Improved covariance matching—electrical equivalent modeling for accurate internal state characterization of packing lithium‐ion batteries

As for the cell-to-cell inconsistency of packing lithium-ion batteries, accurate equivalent modeling plays a significant role in working characteristic monitoring and improving safety protection quality under complex conditions. In this work, novel covariance matching–electrical circuit method is proposed to realize adaptive state characterization by considering internal reaction features, an improved weighting factor correction-differential Kalman filtering model constructed iterative calculation process. A new parameter named balance introduced describe variation mathematically forming effective influence correction strategy. An matching investigated update transmit noise matrix high-power energy supply conditions, which conducted coupling relationship improve prediction accuracy. Experimental tests are verify estimation effect, closed-circuit voltage responds well corresponding battery variation. The maximum traction error 1.80%, SOC batteries 1.114% long-term experimental with MAE value 0.00481 RMSE 5.44085E-5. matching-electrical provides theoretical foundation reliable application batteries.