Simulation of sun tracking system for point focus fresnel collector

Abstract

This work presents simulation of a sun tracking system that was developed for a Point Focus Fresnel Collector (PFFC) installed at King Saud University. The tracker is dual axis with a concentration ratio of 160 and a small acceptance angle of 2 degrees, hence a precise tracking control is required. Two control schemes were developed and tested, the open loop and closed loop. A sun position algorithm was used for open loop control whereas a sun sensor was used for closed loop control. The control system were simulated using Matlab/Simulink. It was found that open loop tracking is simpler to implement and consumes less power but is also less accurate and tracking error accumulates over time. On the other hand, closed loop control is more complicated to implement, consumes more power is much more accurate than open loop control. So, it is recommended to use the closed loop controller for PFFC system. The individual components of the control system were modelled using generic Simulink models. The complete model was operated in both open loop and closed loop configurations. The results of the models were analysed to estimate the operating limits of the tracker.