Fuzzy Logic Controlled SEPIC Re-Lift Converter System - A Comparative Study

Abstract

Voltage lift cascaded DC/DC converters are generally used to feed low power DC drives and batteries. This paper deals with the modelling, the simulation and the comparison of voltage lifted Single Ended Primary Inductor Converter (SEPIC) cascaded soft switched converter systems. The objective of this work is to improve the voltage gain and the efficiency of the voltage lifted SEPIC converter. Auxiliary switch with capacitor clamping is added in order to obtain the soft switching. SEPIC in self-lift and re-lift modes are simulated and the corresponding results are presented. The performance of the converter is studied in terms of output power and ripple voltage. Design and simulation results are presented in order to identify a cascaded system with high power output. The comparative study is presented in order to demonstrate the reduction in the ripple in the output voltage. The advantages of the proposed converter are high voltage gain, reduced switching loss and low electromagnetic interference (EMI). The open loop systems with fluctuating input voltages are simulated. Closed loop systems with proportional integral controller and Fuzzy Logic Controller (FLC) are simulated and their results are compared. Comparing the results, it can be observed that the time response has been improved in terms of settling time and steady state error.