Method, device and non-transitory computer-readable storage medium for online diagnosis of power battery voltage fault based on entropy algorithm

A method for online diagnosis of power battery voltage fault based on an entropy algorithm, comprising:

• (S100) obtaining a voltage time-series data of each of a plurality of cells in a battery pack of a to-be-diagnosed vehicle to construct a first voltage data matrix A;
• wherein the first voltage data matrix A is expressed by:
• A
• =
• [
• a
• 1
• ,
• 1
• a
• 1
• ,
• 2
• ⋯
• a
• 1
• ,
• n
• a
• 2
• ,
• 1
• a
• 2
• ,
• 2
• ⋯
• a
• 2
• ,
• n
• ⋮
• ⋮
• a
• i
• ,
• j
• ⋮
• a
• m
• ,
• 1
• a
• m
• ,
• 2
• ⋯
• a
• m
• ,
• n
• ]
• ;
• wherein m is a time-series length;
• n is the number of the plurality of cells;
• and ai,j represents a voltage of a j-th cell at an i-th index;
• i=1, 2, . . . m;
• and j=1, 2, . . . n;
• (S101) setting a length and a width of a sliding time window;
• and performing data interception on the first voltage data matrix A by using the sliding time window to form a second voltage data matrix B;
• (S102) subjecting voltage values of the second voltage data matrix B to data exclusion and reconstruction based on a data processing method to form a third voltage data matrix D;
• (S103) calculating a Shannon entropy value of each of the plurality of cells based on the third voltage data matrix D by using an optimized entropy algorithm;
• (S104) transforming the Shannon entropy value into a voltage abnormal fluctuation evaluation coefficient based on an improved Z-score method;
• (S105) determining whether there is an abnormal cell among the plurality of cells based on a safety evaluation strategy;
• if yes, proceeding to step (S106);
• otherwise, proceeding to step (S107);
• (S106) determining a position and an occurrence time of the abnormal cell;
• and determining an abnormality degree of the abnormal cell to send a corresponding alert to a driver;
• and
• (S107) moving the sliding time window down within the first voltage data matrix A, and repeating steps (S101)-(S105) for a next iteration.