Multi-fault diagnosis method and system for battery packs based on corrected sample entropy

A multi-fault diagnosis system based on corrected sample entropy, comprising:

• a module, configured to measure cell voltages of a battery pack to be diagnosed;
• a module, configured to construct a cell voltage sequence according to the measured cell voltages of the battery pack to be diagnosed and calculate a sample entropy value of the cell voltage sequence;
• a module, configured to set a correction coefficient for representing voltage fluctuation information, and correct the sample entropy value through the correction coefficient to obtain a corrected sample entropy value;
• and
• a module, configured to judge and output a fault type of the battery pack to be diagnosed according to a numerical value change of the corrected sample entropy value;
• wherein
• the correction coefficient for representing a voltage fluctuation direction is as follows:
• when a real-time cell voltage at a time t is smaller than an average cell voltage in a sliding window N, the correction coefficient is a negative number;
• when the real-time cell voltage at the time t is larger than an average cell voltage in a sliding window N, the correction coefficient is a positive number;
• and
• when the real-time cell voltage at the time t is equal to an average cell voltage in a sliding window N, the correction coefficient is zero;
• a judging method of the module configured to judge and output the fault type of the battery pack to be diagnosed specifically comprises:
• if the corrected sample entropy value rises, judging that an over-voltage or open-circuit fault occurs;
• and
• if the corrected sample entropy value drops, judging that an under-voltage or short-circuit fault occurs.