A soft switched high step‐up DC‐DC converter based on VMC and coupled inductor for photovoltaic energy applications

Abstract

Abstract In this paper a new topology of non‐isolated high step‐up DC‐DC is proposed for renewable applications like photovoltaic (PV) power generation. This converter is designed based on coupled inductor and VMC techniques. The main benefits of the presented topology are: (1) Continues input current with low ripple, (2) low voltage stress across semiconductors, (3) soft switching of diodes (ZVS and ZCS), (4) high voltage gain with low duty cycle, (5) low volume and cost, and (6) high power efficiency. To obtain a high output voltage, the secondary side of the coupled inductor is integrated with VMC, resulting in a large voltage gain with low duty cycles and reduced conduction loss of power switches. Additionally, diodes' zero voltage switching (ZVS) and zero current switching (ZCS) improve the efficiency of the proposed converter. The used VMCs act as a voltage clamp, and the peak voltages across power switches are reduced. The presented converter's operational modes, steady‐state, and efficiency analysis are discussed. Additionally, to indicate the performance of the suggested structure, a 200 W prototype with Vin = 33 V and Vo = 403 V voltage conversion is built, and the experimental results are presented. The experimental efficiency at Po = 200 W is measured 95.29%. Also, efficiency is measured more than 95 % for Po = 20 W to 200 W.

Keywords

• DC‐DC power convertors
• electric power generation
• renewable energy power conversion