A Single Stage Photovoltaic Solar Pumping System based on the Three Phase Multilevel Inverter

Abstract

This paper presents a study of a single-stage DC-AC converter for a solar water pumping application. The topology was based on solar panels connected to a new structure of a three-phase multilevel inverter through DC-bus capacitors. The inverter offers simplicity, requires fewer components compared to conventional ones, and provides optimal voltage and current waveforms with reduced harmonics, eliminating the need for filters. The applied control technique aimed to stabilize the input DC-bus voltage, extract the maximum power using a simple MPPT algorithm, and enhance the efficiency of the water pump through scalar V/f control, regardless of weather changes. A simulation was conducted using the PSIM software, considering a variable daily climate scenario. The results obtained demonstrate the efficiency of the system in extracting energy with optimal torque and current for the pump compared to a classic design based on a three-phase H-bridge inverter.