FPGA based Fuzzy Logic Control for Single Phase Multilevel Inverter

A single phase cascaded inverter consisting of two full bridges creates a five level AC output voltage. Due to switch combination redundancies, there are certain degrees of freedom to generate the five level AC output voltage. A single phase Pulse Width Modulation (PWM) Multil Level Inverter (MLI) produces AC output voltage of desired magnitude and frequency. The purpose of voltage controller for the inverter is to produce regulated output voltage with low distortion under all loading conditions. In this paper, the objective of reducing the THD of output of the chosen five level cascaded inverter under steady-state as well as set point tracking with fast transient response are approached from control point of view. A Fuzzy Logic Controller (FLC) is developed using Matlab-Simulink and implemented using Field Programmable Gate Array (FPGA) for the chosen inverter. For comparison purposes, a PI controller is also developed and implemented. The results are presented and analysed.