Optimisation of photovoltaic water pumps coupled with an interfacing pulse width modulated DC/AC inverter power conditioning device

A proper matching of electromechanical loads to a PV array is a great problem in many PV power systems. This is mainly related to the nonlinear solar irradiance and cell temperature-dependent voltage and current characteristic of the PV array generator. A simple nonlinear optimisation technique is used to solve the load matching problem of a PV water pumping system. A number of case studies (at best and worst month solar radiation situations) are presented based on the power consumption of the load. Results show that, an optimum matching factor of 0.74 and 0.55 (at best and worst month respectively) can be achieved using 1.76 kWp M55 type PV array and M402/SP5A-7 type motor/pump with SA1500 DC/AC inverter interfacing device in this works field study area. It is possible to achieve a higher load matching factor by selecting carefully the proper size of the array and the motor/pump.