Design of closed-loop control for Solar PV based Multi-Level Inverter

Abstract

Photovoltaic (PV) based multilevel inverters (MLI) have emerged as one of the best alternatives for grid/standalone applications. MLIs offer high range power handling capability with low current and voltage distortion and lesser switching losses as compare to the traditional two-level inverter. Major challenges with generally used multilevel inverter topologies relates to capacitor voltage variation, modulation techniques, and control. The major center of attention of research in this paper is to build up sophisticated modulation and voltage balancing methods for multilevel inverter topologies, competent to reach capacitor voltage parameter and to decrease power switching losses of the inverters. The present paper focuses on closed-loop control of multilevel flying capacitor inverter (FCI). In FCI, the phase shift (PS) based pulse width modulation method is designed and investigated. The closed-loop controller is designed with input voltage control of MLI, whose source is solar PV based Boost converter. Reported simulation results prove the superiority of the closed loop control in maintaining the desired output voltage for various reference values.