A Three-Port Hybrid Transformer With Partial Power Processing Function for Renewables and Energy Storage Integration

Integrating energy storage system (ESS) with renewables can smoothen the power flow and mitigate the impacts on the grid. A novel hybrid transformer (HT) featuring partial power processing (PPP) function and multiplexing of converter unit is proposed for the integration. The operational fundamentals, such as conversion modes, operating range, and control strategy, are discussed in the work. Performances such as the unit power rating and port capacity, processing power ratio, and efficiency are analyzed. Compared with the typical two-stage configuration, the total unit power rating to obtain a defined port capacity is significantly reduced, which leads to a decrease in the cost. The efficiency and the maximal converting capacity of the ESS port are both enhanced. Calculations, simulations, and experiments are completed and compared to verify the improvement.