Research on Optimization of Distribution Network based on Power Electronic Transformer

Abstract

As the core equipment of hybrid microgrid, power electronic transformer is a new type of multifunctional transformer which integrates power electronic technology, information communication technology and control protection technology. On the background of the Beijing Low-Carbon Winter Olympics Smart Grid Demonstration Project, this paper proposed an AC/DC hybrid microgrid topology with dual-end power supply based on power electronic transformer. Moreover, a coordinated optimization control for AC/DC hybrid microgrid based on power electronic transformer is studied. The content of the paper mainly includes: The common topology of power electronic transformer is studied, and a three stage four-port power electronic transformer is proposed according to the demand of demonstration project. The interface converter topology structure and control method of distributed generation and energy storage in hybrid microgrid are analyzed, and the system model of hybrid microgrid is established. Simulation results show that MPPT control can maximize the power output of distributed generation, and piecewise droop control can realize seamless switching between power control and voltage control in the grid-tied or autonomous mode.