EP-4571340-B1 - BATTERY VOLTAGE ACQUISITION FAULT EARLY WARNING METHOD AND SYSTEM

EP4571340B1EP 4571340 B1EP4571340 B1EP 4571340B1EP-4571340-B1

Inventors

WANG, Yongshi
SHEN, JIAN
XIE, HUI
ZHU, Jinxin
HUANG, MIN
LIU, Zhenyong
WANG, JUNJUN
LU, FANG
ZHANG, Shutao
LIU, KAI

Dates

Publication Date: 20260506
Application Date: 20230214

Claims (15)

A fault warning method for battery voltage acquisition, comprising steps of: acquiring (S100), within a preset monitoring duration, a total voltage of a battery system at each frame of time and acquiring an effective battery cell voltage of each battery cell; calculating (S200) a number of frames with abnormal voltage data based on the preset monitoring duration, the total voltage of the battery system and each effective battery cell voltage; calculating (S300) a total number of frames in the preset monitoring duration, and calculating a ratio of the number of frames with abnormal voltage data to the total number of frames, and if the ratio is greater than or equal to a preset proportion threshold, identifying an abnormal battery cell from respective battery cells and issuing a sampling fault warning signal.
The fault warning method for battery voltage acquisition according to claim 1, wherein the step of "calculating (S200) a number of frames with abnormal voltage data based on the preset monitoring duration, the total voltage of the battery system and each effective battery cell voltage" comprises steps of: traversing (S210) each frame within the preset monitoring duration, calculating, based on each effective battery cell voltage at a current frame, a voltage reference value of the battery cell and calculating a first difference value between each effective battery cell voltage and the voltage reference value, and counting a first number of battery cells with the first difference value being greater than a preset difference value; calculating (S220) a second difference value between the total voltage of the battery system and a total effective voltage of all battery cells, and if a ratio of the second difference value to the first number is greater than or equal to the preset difference value, determining that the current frame is a frame with abnormal voltage data; calculating (S230), based on the preset monitoring duration and the frame with abnormal voltage data, the number of frames with abnormal voltage data.
The fault warning method for battery voltage acquisition according to claim 2, wherein the first difference value comprises a median difference or a voltage average, and the step of "calculating (S210), based on each effective battery cell voltage at a current frame, a voltage reference value of the battery cell and calculating a first difference value between each effective battery cell voltage and the voltage reference value, and counting a first number of battery cells with the first difference value being greater than a preset difference value" comprises a step of: calculating, based on each effective battery cell voltage at the current frame, a median voltage of all effective battery cell voltages and calculating a median difference between each effective battery cell voltage and the median voltage, and counting the first number of battery cells with the median difference being greater than the preset difference value; or calculating, based on each effective battery cell voltage at the current frame, an average voltage of all effective battery cell voltages and calculating an average difference between each effective battery cell voltage and the average voltage, and counting the first number of battery cells with the average difference being greater than the preset difference value.
The fault warning method for battery voltage acquisition according to claim 3, wherein the step of "calculating (S220) a second difference value between the total voltage of the battery system and a total effective voltage of all battery cells, and if a ratio of the second difference value to the first number is greater than or equal to the preset difference value, determining that the current frame is a frame with abnormal voltage data" comprises steps of: calculating, based on the total voltage Volt total of the battery system and the total effective voltage Volt1 total of all the battery cells, the second difference value volt off between the total voltage Volt total of the battery system and the total effective voltage Volt1 total of all the battery cells: volt off = Volt total − Volt 1 total = Volt total − ∑ i = 1 n Cell i if a ratio of the second difference value volt off to the first number N is greater than or equal to the preset difference value volt t h r : volt off N ≥ volt t h r determining that the current frame is a frame with abnormal voltage data; wherein in equation (1), Cell i is a voltage of an i-th battery cell, and n is a total number of the battery cells.
The fault warning method for battery voltage acquisition according to claim 3, wherein the step of "calculating (S300) a total number of frames in the preset monitoring duration, and calculating a ratio of the number of frames with abnormal voltage data to the total number of frames, and if the ratio is greater than or equal to a preset proportion threshold, identifying an abnormal battery cell from respective battery cells" comprises a step of: calculating the total number of frames in the preset monitoring duration, and calculating the ratio of the number of frames with abnormal voltage data to the total number of frames, and if the ratio is greater than or equal to the preset proportion threshold, determining, from the respective battery cells, that a battery cell, with a highest occurrence number of a maximum median difference or a maximum average difference at a single frame of time within the preset monitoring duration, is the abnormal battery cell.
