Optimized solar water pumping system based on an induction motor driving a centrifugal pump

This paper suggests how an optimal operation of a photovoltaic pumping system based on an induction motor driving a centrifugal pump can be realized. The optimization problem consists in maximizing the daily pumped water quantity via the optimization of the motor efficiency for every operation point, which has led to an optimum 'v-f' relationship useful in controlling the motor. This is reached via the control of a natural PWM VS inverter feeding the motor. The effectiveness of the proposed algorithm is described by simulation and the obtained results are compared to those of a system working with a constant air gap flux. The obtained results allow the improvement of the daily pumped water quantity and the pump efficiency. In addition, the influence of changing array temperature is also discussed.