Fuzzy logic control for a grid-connected PV array through Z-source-inverter using maximum constant boost control method

Abstract

Abstract The paper presents an alternative scheme using fuzzy logic methodology to control a grid-connected photovoltaic system through ZSI using MCBC method. The system model and control are implemented using MATLAB-SIMULINK simulation toolbox. In view of control, Fuzzy Logic Controllers (FLCs) are designed to enhance the system stability. To ensure a unity power factor operation, the inverter modulation index is controlled to manage the phase current of the grid. Also, the control in the shoot-through ratio controls the output voltage of the PV array, so the maximum power (MP) is extracted. The simulation results using FLCs are compared with others obtained using Proportional Integral (PI) controllers. This is under the same normal operating and transient conditions which are irradiation variation, three-phase short circuit fault at point of connection and voltage variation of the grid. The simulation results of FLCs achieve supplementary enhancement of the system stability over various operating conditions.