An experimental realization of improved grid integrated multilevel inverter based PV systems with MPPT

Abstract

This research work explains a sliding mode controller-based multilevel inverter for grid integrated photovoltaic power structure. A gravitational search algorithm based on maximum power point tracking has also been discussed for optimal photovoltaic power achievement. Moreover, a two-stage cascaded interleaved boost converter has been employed, which provides minimised voltage/current ripple, higher current/power density, better efficacy, faster response, and reduced electromagnetic interference as major benefits. The multilevel inverter's proposed constant frequency-based sliding mode controller provides better transient responses, high photovoltaic power tracking, and good robust behaviour under changing operating conditions. The proposed sliding mode controller has a fixed frequency operation and has low reactivity to parameter divergence. The proposed multilevel diode clamped inverter for grid integrated photovoltaic system provides a reduced number of components and a power rating. The gravitational search algorithm-based swarm technique as a maximum power point tracking provides high convergence velocity, better accuracy, and good local search capability. The experimentation was carried out to implement control algorithms using the dSPACE platform. The designed multilevel inverter system with proposed control provides average 89.2% inverter efficiency under variation of sun insolations.