Modeling and Control of an Integrated Self-Heater for Automotive Batteries Based on Traction Motor Drive Reconfiguration

Lithium-ion batteries suffer from substantial capacity and power degradation in cold climates, severely deteriorating electric vehicles' performance. To solve this issue, internal heating schemes are attractive due to their high efficiency, fast speed, and uniform temperature distribution. Nevertheless, high-cost power converters and large-sized passive components are required to charge/discharge batteries alternatively, challenging onboard implementation of battery heaters. In this study, we develop an integrated battery self-heater (IBSH) based on the topology reconfiguration of traction motor drives, eliminating additional hardware. The theoretical model and operation principle of the proposed IBSH are derived for the first time, providing a feasible design and control baseline for onboard applications. Then, a robust controller is developed to adjust the heating current and cell voltage regardless of nonlinear uncertainties during self-heating. The downscaled experiments demonstrate that the proposed IBSH can effectively preheat automotive batteries with 3.45 °C/min heating speed and 0.201% SOC/°C energy consumption rate.