Battery State of Power Estimation

This chapter mainly covers the definition of state of power (SOP) and its estimation method. As the SOP describes the transient response to the external load changes, it is necessary to carry out the SOP estimation of lithium-ion batteries. There are two methods to estimate battery SOP: One is based on interpolation, and the other on parameter modeling. Interpolation has the advantages of simplicity and no complex algorithm. It requires a lot of memory and is not suitable for SOP estimation under dynamic conditions. For different models, the difficulty and accuracy of parameter estimation are different. In addition, the model changes along with the parameter variation, so the temperature in the battery equivalent circuit model should be considered when using this method. The SOP of lithium-ion batteries is estimated to describe the peak charge-discharge power in the current state. The charge-discharge limit capacity is evaluated by estimating the peak power of the batteries, which has great significance to electric vehicles.