Development of an Array Tracking Controller Using a Single Chip Computer

摘要

This paper reviews the design and performance analysis of a reliable, low-cost ($150) photovoltaic array sun tracking controller which is under development at Sandia National Laboratories. The system uses a Motorola single-chip computer to perform all tracking functions, and reliable, low-cost Hall-effect sensors to count motor turns. The EEPROM memory on the computer chip and a clock/calendar chip with battery backup are used to make the system recoverable from power failures. An important feature of the system is its ability to operate autonomously, independent of a master controller and without requiring operator alignment. The paper discusses the details of the self-alignment procedure which uses periodic measurements of the array current to determine the array tilt and clock errors. (ERA citation 12:040700)