Simulation of the Power Electronic Device based on MMC Structure

In this paper, the topology of power electronic transformer based on modular multilevel converter (MMC) structure was studied firstly. And a new topology was proposed that combines the power electronic transformer with energy storage system. Then, the control strategy of power electronic transformer was introduced. Finally, the simulation model of power electronic transformer based on MMC structure was built in PSCAD simulation environment. The simulation results showed that the power electronic transformer is able to ensure the voltage and current waveform of the input and output side in sinusoidal, resist load disturbance, isolate fault and isolate harmonic propagation. In addition, the battery model was also studied in PSCAD simulation environment, followed with the analysis of the influence of battery energy storage on load. The power electronic transformer topology with energy storage system proposed in this paper can guarantee both the quality and the reliability of power supply.