Standalone Photovoltaic Water Pumping System using Induction Motor Drive

This paper presents a simple and efficient standalone photovoltaic (PV) water pumping system employing an induction motor drive. This system uses two power conversion stages linked by a DC-bus capacitor. The first is a DC-DC boost converter controlled by using a perturb-and-observe (P&O) maximum power point tracking (MPPT) technique; used to extract the available maximum power of the PV array. The second is a three-phase Pulse-Width Modulated Voltage Source Inverter (PWM-VSI) coupled to an induction motor for driving the centrifugal pump. This drive is controlled by the indirect field oriented control (FOC) which ensures high dynamic and static performances. The DC-bus voltage is regulated at a required level by using a proportional-integral (PI) controller. The reference speed is estimated from the affinity law and the DC-bus voltage control. The performances of the system are verified by digital simulation under Matlab/Simulink environment in steady-state and dynamic operating conditions.