Method and system for detecting faults of power batteries

Abstract

The invention provides a method and a system for detecting faults of power batteries. The system comprises a voltage detection circuit, a window comparison circuit, a control unit, a time control unit, an analog-to-digital conversion circuit and a control circuit, wherein the voltage detection circuit detects a voltage value of a single battery; the window comparison circuit compares the detectedvoltage values respectively and judges whether the detected voltage values fall in the first threshold value range; the control unit controls an actuator to cut off a charge-discharge circuit or givean alarm when the voltage value of any single battery does not fall in the first threshold value range; the time control unit controls the preset interval time for voltage detection; when the voltagevalues fall in first threshold value range, the analog-to-digital conversion circuit converts the voltage values into voltage digital signals to be inputted in a temporary storage module, and an MCU secondary comparison unit selects the maximum voltage value and the minimum voltage value from the voltage values to perform the secondary comparison and judges whether the difference value of the maximum voltage value and the minimum voltage value falls in the second threshold value range; and when the difference value of the maximum voltage value and the minimum voltage value does not fall in the second threshold value range, the control circuit controls the actuator to cut off the charge-discharge circuit or give an alarm. By using the detection system and the detection method provided by the invention, the power batteries are guaranteed to have higher safety.

Description

technical field [0001] The invention relates to a fault detection method for a power battery, especially a power battery group composed of a plurality of individual batteries connected in series, and a detection system for realizing the method. Background technique [0002] Existing power batteries are mainly used in hybrid vehicles or pure electric vehicles, and are favored by various vehicle manufacturers because of their low-carbon and environmental protection advantages. Therefore, power batteries composed of lithium battery packs or iron-lithium battery packs are being studied in depth and are also being tried on some vehicles. Such as pure battery car and so on. This kind of battery pack consists of multiple batteries connected in series. If one of the individual batteries fails, it will affect the use of the entire power battery. In severe cases, the battery will explode, causing damage to personnel and vehicles. [0003] In order to prevent the occurrence of the ab...

AI Technical Summary

Problems solved by technology

This method of detection, due to the wide predetermined voltage range (3.0V-4.2V) and the individual batteries with low voltage, it is assumed that the voltage of one of the batteries is only 3.1V or 3.2V, and the voltage of most of the batteries is indeed at A higher value, such as 4.1V or 4.2, is judged as qualified and can be used continuously. However, in a battery pack, the battery with low voltage is often a battery with inherent hidden dangers inside the battery, and the existing detection circuit is indistinguishable

This kind of battery with inherent hidden dangers may cause the explosion of the battery, and then cause the explosion of other batteries in the battery pack, and more seriously, it will affect the life of the entire vehicle.

And if the predetermined voltage range is set to be narrower, this will cause the battery pack to be stopped from use too frequently, and the practical effect cannot be achieved.

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