The fault warning method for battery voltage acquisition according to claim 1, wherein the step of "acquiring (S100) an effective battery cell voltage of each battery cell" comprises steps of: acquiring (S110) an initial voltage of each battery cell; if the initial voltage of the battery cell is within a preset voltage range, taking (S120) the initial voltage of the battery cell as the effective battery cell voltage; if the initial voltage of the battery cell is out of the preset voltage range, issuing (S130) the sampling fault warning signal.
The fault warning method for battery voltage acquisition according to claim 2, wherein the preset difference value is set to 0.2V and the preset proportion threshold is set to 10%.
A fault warning system for battery voltage acquisition (100), comprising: a voltage acquisition module (110), configured to acquire, within a preset monitoring duration, a total voltage of a battery system at each frame of time and acquire an effective battery cell voltage of each battery cell; a module for acquiring a number of frames with abnormality (120), connected with the voltage acquisition module (110) in a communication way and configured to calculate a number of frames with abnormal voltage data based on the preset monitoring duration, the total voltage of the battery system and each effective battery cell voltage; an abnormal battery cell module (130), connected in a communication way with the voltage acquisition module (110) and the module for acquiring a number of frames with abnormality (120), and configured to: calculate a total number of frames in the preset monitoring duration, and calculate a ratio of the number of frames with abnormal voltage data to the total number of frames, and if the ratio is greater than or equal to a preset proportion threshold, identify an abnormal battery cell from respective battery cells and issue a sampling fault warning signal.
The fault warning system for battery voltage acquisition (100) according to claim 8, wherein the module for acquiring a number of frames with abnormality (120) is configured to: traverse each frame within the preset monitoring duration, calculate, based on each effective battery cell voltage at a current frame, a voltage reference value of the battery cell and calculate a first difference value between each effective battery cell voltage and the voltage reference value, and count a first number of battery cells with the first difference value being greater than a preset difference value; calculate a second difference value between the total voltage of the battery system and a total effective voltage of all battery cells, and if a ratio of the second difference value to the first number is greater than or equal to the preset difference value, determine that the current frame is a frame with abnormal voltage data; calculate, based on the preset monitoring duration and the frame with abnormal voltage data, the number of frames with abnormal voltage data.
The fault warning system for battery voltage acquisition (100) according to claim 9, wherein the first difference value comprises a median difference or a voltage average, and the module for acquiring a number of frames with abnormality (120) is further configured to: calculate, based on each effective battery cell voltage at the current frame, a median voltage of all effective battery cell voltages and calculate a median difference between each effective battery cell voltage and the median voltage, and count the first number of battery cells with the median difference being greater than the preset difference value; or calculate, based on each effective battery cell voltage at the current frame, an average voltage of all effective battery cell voltages and calculate an average difference between each effective battery cell voltage and the average voltage, and count the first number of battery cells with the average difference being greater than the preset difference value.
The fault warning system for battery voltage acquisition (100) according to claim 10, wherein the module for acquiring a number of frames with abnormality (120) is further configured to: calculate, based on the total voltage Volt total of the battery system and the total effective voltage Volt1 total of all the battery cells, the second difference value volt off between the total voltage Volt total of the battery system and the total effective voltage Volt1 total of all the battery cells: volt off = Volt total − Volt 1 total = Volt total − ∑ i = 1 n Cell i if a ratio of the second difference value volt off to the first number N is greater than or equal to the preset difference value volt t h r : volt off N ≥ volt t h r determine that the current frame is a frame with abnormal voltage data; wherein in equation (1), Cell i is a voltage of an i-th battery cell, and n is a total number of the battery cells.
The fault warning system for battery voltage acquisition (100) according to claim 10, wherein the abnormal battery cell module (130) is configured to: calculate the total number of frames in the preset monitoring duration, and calculate the ratio of the number of frames with abnormal voltage data to the total number of frames, and if the ratio is greater than or equal to the preset proportion threshold, determine, from the respective battery cells, that a battery cell, with a highest occurrence number of a maximum median difference or a maximum average difference at a single frame of time within the preset monitoring duration, is the abnormal battery cell.
