A method for detecting battery management system failure using an off-board charger

Abstract

A method for an off-board charger to detect battery management system failure includes the following steps: S1, the off-board charger obtains the initial electrical parameters of the vehicle's battery management system; S2, during vehicle charging, the off-board charger periodically obtains the real-time electrical parameters of the vehicle's battery management system; S3, during vehicle charging, the off-board charger periodically obtains its own charging electromechanical parameters, which correspond to the real-time electrical parameters; S4, comparing the charging electromechanical parameters with the real-time electrical parameters and the initial electrical parameters. If the real-time electrical parameters are not greater than the charging electromechanical parameters and the charging electromechanical parameters are not greater than the initial electrical parameters, charging proceeds normally and the process returns to S2; otherwise, the battery management system is determined to have failed. In the present invention, the off-board charger determines whether the battery management system has failed based on the real-time electrical parameters, thus enabling the off-board charger to actively detect battery management system failure.

Description

Technical Field

[0001] The present invention relates to the technical field of charger detection of battery management systems, in particular to a method for an off-vehicle charger to detect failure of a battery management system. Background Art

[0002] With the increase in electric vehicles, off-board chargers have also been widely used. During the charging process of electric vehicles, the failure of the electric vehicle battery management system is very dangerous. At present, the detection of electric vehicle battery management systems mainly relies on the fault information actively reported by the electric vehicle battery management system. However, off-board chargers cannot judge the battery management system based on the charging data reported by the battery management system. Summary of the Invention

[0003] In order to solve the problem in the prior art that non-on-board chargers are unable to determine the status of the battery management system based on the charging data of the battery management system, the present invention provides a method for an off-board charger to detect failure of the battery management system. During the charging process, the off-board charger periodically obtains the real-time electrical parameters of the battery management system and determines whether the battery management system has failed based on the real-time electrical parameters, thereby enabling the off-board charger to actively detect failure of the battery management system.

[0004] To achieve the above objectives, the present invention adopts a specific solution: a method for detecting battery management system failure by an off-board charger, comprising the following steps:

[0005] S1, the off-board charger obtains the initial electrical parameters of the vehicle battery management system;

[0006] S2, during vehicle charging, the off-board charger periodically obtains real-time electrical parameters from the vehicle battery management system;

[0007] S3, during the vehicle charging process, the off-board charger periodically obtains the charging electromechanical parameters of the off-board charger, and the charging electromechanical parameters correspond to the real-time electrical parameters;

[0008] S4, compare the charging electromechanical parameters with the real-time electrical parameters and the initial electrical parameters. If the real-time electrical parameters are not greater than the charging electromechanical parameters and the charging electromechanical parameters are not greater than the initial electrical parameters, charging is performed normally and returns to S2. Otherwise, it is determined that the battery management system has failed.

[0009] This is a further optimization of the method for detecting battery management system failure by an off-board charger of the present invention: S1 is specifically,

[0010] S11, the off-board charger obtains initial data of the vehicle battery management system;

[0011] S12, obtaining initial electrical parameters according to the initial data.

[0012] Further optimization of the method for detecting failure of a battery management system by a non-vehicle charger of the present invention: the initial data includes the rated battery capacity Q 额 , Rated battery voltage U 额 , Maximum allowable charging voltage U max , vehicle battery state of charge SOC 整车 and the current battery state of charge SOC 当前 .

[0013] Further optimization of the method for detecting battery management system failure by a non-vehicle charger of the present invention: the initial electrical parameter is the maximum chargeable capacity per 1% SOC

[0014] This is a further optimization of the method for detecting battery management system failure by an off-board charger of the present invention: S12 is specifically as follows:

[0015] S121, according to Q 额 and U 额 Get the total power W required by the battery 总 ,

[0016] W 总 =Q 额 ×U 额 / 1000

[0017] Among them, Q 额 The unit is Ah, U 额 The unit is V, W 总 The unit is KW·h;

[0018] S122, obtain the theoretical charge required for each 1% SOC based on the total battery charge required

[0019]

[0020] S123, obtaining initial electrical parameters based on the theoretical charge required for each 1% SOC

[0021]

[0022] Among them, a=3~5.

[0023] This is a further optimization of the method for detecting battery management system failure by an off-board charger of the present invention: the real-time electrical parameters include charging voltage measurement values ​​and charging current measurement values.

[0024] This is a further optimization of the method for detecting battery management system failure by an off-board charger of the present invention: the charger's electrical parameters include the charger's output voltage value, the charger's output current value, and the cycle charging capacity.

[0025] This is a further optimization of the method for detecting battery management system failure by a non-on-board charger of the present invention: S4 specifically compares the periodic charging power with the initial electrical parameters, the charging voltage measurement value with the charger output voltage value, and the charging current measurement value with the charger output current value. If the periodic charging power is not greater than the initial electrical parameters, the charging voltage measurement value is not greater than the charger output voltage value, and the charging current measurement value is not greater than the charger output current value, then normal charging is performed and the process returns to S2; otherwise, the battery management system is determined to have failed.

[0026] Beneficial Effects: The present invention provides a method for an off-board charger to detect battery management system failure. During charging, the off-board charger first obtains the battery management system's initial electrical parameters. It then periodically obtains the battery management system's real-time electrical parameters and, at the same time, periodically obtains the charger's electrical parameters. Finally, the charger parameters are compared with the real-time and initial electrical parameters to determine whether the battery management system has failed. This means that the off-board charger monitors the battery management system's status in real time, enabling timely resolution if the battery management system fails. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] A method for detecting battery management system failure by an off-board charger comprises the following steps:

[0030] S1, the off-board charger obtains the initial electrical parameters of the vehicle battery management system. In this embodiment, the off-board charger includes a controller, a power detection device, an output voltage and current detection device, and a battery management system interaction control device.

