Application of a frequency inverter in irrigated perimeters: A case study for irrigation automation

Abstract

The wide variation in water demand and pressure means that most irrigated perimeter pumping systems are oversized. The objective of this study was to control a pressurized irrigation system using a frequency inverter, aiming at automation and energy savings in irrigated perimeters. First, a prototype was assembled using drawer valves to simulate head losses in the system. Second, a frequency inverter was used to control the speed of the rotation of the motor pump, improving its performance. Finally, a microcontroller was used to manage the number of plots under irrigation in the perimeter. The frequency inverter reduced the consumed power by 40, 30 and 19% and the electric power consumption per hour by 46, 38 and 23% for one, two and three plots under irrigation, respectively. The use of the inverter frequency led to a reduction in operating points for all irrigation plot scenarios evaluated. The use of the frequency inverter is justified when the full power of the pump is not always required and adjustment of the rotation speed is necessary. In addition, the proposed automation system proved to be efficient in managing the rotation control of the frequency inverter.