An RMS Current Minimization Method for Three-Level ANPC-DAB-Based Distributed Energy Storage System With Full Operation ZVS
Jiachen Tian, Chaoran Zhuo, Feng Wang, Haotian Deng
Abstract
Distributed energy storage system has been developed rapidly with rising employment of sustainable energy sources. In order to withstand higher voltage, achieve larger capacity and increase control flexibility, three-level active neutral-point-clamped dual active bridge (ANPC-DAB) converter is employed for interface between energy sources and energy storage ports. In order to achieve efficient power transmission inside ANPC-DAB converter, both root-mean-square (RMS) current and zero-voltage-switching (ZVS) range are taken into consideration for further optimization. On the one hand, using fmincon function in MATLAB with multiple non-linear restrictions, optimal RMS current can be obtained to realize minimum conduction loss. On the other hand, to reduce switching loss, several typical modes are chosen to realize ZVS of all switches inside entire power range. Compared with existing modulations in three-level DAB converter, efficiency promotion strategy proposed in this paper can achieve lowest RMS current and widest ZVS range, Eventually, a ANPC-DAB prototype is established and effectiveness and correctness of proposed method can be proved.