A self-aligning photovoltaic array tracking controller

The author describes the design features of a low-cost tracking controller for photovoltaic concentrator arrays which is designed for use in commercial fields. The system hardware and software are described, and the system development status, performance, and cost are discussed. The system achieves a powerful yet flexible control capability by using a commercially-available microcontroller. It uses an open-loop control algorithm that eliminates the need for a sun sensor, and it performs its own initial alignment using the array output, minimizing installation manpower. The system is expected to achieve a tracking accuracy of better than +or-0.15 degrees on an array with little backlash.