An Ultra-High Gain Quadratic Converter Based on Coupled Inductor and Switched Capacitor Techniques for DC Micro-Grid Applications

An ultra-high gain quadratic boost converter is proposed in this article. Ultra-high gain is achieved at a low duty ratio and turn ratio by using quadratic boost in combination with coupled inductor (CI) and switching capacitor techniques. The input inductor helps to achieve continuous input current with low ripple, which is recommended for photovoltaic (PV) applications. The voltage stress across switch is reduced by employing a passive clamp; thus, switch with a lower voltage rating is employed, lowering the system cost. The energy of the leakage inductor is used to achieve zero current switching (ZCS) turn-on across switch and ZCS turn-on and turn-off across all diodes, lowering switching losses. Furthermore, it helps to alleviate the diode reverse recovery problem, which further increases the efficiency of the converter. The operating principle, mathematical analysis, and comparison analysis of the proposed converter are briefly discussed. A 250-W hardware setup is designed, tested, and verified to validate the steady-state analysis.