Solar radiation and ambient temperature effects on the performances of a PV pumping system

This paper presents the influence of the solar radiation and ambient temperature variation on the performance of a stand alone photovoltaic pumping system which composed of a PV generator, DC-DC adaptor, DC-AC inverter and an immersed group motor-pump. Those performances such PV efficiency, inverter efficiency and flow rate are improved by a judicious control implanted on the converters. The maximal power point tracking (MPPT) control allows the extraction of the maximum output power delivered by the PV generator. However the inverter insures a pulse width modulation (PWM) control of the asynchronous motor and a sine wave form of output signals. We proceed to modelling the PV pumping system with power electronic converters allowing respectively optimal operating point tracking and power conversion under the appropriate command. From the obtained simulation results, under Matlab/Simulink environment, we will discuss how the ambient temperature and the solar radiation influence the performance of the PV plants. The experimental results of the PV pumping system installed in Tunisia (2.1 kWc) verify the validity of the model and the proposed controller.