A temperature estimation method for lithium-ion batteries

The temperature estimation of lithium-ion batteries is crucial for the safe operation of energy storage power stations. While existing thermal models for lithium-ion batteries can accurately estimate the temperature state of batteries, the estimation time is too long to meet the engineering requirements of timeliness. This paper focuses on the 280Ah square energy storage lithium-ion battery. Firstly, a variable-parameter secondorder equivalent circuit model and a variable-parameter thermal circuit model were established, and then a variable-parameter thermal circuit-circuit coupling model was established based on the coupling relationship between current, internal resistance, power, SOC (state of charge) and temperature. Secondly, the parameter identification of the model was accomplished using the least squares algorithm based on the data from the Hybrid Pulse Power Characterization experiment. Finally, the model is verified by the experimental conditions and the actual operating conditions of the energy storage station. The error between the temperature estimated by the model and the actual temperature is less than $0.3^{\circ} \mathrm{C}$, and 2.97s can accomplish the temperature estimation of a single lithium-ion battery for one day of actual work.