Research on a novel hybrid transformer for smart distribution network

This paper deals with a novel hybrid power electronic transformer(HPET). Different kinds of topologies of HPET are discussed and compared. The modelling and operating principle of HPET is expounded in detail. A novel detection method based on all pass filter(APF) is proposed to detect the voltage sag. A design example is presented for a 10kV/380V, 200kVA HPET. Simulation and experiment results are discussed to verify the topology and control algorithm presented in this paper.