A Low Power Photovoltaic Water Pumping System based on a DC-DC Step-up Converter and Standard Frequency Converters

Photovoltaic Water Pumping Systems (PVWPS) are a solution to supply water to populations living in arid and remote regions. One problem is that these systems are usually sold as closed kits and with solar energy dedicated equipment. This situation makes it difficult to replace damaged equipment for others that would be available on the market. Also, solar dedicated equipment are more expensive than the general-purpose ones. Another issue is the oversizing of the photovoltaic string in terms of power, when installing low power PVWPS that employ conventional AC water pumps. The oversizing occurs in order to achieve the voltage requirements of these pumps (rated with less than 1kW). In the interest of solving these problems, this work proposes a solution for a low power PVWPS. The proposed system employs a maximum of 4 photovoltaic modules; a DC-DC step-up converter; a standard frequency converter and an 1HP AC water pump. It was designed and tested a 750W DC-DC step-up converter with a static gain of 3.44 for composing the proposed solution. The whole set of the low power PVWPS was tested in a laboratory environment and showed a full day of operation. The present work was held in cooperation with the company VALLED.