A new simplified cascaded boost converter for high ratio and low ripple application

A high voltage ratio DC-DC boost converter is commonly used in PV and fuel cell power generation systems. To obtain a high voltage ratio, several topologies were proposed. Low voltage ripples are also desirable in most of applications. The effects of current ripple on PV power generation systems have been investigated in. Current ripple moves the operating point of photovoltaic towards the constant voltage region of the PV characteristic, resulting in a sharp decline in the average power. No works have shown how to obtain simultaneously a high voltage ratio and low current ripples. In this paper, a simplified cascaded boost converters for high voltage ratio and low ripple applications is proposed. The proposed topology is suitable to be used for PV and fuel cell power generation system. The proposed topology is simplified version of cascaded connection of single phase boost converter and multiphase boost converter. High voltage ratio can be achieved by cascade feature of the boost converters. The proposed simplified topology will increase the effective switching frequency on the input side of the converter. Therefore it will reduce the input current ripple. By using the proposed topology, high voltage ratio and low ripples can be simultaneously achieved without using a high number of switching devices. The proposed method is verified by using analytical and experimental results.