Performance study of a standalone direct pumping photovoltaic system used for drip irrigation

Abstract

This paper aims to study performances of a standalone photovoltaic pumping system confronted to actual behaviour of incident irradiance. The system is based on a photovoltaic generator, a MPPT/ DC-DC converter, and a diaphragm DC motor pump connected to calibrated ( Flow versus Pressure) orifices, simulating small drip irrigation network, mounted in parallel scheme to vary the pump operating point according to timely varied irradiance. The result showed  that daily trend of solar irradiance influence considerably operating behaviour of the pump, consequently the performance of the standalone PV system is affected as there is inadequation between charges of the PV generator and the DC pump.  The hydraulic effeciency trends showed a dispersion and varying performances according to irradiance change and to hydraulic system unstability. A method of gouverning hydraulic performance is proposed to improve the system efficiency and pressure stability as requirements for water distribution uniformity in drip irrigation network supplied by a standalone PV pumping system..