Performance improvement of a PV-powered induction-motor-driven water pumping system

摘要

This paper presents a modified control strategy to improve the performance of a 3-phase induction motor drive system fed by a standalone PV power source. The main functions of the proposed control strategy are: 1) ensuring successful motor starting, 2) matching the on-site induction-motor pumping load with the available PV power, and 3) forcing the PV system to operate at the maximum power point. The maximum power point tracking (MPPT) is based on perturb and observe (P&O) algorithm. The system consists of a DC/DC boost converter, DC link capacitor, 3-phase inverter, 3-phase induction motor and PV power panels. The PV panel structure is designed to maintain the system operating point at the PV maximum output power at variable solar irradiations. Simulation results demonstrate the operation of the unified system with and without controller under constant and variable solar irradiations. The main control objective is to run system as close as possible to the maximum power point operation under constant and variable solar irradiations. Simulation results using boost converter along with the P&O algorithm show an accurate MPPT at rapid-change of solar radiation and the ability of the system to approach for MPP.