is an on state value, the sensor diagnosis mode parameters are determined based on the current values ​​corresponding to the multiple battery packs and the aging values ​​corresponding to the multiple battery packs.

[0033] Specifically, in new energy vehicles, the battery management system will continuously collect and record various parameters and status information of the battery. When the vehicle completes a driving cycle (such as from starting to shutting down), these data will be saved for subsequent analysis and diagnosis. The battery management data corresponding to the previous driving cycle obtained in the embodiment of the present application includes the average temperature of multiple battery packs, the real current value collected by multiple current sensors, the aging degree of multiple battery packs, whether various types of faults detected during the operation of the BMS controller occur, and the flag variable of the sensor diagnostic mode, where 0 is off and 1 is on. The status of the vehicle: the status of the vehicle: generally high voltage online, low high voltage, charging, etc.

[0034] Furthermore, after obtaining the battery management data, the obtained data is analyzed, including: the temperature value of the battery pack must be within the operating temperature threshold range to ensure that the battery is in normal working condition and will not affect the diagnosis result due to overheating or overcooling; the battery fault state must be no current fault, that is, no fault directly related to the current is detected to avoid unnecessary diagnosis under the fault state; the vehicle state should be the lower high voltage state; the flag variable state value of the sensor diagnostic mode must be the open state value, indicating that the system is ready to enter the sensor diagnostic mode. Further, after the above conditions are met, the parameters of the sensor diagnostic mode are set according to the current value and aging value of the battery pack.

[0035] In one embodiment of the present application, a current value collected by a current sensor within a first preset detection time period is obtained; wherein the first preset detection time period includes multiple first time segments. The current values ​​corresponding to the multiple first time segments are averaged to obtain a first average current value of the current sensor within the first preset detection time period. The first average current values ​​corresponding to the multiple current sensors within the first preset detection time period are differenced to obtain an absolute value of the first current difference. The aging values ​​of the battery pack corresponding to different detection time periods are differenced to obtain an absolute value of the aging difference. The absolute value of the first current difference and the absolute value of the aging difference are used as sensor diagnostic mode parameters.

[0036] Specifically, the embodiment of the present application pre-sets a first preset detection time period, and continuously collects current values ​​from the current sensor. This time period can be set to a few minutes, a few hours or according to specific needs, and the embodiment of the present application does not limit this. Secondly, the first preset detection time period is divided into multiple shorter time periods, i.e., multiple first time segments, and then the current values ​​of the multiple first time segments in the first preset detection time period are averaged to obtain the first average current value. The above steps are performed for each sensor respectively to obtain the respective first average current values. For example, a 5-minute detection time period is divided into 30 10-second time periods (i.e., the first time segment), and the current values ​​in the 30 time periods are averaged to obtain the average current values ​​corresponding to the 30 time periods, which are used as the first average current value corresponding to the 5-minute detection time.

[0037] Further, the difference between these first average current values ​​is calculated, for example, by comparing them two by two or uniformly comparing them to a reference value, and taking the absolute value to measure the consistency of the readings between the sensors. For example, there are two current sensors in the system, and the first average current values ​​obtained are A and B respectively, and |AB| is calculated as the absolute value of the first current difference.

[0038] Furthermore, the battery pack will gradually age during use, which will affect its performance, including current output. In order to more accurately evaluate the performance of the current sensor, the embodiment of the present application takes the aging factor of the battery pack into account. The embodiment of the present application compares the aging values ​​of the battery pack at different detection periods and calculates the difference. The absolute value of the first current difference is combined with the absolute value of the aging difference as the sensor diagnostic mode parameter.

[0039] Step 102: When the sensor diagnosis mode parameters meet the preset current sensor diagnosis mode start-up conditions, start the sensor diagnosis mode.

[0040] In one embodiment of the present application, when the absolute value of the first current difference is greater than a preset current value threshold and the absolute value of the aging difference is less than a preset aging difference threshold, the sensor diagnosis mode is turned on.

