Design and Analysis of Low-Cost and Efficient SEPIC Converter for Affordable Solar Water Pump in Ethiopia

Abstract

Abstract. Smallholder farms provide a significant share of the world's food supply. Smallholder farmers can cultivate crops more consistently throughout the year when using solar water pumps, which offer a dependable source of irrigation. However, the upfront capital cost and efficiency are major barriers to widespread adoption. This paper aimed to design a cost-effective and efficient DC-DC converter for small-scale irrigation farming in the Dangishta, Amhara region of Ethiopia, focusing on a direct solar water pump system using a SEPIC-based DC-DC converter. The system directly supplies power to a 100 W/24 V brushless DC pump, with a 120 W/24 V/5 A optimized SEPIC converter. A PLECS simulation was conducted to understand the converter's operation. The prototype design considered enhanced power handling capabilities using the paralleling method. The power switches are controlled by a digital circuit based on the RP2040 microcontroller, which generates PWM signals with a fixed duty cycle at 100 kHz. The average material cost of the converter was significantly minimized to approximately $15. Experimental tests showed an efficiency of 93.5% and an average temperature of 31°C, making it a promising solution for sustainable agriculture in resource-constrained environments.Keywords— Smallholder farms, Low-cost, SEPIC converter, Solar water pump, PLECS

Performance Evaluation of Solar Water Pumping System for Small-Scale Irrigation in Ethiopia

“…Range and accuracy of used measurement devices are declared and illustrated in the table I. The following formula is used to convert the measured pressure to head [32]:…”