A 31 Level Multilevel Inverter Topology For A Grid Connected System Using Fuzzy Logic Controller

Abstract

This paper presents a novel 31-level multilevel inverter (MLI) topology for grid-connected renewable energy systems, integrated with a Fuzzy Logic Controller (FLC) to enhance system performance and power quality. The proposed inverter architecture significantly reduces the number of power switches and passive components compared to conventional topologies, achieving a high-resolution output with minimal complexity. By producing a near-sinusoidal voltage waveform, the 31-level inverter minimizes Total Harmonic Distortion (THD) and ensures compliance with IEEE-519 harmonic standards. To address the challenges of grid variability and nonlinear load dynamics, a Fuzzy Logic Controller is implemented to optimize the modulation index and switching signals in real-time. Unlike traditional PI controllers, the FLC offers robustness against parameter variations and improves dynamic response under transient and unbalanced conditions. The controller uses input variables such as error and change in error to generate control actions that enhance inverter output stability and grid synchronization. Extensive simulations conducted in MATLAB/Simulink validate the effectiveness of the proposed system. Results demonstrate superior voltage waveform quality, reduced THD (below 3%), fast dynamic response, and reliable operation under varying load and input conditions. The combination of a high-performance 31-level inverter and intelligent fuzzy-based control makes the proposed system highly suitable for modern grid-connected applications, including solar PV, wind energy systems, and smart grid interfaces