[0041] Specifically, if the absolute value of the first current difference, that is, the difference between the average current values ​​measured by different sensors in the same time period, is greater than the preset current value threshold, then the readings of these sensors are within the unacceptable range. The absolute value of the aging difference, that is, the difference between the aging values ​​of the battery pack in different detection periods, is not greater than the preset aging difference threshold. When the above two conditions are met at the same time, the sensor diagnostic mode is turned on.

[0042] Step 103 , controlling the opening and closing of multiple diagnostic relays, battery pack relays, and a main negative relay, so that the total discharge current of the multi-branch battery pack passes through multiple current sensors in sequence.

[0043] In one embodiment of the present application, the state value of the flag variable of the sensor diagnostic mode is determined to be in the on state. The battery pack relay and the main negative relay are controlled to remain disconnected. And, multiple diagnostic relays are driven to close so that the total discharge current of the multi-branch battery pack passes through multiple current sensors in sequence. Among them, multiple diagnostic relays, battery pack relays and main negative relays are all arranged between the battery pack and the battery high-voltage distribution box.

[0044] Specifically, the embodiment of the present application is provided with a flag to indicate that the sensor diagnostic mode has been entered, where 0 is off and 1 is on. When the flag is set to the on state, the sensor diagnostic function will be turned on. In the sensor diagnostic mode, for safety reasons, it is necessary to ensure that the connection between the battery pack and the main circuit is cut off. The embodiment of the present application achieves this by controlling the state of the battery pack relay and the main negative relay. The battery pack relay is located between the battery pack and the battery high-voltage distribution box, and is used to control the power output of the battery pack. The main negative relay is located at the output end of the battery high-voltage distribution box, and is used to control the on and off of high voltage electricity. Keeping them in the disconnected state can prevent accidental current flow during the diagnosis process and protect the safety of the system.

[0045] Furthermore, in the sensor diagnostic mode, multiple diagnostic relays are driven to close. These diagnostic relays are also set between the battery pack and the battery high-voltage distribution box to switch the current path during the diagnostic process. When they are closed, one or more current loops can be formed so that the total discharge current of the battery pack can pass through multiple current sensors in sequence. By comparing the readings of these sensors, their accuracy and consistency can be evaluated.

[0046] Step 104 : comparing the multi-branch current detection data acquired by the multiple current sensors with the preset current sensor fault parameter threshold, and determining the fault conditions of the multiple current sensors and the total current value of the battery pack based on the comparison result.

[0047] In one embodiment of the present application, the multi-branch current detection data collected by the current sensor in a second preset detection time period is obtained; wherein the second preset detection time period includes a plurality of second time segments. The multi-branch current detection data corresponding to the plurality of second time segments are averaged to obtain a second average current value of the current sensor in the second preset detection time period. The second average current values ​​corresponding to the plurality of current sensors in the second preset detection time period are differenced to obtain an absolute value of the second current difference, so as to compare the absolute value of the second current difference with a preset current sensor fault parameter threshold.

[0048] Specifically, the embodiment of the present application pre-sets a second preset detection time period, and the second preset detection time period is divided into multiple second time periods. In the second preset detection time period, the current detection data of multiple branches corresponding to the multiple second time segments are averaged to obtain the second average current value of the second preset detection time period. The difference between these second average current values ​​is calculated, for example, it can be compared two by two or uniformly compared to a reference value, and the absolute value is taken to measure the consistency of the readings between the sensors. The absolute value of the second current difference is compared with the preset current sensor fault parameter threshold.

[0049] In one embodiment of the present application, when the absolute value of the second current difference is not greater than the preset current sensor fault parameter threshold, it is determined that the current sensor is in a fault-free state. The second average current values ​​corresponding to the multiple current sensors are averaged again to obtain a third average current value. The third average current value is used as the total current value of the battery pack corresponding to the fault-free state of the current sensor.

