Performance of a self-aligning solar array tracking controller

Sandia´s advanced SolarTrak control system provides Sun tracking, night and emergency stow, communication, and manual drive control functions, for one and two-axis solar trackers in a low-cost, user-friendly package. The author describes the hardware design features and sophisticated control algorithms, such as a six-degree self-alignment routine and a self-adjusting motor actuation time, that enhance SolarTrak´s pointing accuracy and system reliability while at the same time reducing operation and maintenance requirements. Performance measurements taken on operating systems over the past year show that full-day pointing accuracies of better than ±0.1 have been achieved