A Compact Onboard Battery Self-Heater for All-Electric Aircraft Applications at Cold Climates

The concept of all-electric aircraft (AEA) is fascinating due to its zero emissions and lower operation cost. As the primary power source of AEAs, the lithium-ion batteries suffer severe capacity and power degradation at subzero temperatures, leading to serious "range anxiety" in winter. Therefore, the onboard battery preheating equipment is essential for AEAs at cold climates. In this digest, an interleaved resonant onboard battery self-heater is developed for internally preheating the batteries without external power supplies, thereby providing great flexibility for AEAs at different apron areas. By properly adjusting the switching frequency, the self-heater can achieve the zero-current-switching (ZCS) to improve the energy consumption and eliminate the voltage spikes during the turn-off. Meanwhile, a detailed guideline for optimizing the resonant tank parameters is presented so that the efficiency of the self-heater can be further developed by reducing the circulating current. The experimental validation on 18650 cells demonstrates the proposed heater can preheat the battery from -20°C to 0°C within only 3.5 minutes, and only consume 5% of the cell energy.