A COMPARATIVE STUDY ON PERFORMANCE IMPROVEMENT OF A PHOTOVOLTAIC PUMPING SYSTEM

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 optimisation problem consists in maximising the daily pumped water quantity via the optimisation of the motor efficiency for any operating point, this has led to an optimum ‘ v-f ’ relationship useful in controlling the motor. The voltage source PWM inverter feeding the motor is controlled via the ‘Harmonic Elimination’or the ‘Harmonic Minimisation’ strategies. The effectiveness of the proposed algorithm is described by simulation where the obtained results show that the ‘Harmonic Minimisation’ technic allows at the same time a notable improvement of the plant and an optimum matching of the system to the PV generator. This leads to a simplicity of impementation, bearing in mind that the MPPT circuit is omited.