A modified sepic DC-DC converter for higher energy step-up conversion with fast response time based photovoltaic (PV) applications

Abstract

A single-ended primary inductor converter (SEPIC) has been modified in this work. The modification involves addition of some few components to the traditional SEPIC topology. The additional components are filter capacitor and a zener diode. The modification was done in such a way that the filter capacitor will receive the loss energy from opposite terminal of the circuit, filter it and deliver it to the zener diode. The benefits of the new topology are; higher voltage transfer ratio, less time delay and low duty ratio. Following the realization of the new topology, a prototype-based topology was created for simulation and laborary test. The simulation was carried out with MATLAB/SIMULINK. The results obtained from simulation provides a voltage value of 114V DC at the output when an input voltage value of 8V DC was applied. The results indicated a fast response time of 0.00005s by the on/off of power switch, higher voltage transfer ratio of 14.25 against a duty ratio value of 0.84. Laboratory results validated the feasibility of the simulation.