Method for Identifying Internal Resistance Consistency Fault in Energy Storage Battery and Energy Storage System

A method for identifying an internal resistance consistency fault in an energy storage battery, comprising:

• setting an upper limit of a cell internal resistance deviation threshold;
• determining a relationship expression of a reference internal resistance of a cell with respect to a reference temperature and a reference capacity of the cell;
• acquiring an external circuit resistance and current cell internal resistance of each battery cell;
• determining, according to the external circuit resistance and the current cell internal resistance of the each battery cell, an actual cell internal resistance of the each battery cell;
• acquiring the reference internal resistance of the cell under the reference temperature and reference capacity conditions;
• comparing actual cell internal resistances of cells with a same serial number in different battery modules with the reference internal resistances of the cell with the same serial number to obtain an internal resistance deviation value;
• and
• determining whether the internal resistance deviation value is greater than the cell internal resistance deviation threshold, and determining, in response to the internal resistance deviation value being greater than the cell internal resistance deviation threshold, that the cell is faulty.