Pyramidal Sun Sensor: A Novel Sun Tracking System Solution for Single Axis Parabolic Trough Collector

Abstract

A sun tracking system incorporated into a parabolic trough collector for precise control is presented in this study. The collector’s rotation axis is aligned with the east-west direction. With a concentration ratio of 160 and a narrow acceptance angle of 2 deg, achieving accurate tracking control is crucial for maximizing performance. To accomplish this, two established tracking configurations, namely open-loop and closed-loop, are utilized. The open-loop control utilizes a sun position algorithm. At the same time, the closed-loop system incorporates a sun sensor designed with light-dependent resistors. The proposed embedded system was verified using an experimental prototype. The experimental prototype was developed using the AVR ATMega32, a low-cost microcontroller. It was tested for tracking errors in both configurations. The outcome of the experimental prototype is presented in this work. The tracking controller provides a convenient solution to low-cost sun tracking using simple light-dependent resistors connected in a bridge configuration. The tracker’s accuracy can be conveniently controlled using the sun sensor’s threshold voltage, thus making it adaptable to different working environments.