SUN TRACKING CONTROLLER FOR MULTI-KW PHOTOVOLTAIC CONCENTRATOR SYSTEM.

Abstract

A description is given of a two-axis sun tracking controller designed to achieve low cost, high performance reliability, and operational flexibility for multi-KW to multihundred KW photovoltaic concentrator applications. The controller is based on an active sun sensing approach and allows an array assembly to track the sun within five arc-minutes. It has the capability to stow the array at night or during inclement weather conditions, communicate with an external computer, and provide autonomous operation and diagnostic monitoring. These functions along with the basic design goals were achieved by using a dedicated microprocessor. The prototype of the third generation sun tracker design has been designed, fabricated, and is now in the verification stage. It represents a significant improvement over the two earlier generations which were based on hard-wired logic. The sun tracking unit can be readily adapted for use on any application that requires sun pointing.