Design Of Tracking And Control For Solar Parabolic Trough Thermal Power System

The system of sun tracking and control is in a wide range of application as the main method to improve the efficiency of radiation utilization about solar power system. The key technology of the Solar Parabolic Trough thermal power tracking control system is tracking of the movement of the sun on real-tine,and adapting to the chronic and intermittent property of the change about solar ray, and to the geography and weather changes to track accurately.Based on the analysis about solar tracking technology at home and abroad, using astronomical algorithms and relevant hardware configuration and the mechanical structure to get the position of sun accurately in the paper, the tracking accuracy of the system up to about0.1 degrees.Because of the influence of the earth rotation and revolution, the changes of sun zenith and azimuth reflect the sun movement rules,and the changes of sun declination angle and hour angle reflect the changes of sun zenith and azimuth.Using MATLAB simulation software to analysis and compare the accuracy of different calculation methods of sun declination angle and hour angle and use a higher precision calculation methods to ensure the accuracy of the tracking system.At last, based on the angle of zenith and azimuth to get the tracking angle.The experimental test platform is mainly composed of two parts, the parabolic through and the rotary table,the parabolic through is used to track the sun zenith and the rotary table is used to track the sun azimuth.In order to compare the effect of different collector tracking mode, using single-axis tracking mode and multi-axis tracking mode and other tracking modes.The core of hardware configuration control system is Schneider M241 PLC,the multi-mode speed control of Mitsubishi servo control system to control the angle of zenith,the PTO control mode of Schneider servo control system to control the angle ofazimuth.At the same time, using HMI to monitor system remotely real-time, the data transfer between PLC and HMI by Ethernet.