Altazimuth sun tracking systems

Abstract

The primary purpose of an altazimuth sun tracking system is of course, to keep the collector pointed in the optimum direction so as to minimize the incidence angle and keep the solar image centered on the absorber as the sun moves across the sky. There are two commonly discussed methods of tracking control. These are the active or closed-loop control system and the passive or open-loop control system.' Systems of the active or closed-loop type "actively" make some measurement of where the collector is end then, if alignment is not proper, activate devices that can change the orientation of the collector. Unless the collectors are grouped together with some mechanical linkage, individual active control systems must be placed on each collector. The sensing devices that make the system an active one are usually light sensitive detectors. Ideally these sensors should be placed on the receivers to ensures that the receivers are always at the focal point [...]