SPV Water Pumping system using Induction Motor Drive For Stand-Alone Application With Minimum Sensors

This paper introduces an economical Solar Photovoltaic (SPV) water pumping system using induction motor drive (IMD) for stand-alone application like water irrigation in rural area. This system consists of two stages of power conversion. In thel firstl stage, a DC-DCl Boostl converterl is employedl to extract the maximum power from SPV array and the second stage involves voltage source inverter (VSI) for the conversion of DC bus voltage into AC to drive the induction motor (IM). A scalar volt/Hertz control method is used to control the speed of IM. It controls the speed of motor such that the DC bus voltage is retained constantly. This regulation reduces the motor losses by decreasing the motor current at high value of voltage for the same power rating. This system eliminates the need for speed sensors and stator current sensor of the motor. The reference speed for scalar volt/hertz control method is generated by the proposed control scheme. This control scheme also provides a feed-forward speed to improve the dynamic response of the system. A Perturb and Observe (P&O) based maximum power tracking (MPPT) algorithm is used to control the duty ratio of Boost converter. The proposed system is designed and its performance is simulated using MATLAB/ Simulink software.