[0050] Specifically, when the absolute value of the second current difference is not greater than the preset current sensor fault parameter threshold, the sensor is determined to be fault-free. At this time, the second average current values ​​corresponding to all current sensors are averaged again to obtain a more comprehensive current value, namely the third average current value, which is regarded as the value of the total current of the battery pack in a fault-free state. For example, assuming that there are three current sensors A, B, and C, and the second average current values ​​measured in the second preset detection time period are 100A, 102A, and 99A respectively, the third average current value is calculated: (100A+102A+99A) / 3=100.33A, which is used as the total current value of the battery pack corresponding to the fault-free state of the current sensor.

[0051] In one embodiment of the present application, when the absolute value of the second current difference is greater than a preset current sensor fault parameter threshold, it is determined that the current sensor is in a fault state. The minimum value of the second average current values ​​corresponding to the multiple current sensors is determined, and the minimum value is used as the total current value of the battery pack corresponding to the current sensor fault state.

[0052] Specifically, when the absolute value of the second current difference is greater than a preset current sensor fault parameter threshold, it is determined that the current sensor is in a fault state. At this time, the minimum value is selected from the second average current values ​​of multiple current sensors as the value of the total current of the battery pack.

[0053] In one embodiment of the present application, the flag variable state value of the sensor diagnostic mode is adjusted to the off state to exit the sensor diagnostic mode. A plurality of diagnostic relays are controlled to be disconnected. And, the battery pack relay and the main negative relay are driven to close so that the total discharge current of the multi-branch battery pack passes through at least one current sensor.

[0054] Specifically, after the diagnosis process is completed, the state value of the flag variable is adjusted from the open state to the closed state to indicate that the sensor diagnosis mode has been exited. At the same time, the diagnostic relay is controlled to be disconnected to restore the normal connection of the circuit, and the battery pack relay and the main negative relay are controlled to be in a closed state to allow the total discharge current of the multi-branch battery pack to be normally monitored by at least one current sensor.

[0055] Figure 3 A flow chart of a current sensor detection process based on a multi-branch battery pack provided in an embodiment of the present application is as follows: Figure 3 As shown, in the current sensor detection process based on the multi-branch battery pack, the data of the previous driving cycle is first obtained, including: IO_Pack1Temp, IO_Pack2Temp, IO_iact1, IO_iact2, SOC_Pack1SOH, SOC_Pack2SOH, battery fault status, diagnostic enable and vehicle status. Among them, driving cycle: from the power on to the power off of the BMS controller is defined as a driving cycle; IO_Pack1Temp, IO_Pack2Temp: the average temperature of battery pack 1 and battery pack 2 respectively; IO_iact1, IO_iact2: the real current value collected by current sensor 1 and current sensor 2 respectively; SOC_Pack1SOH, SOC_Pack2SOH: the aging degree of battery pack 1 and battery pack 2 respectively; battery fault status: whether various faults detected during the operation of the BMS controller occur; diagnostic enable: the flag bit variable of the sensor diagnostic mode, where 0 is off and 1 is on; vehicle status: the status of the vehicle: generally high voltage online, low voltage, charging, etc.

[0056] Further, it is determined that the temperature values ​​corresponding to the multiple battery packs are respectively within the operating temperature threshold range, the battery fault state is determined to be no current fault, the vehicle state is determined to be a lower high voltage state, and the diagnostic enable is determined to be 0, that is, the flag variable state value of the sensor diagnostic mode is a closed state value. It should be noted that the operating temperature threshold range is set to 20°C-35°C in the embodiment of the present application, which can be adjusted in actual applications, and the embodiment of the present application does not limit this.

[0057] Furthermore, the current values ​​corresponding to the acquired battery packs are subtracted and their absolute values ​​are obtained, and the aging values ​​corresponding to the acquired battery packs are subtracted and their absolute values ​​are obtained.

[0058] Furthermore, the obtained absolute values ​​are compared with the set thresholds respectively. If the threshold requirements are met, the sensor diagnosis mode is entered. Otherwise, multiple diagnostic relays are controlled to be disconnected, and the battery pack relay and the main negative relay are driven to be closed.

[0059] After entering the sensor diagnosis mode, determine that the diagnosis enable is 1, control the battery pack relay and the main negative relay to be disconnected, and control multiple diagnostic relays to be closed so that the total discharge current of the multi-branch battery pack passes through multiple current sensors in sequence.

