PSO-based Current Stress Optimization for Three-Level Dual Active Bridge DC-DC Converters

Dual-active-bridge (DAB) DC-DC converter is widely adopted and applied for renewable systems as the power interface considering the fluctuation of the output voltage and power from distributed generators. In order to adapt to high voltage and high power application, three-level diode neutral-point-clamed (3L-DNPC) DAB DC-DC converter has been intensively discussed considering its small electromagnetic interference and wide voltage endurance range. Aiming to improve the efficiency of this 3L-DNPC based DAB converter under all conditions, this paper shows an optimization method to reduce the switch current stress under dual-phase shift modulation strategy. Based on particle swarm optimization (PSO), the proposed control becomes simplified and effectiveness for a wide range. Main simulation and experimental results are provided in order to validate the outstanding performance of the proposed optimization method.