Water pumping for elevated storage using PV doubly-fed induction motor drive

In remote locations with rich solar insolation, simple and effective nano-gird schemes for day-hours feeding of the important pumping loads and auxiliary ac loads are highly desired. In this paper, a pump drive based on a PV doubly-fed induction motor is introduced. The desired operational features of such nano-grid such as unity power factor of the pump drive, stable supply of auxiliary ac load, and flexible distribution of power between pumping and ac auxiliary load as well as maximum power point tracking could be all realised using a partially rated rotor side PWM inverter along with an off-the-shelf full-rating standard inverter. The paper explains the design of the different necessary control loops such as the MPPT loop, the dc-link loops and the rotor current loops. The dynamic performance of the system is tested under varying insolation and auxiliary ac load conditions.