[0060] Furthermore, in the sensor diagnosis mode, the current values ​​corresponding to each battery pack are recorded, and the obtained current values ​​are subtracted and the absolute value is taken. The obtained absolute value is compared with the preset threshold value. If it is greater than the preset threshold value, an unreliable fault of the battery pack branch sensor is reported, and the total current of the battery pack takes the minimum current value among multiple battery packs. If it is not greater than the preset threshold value, the battery pack branch sensor is not faulty. At this time, the total current of the battery pack takes the average value of the currents of multiple battery packs, and the sensor diagnosis mode is exited, the diagnosis enable is set to 0, the driving of the diagnostic relay is prohibited in the upper high voltage instruction, and the driving control battery pack relay and the main negative relay are closed.

[0061] Figure 4 The present invention provides a schematic diagram of a current sensor detection device based on a multi-branch battery pack. Figure 4As shown, a current sensor detection device 200 based on a multi-branch battery pack includes: at least one processor 201; and a memory 202 that is communicatively connected to the at least one processor 201; wherein the memory 202 stores instructions that can be executed by the at least one processor 201, and the instructions are executed by the at least one processor 201 so that the at least one processor 201 can: obtain battery management data corresponding to the previous driving cycle, and determine sensor diagnostic mode parameters based on the battery management data; turn on the sensor diagnostic mode when the sensor diagnostic mode parameters meet the preset current sensor diagnostic mode start conditions; control the opening and closing of multiple diagnostic relays, battery pack relays and main negative relays so that the total discharge current of the multi-branch battery pack passes through multiple current sensors in sequence; compare the multi-branch current detection data obtained by the multiple current sensors with the preset current sensor fault parameter threshold, and determine the fault conditions of the multiple current sensors and the total current value of the battery pack based on the comparison results.

[0062] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, equipment, and non-volatile computer storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0063] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the embodiments of the present application may have various changes and variations. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A current sensor detection method based on a multi-branch battery pack, characterized in that: The method comprises: Acquiring battery management data corresponding to a previous driving cycle, and determining a sensor diagnostic mode parameter based on the battery management data; When the sensor diagnosis mode parameter meets the preset current sensor diagnosis mode start condition, start the sensor diagnosis mode; Control the opening and closing of multiple diagnostic relays, battery pack relays and main negative relays so that the total discharge current of the multi-branch battery pack passes through multiple current sensors in sequence; The multi-branch current detection data acquired by the multiple current sensors are compared with the preset current sensor fault parameter threshold, and the fault conditions of the multiple current sensors and the total current value of the battery pack are determined based on the comparison results.

2. A current sensor detection method based on a multi-branch battery pack according to claim 1, characterized in that: The acquiring of battery management data corresponding to the last driving cycle and determining the sensor diagnosis mode parameters based on the battery management data specifically includes: Acquiring battery management data corresponding to the last driving cycle; wherein the battery management data corresponding to the last driving cycle includes at least one of the temperature values ​​corresponding to the plurality of battery packs, the current values ​​corresponding to the plurality of battery packs, the aging values ​​corresponding to the plurality of battery packs, the battery fault status, the vehicle status, and the flag variable status value of the sensor diagnosis mode; When it is determined that the temperature values ​​corresponding to the multiple battery packs are respectively within the operating temperature threshold range, the battery fault state is no current fault, the vehicle state is a lower high voltage state, and the flag variable state value of the sensor diagnostic mode is an on state value, the sensor diagnostic mode parameters are determined based on the current values ​​corresponding to the multiple battery packs and the aging values ​​corresponding to the multiple battery packs.

