Enhanced power quality in single-phase PV-integrated grids using a state-space RLS adaptive filter with multilevel inverter

This paper proposes a novel approach to enhance the control algorithm for a single‑phase grid connected unit by integrating a state space recursive least squares adaptive filter with a reduced switch count multilevel inverter, consisting of a photovoltaic array (PV array) unit integration to reduce numerous power quality problems. Modelling of five level reduced switch count multilevel inverter in combination with the proposed state space recursive least squares adaptive filter accomplished in Matlab/Simulink. The proposed system has undergone comprehensive testing and validation utilising the advanced OPAL-RT real-time data simulation platform to ensure robust performance evaluation and accurate results under dynamic conditions. Based on the simulation models and experiments, it is noticeable that the proposed system functions correctly under changes in loads. Furthermore, the proposed method is evaluated against several conventional adaptive methods to identify its advantages. The total harmonic distortion (THD) values for both supply voltages and currents comply with IEEE-519 standards. The limitations of conventional two-level inverters, including higher harmonic distortion, restricted voltage levels, and reduced power quality, underscore the advantages of multilevel inverter systems.