Improving the performance of PV based water pumping system for fluctuations in irradiance

In real time field conditions, situation arises when sudden and a large change in insolation level occurs. Such frequent fluctuations in irradiation level, affects adversely the performance of Photovoltaic (PV) based water pumping system. Sudden large fall in insolation leads to generation of PV power which is insufficient for operation of motor-pump system and such frequent variations in insolation level results in unstable operation of PV based water pumping system. In this paper a standalone PV based water pumping system with super-capacitor (SC) as energy storage device is proposed. SC supports the operation of PV water pumping system in case of insolation fluctuations thus ensures stable operation of system. Proposed system is simulated in MATLAB/SIMULINK environment to verify its performance. Results show that in the designed system induction motor-pump system is able to work at constant speed, frequency despite of sudden large change in insolation.