Research on control of civil aircraft battery system based on bidirectional DC/DC converter

In this paper, a third-order nonlinear dynamic model of lead-acid battery is firstly established to simulate dynamic relationship among SOC (State of Charge), DOC (Depth of Charge), battery voltage, and charge-discharge current based on nonlinear and temperature characteristics of battery. Then, the bidirectional half-bridge converter is adopted as DC/DC conversion circuit combined with battery to realize bidirectional energy flow and improve energy utilization efficiency. Subsequently, the SOC-based stage charging method is used to shorten charge time, save electricity and extend service life. Moreover, discharge method based on constant voltage is adopted to guarantee power supply stability, which is helpful to reduce start-up impact of aircraft heavy load and improve power quality. Finally, system model is set up in MATLAB/Simulink to verify the correctness of theoretical analysis and control methods.