A Novel 21 Level Switched Capacitor Modular Multilevel Inverter Using Gray Wolf Optimization

Abstract

This paper introduces the design and development of a modular switched multilevel inverter with a reduced number of components. Conventional multilevel inverters (MLIs), owing to its achievement and widespread uses in industries, there have been many advancements and improvement of novel topologies. This study generalizes the basic unit of a switched capacitor topology using a cascaded H-bridge structure to realize a switched capacitor multilevel inverter (SCMLI). This paper proposes a single phase 21-level inverter topology with floating capacitor unit meeting aforementioned requirements. The major objective of this study is to propose a topology to attain higher levels with a reduced number of switches. Further, three optimization techniques namely Ant Lion Optimization (ALO), Equilibrium Optimizer (EO) and Gray Wolf Optimization (GWO) to control the inverter switching angle are studied and compared. The optimum switching angles of the SC-MLI to generate the required fundamental voltage is identified using GWO. The performance of the proposed inverter is investigated in terms of output voltage, Total harmonic distortion (THD), switching and conduction losses. The stress on switching components due to switching and conduction losses is analysed. In MATLAB/Simulink, the simulations are performed and control strategy is implemented in digital platform using a Field Programmable Gate Array (FPGA) based processor. The simulation results are validated using the experimental results.