3. A current sensor detection method based on a multi-branch battery pack according to claim 2, characterized in that: The determining of the sensor diagnosis mode parameter based on the current values ​​respectively corresponding to the plurality of battery packs and the aging values ​​respectively corresponding to the plurality of battery packs specifically includes: Acquire the current value collected by the current sensor within a first preset detection time period; wherein the first preset detection time period includes a plurality of first time segments; Performing average processing on the current values ​​corresponding to the plurality of the first time segments respectively, to obtain a first average current value of the current sensor in the first preset detection time period; Performing difference processing on the first average current values ​​respectively corresponding to the plurality of current sensors within the first preset detection time period to obtain an absolute value of a first current difference; Performing difference processing on the aging values ​​of the battery pack at different detection periods to obtain an absolute value of the aging difference; The absolute value of the first current difference and the absolute value of the aging difference are used as the sensor diagnosis mode parameters.

4. A current sensor detection method based on a multi-branch battery pack according to claim 3, characterized in that: When the sensor diagnosis mode parameter meets the preset current sensor diagnosis mode start condition, starting the sensor diagnosis mode specifically includes: When the absolute value of the first current difference is greater than a preset current value threshold, and the absolute value of the aging difference is less than a preset aging difference threshold, the sensor diagnosis mode is started.

5. A current sensor detection method based on a multi-branch battery pack according to claim 1, characterized in that: The controlling of the opening and closing of the plurality of diagnostic relays, the battery pack relay and the main negative relay so that the total discharge current of the multi-branch battery pack passes through the plurality of current sensors in sequence specifically includes: Determine that the state value of the flag variable of the sensor diagnostic mode is an on state; Controlling the battery pack relay and the main negative relay to remain disconnected; And, driving the plurality of the diagnostic relays to close so that the total discharge current of the multi-branch battery pack passes through the plurality of current sensors in sequence; Among them, the plurality of diagnostic relays, the battery pack relays and the main negative relay are all arranged between the battery pack and the battery high-voltage distribution box.

6. A current sensor detection method based on a multi-branch battery pack according to claim 1, characterized in that: The comparing the multi-branch current detection data acquired by the multiple current sensors with the preset current sensor fault parameter threshold specifically includes: Acquire multi-branch current detection data collected by the current sensor within a second preset detection time period; wherein the second preset detection time period includes a plurality of second time segments; Performing average processing on the multi-branch current detection data corresponding to the plurality of second time segments respectively, to obtain a second average current value of the current sensor in the second preset detection time period; The second average current values ​​respectively corresponding to the multiple current sensors in the second preset detection time period are subjected to difference processing to obtain an absolute value of a second current difference, so as to compare the absolute value of the second current difference with the preset current sensor fault parameter threshold.

7. A current sensor detection method based on a multi-branch battery pack according to claim 6, characterized in that: Determining the fault conditions of the multiple current sensors and the total current value of the battery pack based on the comparison results specifically includes: When the absolute value of the second current difference is not greater than the preset current sensor fault parameter threshold, determining that the current sensor is in a non-fault state; Performing average processing again on the second average current values ​​corresponding to the multiple current sensors to obtain a third average current value; The third average current value is used as the total current value of the battery pack corresponding to when the current sensor is in a fault-free state.

8. A current sensor detection method based on a multi-branch battery pack according to claim 6, characterized in that: Determining the fault conditions of the multiple current sensors and the total current value of the battery pack based on the comparison results specifically includes: When the absolute value of the second current difference is greater than the preset current sensor fault parameter threshold, determining that the current sensor is in a fault state; A minimum value among the second average current values ​​corresponding to the multiple current sensors is determined, and the minimum value is used as the total current value of the battery pack corresponding to the current sensor failure state.

9. A current sensor detection method based on a multi-branch battery pack according to claim 1, characterized in that: After determining the fault conditions of the plurality of current sensors and the total current value of the battery pack based on the comparison result, the method further includes: Adjusting the state value of the flag variable of the sensor diagnostic mode to an off state to exit the sensor diagnostic mode; Controlling a plurality of the diagnostic relays to be disconnected; And, driving the battery pack relay and the main negative relay to close so that the total discharge current of the multi-branch battery pack passes through at least one of the current sensors.

10. A current sensor detection device based on a multi-branch battery pack, characterized in that: The device comprises a memory for storing computer program instructions and a processor for executing the program instructions, wherein when the computer program instructions are executed by the processor, the device is triggered to execute the method according to any one of claims 1 to 9.

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