The fault warning system for battery voltage acquisition (100) according to claim 8, wherein the voltage acquisition module (110) is further configured to: acquire an initial voltage of each battery cell; if the initial voltage of the battery cell is within a preset voltage range, take the initial voltage of the battery cell as the effective battery cell voltage; if the initial voltage of the battery cell is out of the preset voltage range, issue the sampling fault warning signal.
The fault warning system for battery voltage acquisition (100) according to claim 9, wherein the preset difference value is set to 0.2V and the preset proportion threshold is set to 10%.
A computer-readable storage medium, storing a computer program which, when executed by a processor, enables the processor to implement the method according to any one of claims 1 to 7.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese application No. 202211056283.2, filed on August 31, 2022 and entitled "Fault Warning Method and System for Battery Voltage Acquisition". TECHNICAL FIELD The present disclosure relates to the field of battery safety and, in particular, to a fault warning method and system for battery voltage acquisition. BACKGROUND Safety of batteries has become an increasing social concern in recent years, and as a battery nanny or a battery manager, a battery management system, BMS, is mainly used for intelligent management and maintenance of various battery units, preventing over-charging and over-discharging of the batteries, extending the service life of the batteries, and monitoring status of the batteries. If battery voltage information acquired by the battery management system, BMS, is incorrect, the battery management system will be seriously affected in terms of its normal operation, and therefore the batteries would be under safety hazards. When determining that there is a fault in voltage sampling of a battery, generally, the existing battery management system, BMS, only judges a value of the voltage sampling of the battery that is lost or exceeds a range. Authenticity cannot be determined for the value within the range and it is impossible to know whether there is abnormal voltage sampling data. Prior art document CN108931725A discloses battery voltage monitoring for a battery stack with plural cells, involving measuring the total stack voltage, measuring the cell voltages, and comparing the total stack voltage to the sum of the cell voltages to indicate a fault in a battery cell and, particularly, in the voltage sensing circuitry itself. SUMMARY The present disclosure provides a fault warning method and system for battery voltage acquisition, according to which an abnormal battery cell can be timely obtained and a sampling fault warning signal can be issued, to enable a battery to be in a safe operation state. In a first aspect of the present disclosure, a fault warning method for battery voltage acquisition is provided, which includes steps of: acquiring, within a preset monitoring duration, a total voltage of a battery system at each frame of time and acquiring an effective battery cell voltage of each battery cell; calculating a number of frames with abnormal voltage data based on the preset monitoring duration, the total voltage of the battery system and each effective battery cell voltage; calculating a total number of frames in the preset monitoring duration, and calculating a ratio of the number of frames with abnormal voltage data to the total number of frames, and if the ratio is greater than or equal to a preset proportion threshold, identifying an abnormal battery cell from respective battery cells and issuing a sampling fault warning signal. In a second aspect of the present disclosure, a fault warning system for battery voltage acquisition is provided, including: a voltage acquisition module, configured to acquire, within a preset monitoring duration, a total voltage of a battery system at each frame of time and acquire an effective battery cell voltage of each battery cell; a module for acquiring a number of frames with abnormality, connected with the voltage acquisition module in a communication way and configured to calculate a number of frames with abnormal voltage data based on the preset monitoring duration, the total voltage of the battery system and each effective battery cell voltage; an abnormal battery cell module, connected in a communication way with the voltage acquisition module and the module for acquiring a number of frames with abnormality, and configured to: calculate a total number of frames in the preset monitoring duration, and calculate a ratio of the number of frames with abnormal voltage data to the total number of frames, and if the ratio is greater than or equal to a preset proportion threshold, identify an abnormal battery cell from respective battery cells and issue a sampling fault warning signal. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows an exemplary flowchart of a fault warning method for battery voltage acquisition according to some embodiments of the present disclosure.FIG. 2 shows an exemplary flowchart of a fault warning method for battery voltage acquisition according to other embodiments of the present disclosure.FIG. 3 shows an exemplary flowchart of a fault warning method for battery voltage acquisition according to yet other embodiments of the present disclosure.FIG. 4 shows an exemplary structural diagram of a fault warning system for battery voltage acquisition according to some embodiments of the present disclosure. Description of drawings: 100: fault warning system for battery voltage acquisition; 110: voltage acquisition module; 120: module for acquiring a number of frames with abnormality; 130: abnormal battery cell module. DESCRIPTION OF EMBODIMENTS Now, with detailed