Analysis, design, and experimental verification of high step-up DC-DC converter to interface renewable energy sources into DC nanogrid

This paper proposes a new non-isolated, high step-up DC-DC converter to interface renewable sources into DC microgrid. The topology utilizes the coupled inductor and switched capacitor techniques to achieve high step-up voltage conversion ratio. The leakage energy is directly transferred to output to avoid voltage spikes across the switch. The switching devices have relatively low voltage stresses. In addition, the coupled inductor alleviated the reverse recovery problem of the diode. The key features include high efficiency, low voltage stresses, and low component count and cost. The steady-state analysis and operation of the proposed converter are presented in detail. Finally, a 200 W prototype circuit operating at a switching frequency of 100 kHz is built in the laboratory to verify the performance. The experimental results substantiate the theoretical analysis and show a peak efficiency of 96.90%.