Design considerations of a multiple-input isolated single ended primary inductor converter (SEPIC) for distributed generation sources

This paper explores the multiple-input isolated single ended primary inductor converter (MIISEPIC) and discusses its design considerations for low power distributed generation (DG) sources, such as PV modules. The paper first analyzes the operation of the MIISEPIC, investigates controllable input current ranges that can affect current loop design, such as maximum power point control, and discusses tradeoffs between achievable input current ranges and converter efficiency. Moreover, a novel driving strategy is proposed to improve efficiency and operational flexibility. A proper coupled-inductor design is suggested to minimize switching losses caused by its leakage inductance. A zero-ripple technique is applied to the MIISEPIC to increase its lifetime. Experimental results are provided to validate the analysis.