Abstract

A new converter-inverter drive system for photo- voltaic (PV) water pumping without the use of chemical storage elements, such as batteries is proposed here. The converter is designed to drive a three-phase induction motor directly from PV energy. The use of a three-phase induction motor presents a better solution to the commercial dc motor water pumping system. The development is oriented to achieve a more efficient, reliable, maintenance-free, and cheaper solution than the standard ones that use dc motors or lowvoltage synchronous motors. The pro- posed system is based on a current-fed multi resonant converter also known as resonant two-inductor boost converter (TIBC) and a full-bridge three-phase voltage source inverter (VSI). The classic topology of the TIBC has features like high voltage gain and low input current ripple. Here the control methods of inverter like Sinusoidal Pulse Width Modulation (SPWM) and Third Harmonic Injection Pulse Width Modulation (THIPWM) are simulated and compared the performance of both. In this system, it is further improved with the use of a non-isolated recovery snubber along with a hysteresis controller and the use of a constant duty cycle control to improve its efficiency. To maximize the power output from PV, MPPT control is provided. The system is expected to have a high lifetime due to the inexistence of electrolytic capacitors, and the low cost of the converter. As a result, the system is a promising solution to be used in isolated locations and to deliver water to poor communities.