Modular high-gain DC–DC converter for renewable energy microgrids

A novel non-isolated high-step-up high-power DC–DC converter based on coupled inductor (CI) and voltage multiplier cell (VMC) for renewable energy microgrids is presented in this paper. Hybrid combination of three-phase interleaved boost converter with three CIs is chosen to reduce the current ripple at the input and meet the high-power requirement. Three VMCs connected at the secondary side of the CIs serve as gain extension cells. The voltage stress experienced by the switches is only a fraction of the output voltage as the gain extension is mainly achieved at the secondary side of CIs. Practical results obtained from the proposed converter, which operates from a 60 V input and provides an output voltage of 1.1 kV while delivering 3 kW of output power at 92.6% efficiency, validate the proposed concept and design hypothesis.