A Study on the Development of Two Axes Sun Tracking System for the Parabolic Dish Concentrator

Parabolic Dish형 태양열 집열기를 위한 2축 태양추적장치의 개발에 관한 연구

The work presented here is a design and development of sun tracking system for the parabolic dish concentrator. Parabolic dish concentrator is mounted on azimuth and elevation tracking mechanism, and controlled to track the sun with computed and measured sun positions. Sun tracking mechanism is composed of 1/30000 speed reducer(3 stages) and 400W AC servomotor for each axis. The nominal tracking speed of each axis is ${\pm}0.6^{\circ}/sec$ and the system has a driving range of $340^{\circ}$ in azimuth and of $135^{\circ}$ in elevation. Sun tracking control system consists of sun sensor, wind speed and direction measurement system, AC servomotor position control system and personal computer as a master controller. Sun sensor detects the sun located within ${\pm}50^{\circ}$ measured from the sun sensor normal direction. Computer computes the sun position, sunrise and sunset times and controls the orientation of parabolic dish concentrator through the AC servomotor position control system. It also makes a decision of whether the system should follow the sun or not based on the information collected from sun sensor and wind speed and direction measurement system. The sun tracking system developed in this work is implemented for the experimental work and shows a good sun tracking performance.