New tri-switching state non-isolated high gain DC-DC boost converter for microgrid application

Abstract

High efficiency is an important requirement from DC-DC converter in DC microgrid system when integrated with renewable energy sources. This study proposes a new tri-switching state non-isolated high gain boost converter for 400 V DC microgrid applications. The proposed converter developed by modifying the conventional boost converter with advantageous features such as; high-voltage gain operation with two different duty pulses to overcome the restriction of high duty ratio and continuous input current. Moreover, semiconductor components in the proposed converter are subjected to reduced voltage stress for a shorter duration when compared to conventional existing topologies. Steady state (with and without non-idealities consideration) and performance analysis are presented to validate the viability of the proposed converter for high gain operation in grid-connected systems. For experimental validation, a prototype model of the proposed converter is developed for 31 V/400 V, 500 W and operated at 50 kHz switching frequency. The converter is tested for a power range of 100-500 W for two different duty range (case: 1-k1 kept fixed and k2 is varied, case: 2-k2 kept fixed and k1 is varied) to validate the consistency in output voltage. Hardware results obtained validates superior performance and higher efficiency compared to conventional existing topologies. - The Institution of Engineering and Technology 2019.