基于固态变压器的移动变电站综合性能提升方法

In order to reduce the volume and weight of the main transformer, and to improve the input power quality of mobile substation, this paper proposes a solid state transformer topology used in the mobile substation. The proposed mobile substation comprises a AC-AC converter, high-frequency multi-pulse rectifier, and a line-frequency inverter. The operating principle of the AC-AC converter is analyzed, and its control strategy is designed from reducing its switching losses. The phase-shifting transformer used in the high-frequency multi-pulse rectifier is designed from the symmetry of magnetic and electric circuit, and the input current and output voltage of the solid state transformer are also calculated based on the switching function. The control and drive circuit of the AC-AC converter is designed, and the scaling simulation and experimental platform is also setup. The simulation and experimental results show that volume of the main transformer reduced to 1/3 of that of the line frequency transformer under the same kV•A rating; after using the phase-shifting transformer, the THD of the input line current decreases from 22% to 16%.