With the trend towards vehicle electrification, three-port DC-DC converters allow an interface between the high-voltage battery pack, a 12 V battery pack and the 48 V auxiliary within the electric vehicle (EV) compared to conventional two-port converters. Due to the dependence of auxiliary loads on driving behaviour and passenger input, a robust controller is essential for a three-port converter to handle dynamically changing load profiles on the loading ports. A dual loop controller (inner current and outer voltage) is developed on a hardware demonstrator for a three port series resonant converter (TPSRC) for the voltage mode control of the loading ports (ports 2 and 3). Small signal analysis in PLECS is performed to generate the plant transfer functions for the two inner control loops. Timing delays in the closed loop implementation of a TPSRC are considered to establish sufficient phase margin in the compensator design. A soft start strategy to limit inrush currents in the TPSRC is utilized. Experimental results demonstrating the soft start strategy, voltage mode control, and step load changes on the hardware demonstrator of a 6kW TPSRC are presented.
