Analysis of Two-Axis Sun Tracking System

Abstract

In this study, a two-axis sun tracking system with an open loop computer control is analyzed. For this purpose, a gyroscope-like prototype with two degrees of freedom is designed. In order to control the prototype and track the sun all along the day, computer software based on astronomical equations is developed. Beside the software, an electronic circuit ensuring communication layer in between computer and the prototype is designed and manufactured.Software determining the sun position precisely and controlling the prototype is developed utilizing a Visual Basic compiler on a Pentium IV 1600 MHz computer. Input-output signals in between the computer and the electronic circuit is managed through the parallel port (LPT) of the computer. Control of the prototype motors are performed by amplifying the sun position-related computer signals on the electronic circuitry.Critical components of three-dimensional system model created in Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE) software are analyzed from statical aspect. In addition, mathematical model of the system and its stability analysis is generated in Matlab/Simulink software.Last, a fixed-type photovoltaic cell and a two-axis sun tracking photovoltaic cell satisfying a particular tracking sensitivity are theoretically analyzed and compared. A two-axis sun tracking system working to fulfill a specific tracking sensitivity is theoretically seen to provide about 40 % higher energy gain when compared to a fixed system under extraterrestrial solar radiation.