Design of a Low Power Off-Grid Photovoltaic Water Pumping System for Rural Areas

A simple and low power standalone photovoltaic (PV) water pumping system with conventional centrifugal pump is presented here. The system uses a DC-DC boost converter which extract the maximum power from the solar array and a Sine Pulse Width Modulation (SPWM) technique based Voltage Source Inverter (VSI) for DC-AC conversion. The DC link voltage is controlled by varying pump speed to match the available solar power to pump power. The proposed control scheme requires no additional current and speed sensor. The simulation is performed in MATLAB/SIMULINK under different radiation condition. The simulation results show that the pump can run under low radiation and can fill up a 1000 liter tank within the average sun hours.