Loss models of photovoltaic water pumping systems

The paper presents loss models of photovoltaic (PV) DC and AC motor drive water pumping systems (WPS). The DC and AC motors are fed by power electronic converters with or without maximum power tracking. The models are developed with the objective of maximizing the conversion efficiency from the solar irradiation to the potential energy of water by taking into account the variations in the pumping head at a given insolation. The efficiency of the array, the pump and the motor are found to be the most critical parameters for the performance of the systems. In addition, matching of the drive system and the load with the insolation characteristic of the solar array is found to be critical, since maximum system efficiency occurs at a specific head, which varies as the insolation changes.