Analyzing Dynamic Heat Generation Characteristics of Battery Cell Using Equivalent Circuit Method

초록

High power battery modules with high energy density are vulnerable to thermal runaway. Therefore, a cooling system is required to maintain a safe temperature. To predict the thermal behavior of a module prior to designing for heat dissipation, the heat fluctuations generated in the cell based on the input current, ambient temperature, and SoC(state of charge) should be reflected precisely. Considering the high cost of numerical analysis of electrochemical cells, a thermal analysis of a battery was performed in this study using a secondary equivalent circuit model. This model predicts the amount of heat by deriving the resistance and capacitance variables of specific SoC from pulse discharge data. Using thermal conduction analysis, the results of numerical analysis under constant current discharge at various C-rates and actual electric-vehicle driving conditions were compared with the experimental results in terms of equivalent properties, and the effectiveness of the secondary equivalent circuit-based thermal analysis was analyzed.

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