Investigation on Fuzzy Logic Based Centralized Control in Four-Port SEPIC/ZETA Bidirectional Converter for Photovoltaic Applications

Abstract

In this paper, a new four-port DC-DC converter topology is proposed to interface renewable energy sources and the load along with the energy storage device. The proposed four-port SEPIC/ZETA bidirectional converter (FP-SEPIC/ZETA BDC) converter comprises an isolated output port with two unidirectional and one bidirectional input ports. This converter topology is obtained by the fusion of SEPIC/ZETA BDC and full-bridge converter. This converter topology ensures the non-reversal of output voltage hence it is preferred mostly for battery charging applications. In this work, photovoltaic (PV) source is considered and the power balance in the system is achieved by means of distributed maximum power point tracking (DMPPT) in the PV ports. The centralized controller is implemented using fuzzy logic controller (FLC) and the performance is compared with conventional proportional integral (PI) controller. The results offer useful information to obtain the desired output under line and load regulations. Experimental results are also provided to validate the simulation results.

Keywords

• bidirectional power flow
• DC-DC power converters
• fuzzy control
• photovoltaic systems
• pi control