[0031] S1 is specifically:

[0032] S11, the off-board charger obtains the initial data of the vehicle battery management system through the battery management system interactive control device in the off-board charger. The initial data is the rated battery capacity Q 额 , Rated battery voltage U 额 , Maximum allowable charging voltage U max, vehicle battery state of charge SOC 整车 and the current battery state of charge SOC 当前 .

[0033] S12, obtaining initial electrical parameters based on the initial data, the initial electrical parameters being the maximum chargeable capacity per 1% SOC

[0034] S12 is specifically:

[0035] S121, according to Q 额 and U 额 Get the total power W required by the battery 总 ,

[0036] W 总 =Q 额 ×U 额 / 1000

[0037] Among them, Q 额 The unit is Ah, U 额 The unit is V, W 总 The unit is KW·h;

[0038] S122, obtain the theoretical charge required for each 1% SOC based on the total battery charge required

[0039]

[0040] S123, obtaining initial electrical parameters based on the theoretical charge required for each 1% SOC During the charging process, the actual charge required for each 1% SOC of the battery is different at different stages, so the theoretical charge required for each 1% SOC needs to be corrected:

[0041]

[0042] Wherein, a is the correction coefficient, a=3~5.

[0043] S2: During vehicle charging, the off-board charger periodically obtains real-time electrical parameters from the vehicle battery management system, and obtains real-time electrical parameters according to the battery management system interactive control device. The real-time electrical parameters include the required voltage, required current, the current SOC of the battery, the charging voltage measurement value, and the charging current measurement value. In this embodiment, one change in the current SOC value of the battery is one cycle.

[0044] During vehicle charging, the off-board charger periodically acquires its own electromechanical parameters, including the charger's output voltage, output current, and cycle charge capacity. In this embodiment, the output voltage and current detection device acquires the charger's output voltage and output current. The charge capacity at the start and end of the cycle is read using the charge capacity detection device. The cycle charge capacity is the difference between the end charge capacity and the start charge capacity. These electromechanical parameters correspond to the real-time electrical parameters.

[0045] S4, compare the charging electromechanical parameters with the real-time electrical parameters and the initial electrical parameters. If the real-time electrical parameters are not greater than the charging electromechanical parameters and the charging electromechanical parameters are not greater than the initial electrical parameters, charging is performed normally and returns to S2. Otherwise, it is determined that the battery management system has failed.

[0046] S4 is specifically as follows: Figure 1 As shown, the periodic charging capacity is compared with the initial electrical parameters, the charging voltage measurement value is compared with the charger output voltage value, and the charging current measurement value is compared with the charger output current value. If the periodic charging capacity is not greater than the initial electrical parameters, the charging voltage measurement value is not greater than the charger output voltage value, and the charging current measurement value is not greater than the charger output current value, then charging is normal and returns to S2. Otherwise, it is determined that the battery management system has failed.

[0047] It should be noted that in S4, the comparison between the periodic charging power and the initial electrical parameters, the comparison between the charging voltage measurement value and the charger output voltage value, and the comparison between the charging voltage measurement value and the charger output current value can be compared in any order or at the same time.

[0048] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting battery management system failure by an off-board charger, characterized in that: The following steps are involved: S1, the off-board charger obtains the initial electrical parameters of the vehicle battery management system; the initial electrical parameters are the maximum chargeable capacity per 1% SOC S2, during vehicle charging, the off-board charger periodically obtains real-time electrical parameters from the vehicle battery management system; the real-time electrical parameters include charging voltage measurement values ​​and charging current measurement values; S3: During vehicle charging, the off-board charger periodically obtains its own electromechanical parameters, which correspond to real-time electrical parameters. The electromechanical parameters include the charger output voltage, the charger output current, and the cycle charge capacity. A change in the current SOC value of the vehicle battery constitutes one cycle. S4, compare the charging motor electrical parameters with the real-time electrical parameters and the initial electrical parameters. If the real-time electrical parameters are not greater than the charging motor electrical parameters and the charging motor electrical parameters are not greater than the initial electrical parameters, then charge normally and return to S2, otherwise it is determined that the battery management system has failed; compare the periodic charging capacity with the initial electrical parameters, compare the charging voltage measurement value with the charger output voltage value, and compare the charging current measurement value with the charger output current value. If the periodic charging capacity is not greater than the initial electrical parameters, the charging voltage measurement value is not greater than the charger output voltage value, and the charging current measurement value is not greater than the charger output current value, then charge normally and return to S2, otherwise it is determined that the battery management system has failed.

2. The method for detecting battery management system failure using an off-board charger according to claim 1, wherein: S1 is specifically: S11, the off-board charger obtains initial data of the vehicle battery management system; S12, obtaining initial electrical parameters according to the initial data.

3. The method for detecting battery management system failure using an off-board charger according to claim 2, wherein: The initial data includes the rated battery capacity Q 额 , rated battery voltage U 额 , Maximum allowable charging voltage U max , vehicle battery state of charge SOC 整车 and the current battery state of charge SOC 当前 .

4. The method for detecting battery management system failure using an off-board charger according to claim 3, wherein: S12 is specifically: S121, according to Q 额 and U 额 Get the total power W required by the battery 总 , W 总 =Q 额 ×U 额 / 1000 Among them, Q 额 The unit is Ah, U 额 The unit is V, W 总 The unit is KW·h; S122, obtain the theoretical charge required for each 1% SOC based on the total charge required by the battery. S123, obtain initial electrical parameters based on the theoretical charge required for each 1% SOC Among them, a=3~5.

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