An Analysis of Operation in Single-Switch High Step-up DC-DC Converter with Three-winding Coupled Inductor

The high step-up DC-DC converters are widely used in a large number of applications. Ideally, a conventional boost converter is able to achieve high step-up gain with an extreme duty ratio. In practice, the step-up gain is limited by effects of the active switch, the diode, and parasitic resistor of the inductor and the capacitor. In addition, the extreme duty ratio occurs a serious reverse-recovery problem and conduction losses. This paper presents a novel high step-up DC-DC converter, which has only one active switch. In addition, the proposed converter uses a three-winding coupled inductor. This paper describes the operation and steady state principle of the proposed converter and shows the experimental results. Accordingly, the proposed converter achieves high step-up gain with a moderate duty ratio.