The Solar Tracker – A Control System and a Frame Construction

Abstract

Ecology is among the most important challenges facing humankind in the 21st century. The depletion of energy sources compels us to search for alternative methods of electricity generation. One of the most common methods is to use photovoltaic panels that utilize solar energy for generating electric current. Photovoltaic panels should be positioned perpendicularly to the solar radiation incidence direction. Their efficiency is then the highest. Special frames are constructed to support the photovoltaic panel and allow it to rotate. A frame structure developed at the Institute of Machines Technology of the Czestochowa University of Technology is equipped with an advanced system that tracks the apparent motion of the sun. For its construction, steel sections and a micro-processor control system were used. The control program uses a hybrid algorithm that counts the sun position according to the date and time and reads out the indications of a differential sensor built from photoresistors. The position of the photovoltaic panel relative to the sun is corrected with stepper motors with N-encoders allowing rotation in the perpendicular axis parallel to do the earth surface. The developed frame structure and the control system are versatile and enable commercial photovoltaic panels to be mounted. They provide an alternative to expensive solutions offered by installing companies and are possible to be used in the conditions of a typical household.