Two-stage stand alone photovoltaic system for water pumping system

This paper presents a two-stage photovoltaic system based on a three-phase induction machine for water pumping purposes. The system is designed to work in isolated mode as it is intended to use in remote areas. A control algorithm is proposed for a DC-link voltage regulation and boost current control in a cascaded loop. The induction machine has a speed control based on V/F scalar method. Experimental results demonstrate the behavior of the systems for different levels of irradiance, temperature and load.

I. INTRODUCTION

The photovoltaic (PV) power systems has a wide range of applications, one of each is the use of solar energy to power water pumping systems. As a motivation for the use of this system, we can look to the small farmers at Brazil. Although responsible for 70% of the food consumed in the country, this type of agriculture generally has little access to the electric power distribution [1]. They need to pump water for irrigation, to livestock and for domestic use. These farmers need a system that can meet their needs of energy and it is low cost. A system that is powered by renewable energy sources (solar and wind) seems suitable for this application. This system has an advantage of being reliable, with low maintenance and long lifespan.