Investigating Impact of Boost Converter on Efficient MPPT Based Solar PV Array for MicroGrid System

Abstract

This study presents an optimized design of a Maximum Power Point Tracking (MPPT)-based solar photovoltaic (PV) system, aimed at enhancing overall performance through refined MPPT control and boost converter optimization. The investigation focuses on the influence of boost converter operation and MPPT control signals on Total Harmonic Distortion (THD) at the inverter output. A detailed model is developed for a 100-kW PV array interfaced with a 25-kV grid via a DC-DC boost converter and a three-phase, three-level Voltage Source Converter (VSC). The MPPT functionality is implemented using the Incremental Conductance algorithm with an integral regTulator. Harmonic mitigation is addressed through a sequence of measures, including modelling of two independent PV arrays under varying irradiance and temperature conditions, application of the Perturb and Observe (P&O) algorithm for optimal power extraction, and the design of a modified boost converter topology with enhanced filtering. Comparative simulations demonstrate the effectiveness of the proposed system relative to conventional MPPT-boost converter configurations. Analysis shows that the initial system exhibits a THD of 44.83%. Introducing an RC shunt filter in the boost converter and reducing the sampling time lowers the THD to 3.08% at a 60 Hz fundamental frequency. Further optimization, achieved by reducing the sampling size and aligning the switching instant with the waveform, decreases THD to 0.43%. These results highlight the critical role of sampling strategies and filter integration in improving power quality, confirming the proposed approach as a significant advancement in the design of grid-connected solar PV systems.