Design Of High Step-Up DC - DC Converter For Renewable Energy Systems

Abstract

In this paper, a high step-up converter using coupled inductor with Fuzzy Logic Control is analyzed and simulated. The converter uses a coupled inductor and a switched capacitor circuit to achieve high voltage conversion ratio. Two capacitors and diodes constitute the switched capacitor circuit. The two capacitors are charged in parallel during the switch-off period and are discharged in series during the switch-on period by the energy stored in the coupled inductor to achieve a high step-up voltage gain. Switch voltage stress and the circulating current are reduced by a clamp circuit which is composed of a diode followed by a capacitor. Thus the efficiency of the converter is improved. The operating principle and the steady state analysis are discussed in detail. A Fuzzy logic controller is designed such that it eliminates the Voltage Drift problem.