A high step‐up coupled‐inductor‐based dc‐dc converter with a wide duty cycle range and improved gain‐to‐element ratio

Abstract

Abstract Most high‐gain step‐up dc‐dc structures operate with a limited duty cycle and suffer from a high component count, limiting their application. This paper addresses these problems by proposing a new step‐up dc‐dc converter that provides a high conversion ratio with few elements. Two coupled inductors are used instead of conventional voltage multiplier cells to improve the gain without excessive components. The topology includes one switch whose duty cycle is not limited and can vary between zero and one according to the output voltage condition. It has been placed on the low‐voltage side of the converter that encounters low‐voltage stress. It is selected from low‐voltage rating switches with small on‐resistance, which reduces the conduction loss of the switch and improves the efficiency. High boost factor, high efficiency, reasonable component counts, improved gain‐to‐element ratio, and low voltage stress on the switch distinguishe the converter from their counterparts. The topology also benefits from the common‐ground feature. However, its input current waveform is pulsating. This article describes the theory and operation principle of the topology in detail. Experimental results are represented to evaluate the converter's performance and operation. In this case, a 240 W prototype has been designed and fabricated. Results confirm the above claims.

Keywords

• DC‐DC power convertors
• power electronics