Dead-time Effect on the CLLC-type DC Transformer in Hybrid AC/DC Microgrid with 50% Duty Ratio Control Scheme

in the hybrid AC/DC microgrid, the DC transformer tDCT) becomes more competitive than the conventional line frequency AC transformer (ACT) to connect the AC and DC bus together with a bidirectional interlinking converter (BIC) due to the high frequency, high power density, adjustable characteristics, etc. However, the DCT exhibits the different characteristics when applied in the hybrid AC/DC microgrid. Thus, the impact on DCT induced by the switching dead-time is analyzed in this paper. The CLLC-type DCT is firstly selected to ensure the forward and backward power transmission. Aftemards; the 50% duty ration(DR) control scheme is employed to not increase the complexity of the hybrid AC/DC microgrid. Meanwhile, a systematic analysis of the DCT involving the operation principle, the input power as well as the soft-switching has also been presented with the consideration of the switch dead -time under the 50% DR control scheme. Lab-scale prototype for DCT and hybrid ACYDC microgrid have been developed for experimental verifications. All of the theoretical analysis has been experimentally verified in the full power range.