Load Voltage Regulation Strategy for Hybrid Power Transformers considering Voltage Fluctuations in Power Grid

This article studies the use of hybrid power transformers to solve the problem of load voltage disturbance caused by grid side voltage fluctuations. A new hybrid power transformer circuit topology scheme is designed, which includes three independent H-bridge converters (HBC) and a three-phase full-bridge voltage source converter (TPFBVSC). The equivalent mathematical models of HBC and TPFBVSC as well as the overall mathematical model of the transformer were established. Based on the model, a load side voltage regulation strategy and a DC voltage stability control strategy of three-phase full bridge voltage source converter for H-bridge converters are proposed. The strategy can solve the problems of load voltage fluctuations and three-phase imbalance caused by grid side phase voltage fluctuations.