Sistemas fotovoltaicos de bombeamento de água baseados em conversores de frequência convencionais

Abstract

Photovoltaic water pumping systems are typically sold as closed solutions using specific components at a high price. Despite this, it is possible to develop solutions based on standard equipment, which are widely available, reliable and inexpensive. These solutions use standard frequency converters and AC pumps. Although it is possible to connect a high voltage photovoltaic string directly to the standard frequency converter, the string becomes oversized for low power applications, which include pumps of up to a few hundred watts. This work develops and validates new approaches for low power applications using only up to 4 photovoltaic modules. The first approach uses up to 4 modules, charge controller, battery, battery inverter, frequency converter and single-phase AC pump, which has been tested with various configurations, technologies and battery voltage levels (12, 24 and 48V). The second approach uses a boost converter designed to replace the charge controller, battery and battery inverter. In addition, this work also carried out an impact analysis of photovoltaic pumping in certain regions susceptible to lack of potable water in Brazil, all with the aid of public data and GIS tools. These two approaches have been successfully validated. The results show that it is possible to build a system based on a standard frequency converter, proving its value for small companies to develop their own cost-effective solutions with modularity and worldwide equipment availability. This work was developed in cooperation with Valled Soluções Energéticas and CHL Engenharia e Distribuição, small companies in Portugal that have experience with photovoltaic lighting and photovoltaic water pumping.