Swarm Intelligence Aided Parameter Design for the Symmetrical CLLC-Type DAB Converter with Robust Voltage Conversion Gain

The symmetrical CLLC-type DAB converter has become more popular as a DC transformer (DCT) in the DC microgrid for its galvanic isolation, high power efficiency and high power density. As a DCT, the CLLC-type DAB converter is expected to regulate the DC voltages on the bus and keep a robust voltage conversion gain (VCG). However, because of the practical values of the inductors and capacitors may fluctuate with varying temperature and operating power, VCG of the CLLC-type DAB converter may deviate from the designed one, negatively affecting power supplies. Therefore, this paper proposes a swarm intelligence aided parameter design approach for the CLLC-type DAB converter to ensure its robust VCG against fluctuating inductors and capacitors. In this design approach, the particle swarm optimization (PSO) algorithm is adopted to facilitate design process with high accuracy and computational speed. Finally, the effectiveness of the proposed design approach has been verified with experiments.