A Converter-Based Hybrid Transformer for Regulating the Voltage of Distribution System

This paper proposes a hybrid transformer based on partial power converter to solve the issue of voltage fluctuation in the renewable energy integration. The proposed topology consists of a series converter, a parallel converter and a three-winding line frequency transformer. The series converter functions for dynamically regulating the distribution grid voltage, while the parallel converter works for conditioning the power quality. The detail configurations, operating principles and control algorithms are illustrated. As compared to the traditional transformer, the proposal solves the issue of dynamic voltage regulation and facilitates the renewable energy integration without significantly increasing the cost. The feasibility of the proposal is verified by 220-V 1.5-kW simulations and experiments.