Isolated bidirectional DC/AC and AC/DC three-phase power conversion using series resonant converter modules and a three-phase unfolder

This paper proposes a modular converter system to achieve high power density, high system bandwidth and scalability for isolated bidirectional DC/AC and AC/DC three-phase power conversion. The approach is based on high frequency isolated series resonant converter (SRC) modules with series output connection and a low frequency three-phase unfolder. The performance objectives are realized through elimination of traditional low frequency passive filters used in PWM inverters and instead require high control bandwidth in the SRC modules to achieve high quality AC waveforms. The system operation and performance are verified with simulation and experimental results for a 1 kW prototype.