Trajectory Design And Control For Dual-Axis Solar Tracker Of Photovoltaic Power Generation System

With the decrease of existing energy and the deterioration of ecologicalenvironment, the Photovoltaic (PV) power generation system has got moreand more attention by the whole world and its annual installed capacity isgrowing significantly. However, its development has been restricted by thecharacteristics of the low efficiency and the high cost. Therefore, the studyof improving the efficiency and reducing the costs has become a hotspot ofall countries. Aiming at different locations, different time and differentconstraints of dual-axis solar tracker, this paper focuses on the research of itstrajectory design and control. In this paper, a real-time model of PV array isestablished, and then through the analysis of environmental factors on theimpact of PV array, the tracking trajectory of dual-axis solar tracker isdesigned. Subsequently, the controllers are used to track the trajectory andachieve the purpose of improving the generation efficiency of the PV array.Firstly, on the basis of a single PV cell modeling, the relationships ofthe model and model parameters between the PV array and the PV cell areanalyzed. And then, a dynamic model of the PV array is established. Insteadof the empirical method, an iterative algorithm is used to solve theparameters by analyzing the existing modeling methods. Thereby theaccuracy of the model is improved. After that, the impact of environmental factors on the efficiency of the PV array is studied. Finally, the basis todesign the trajectory of the dual-axis solar tracker is obtained, which lay afoundation for the following research.Secondly, the trajectory is designed by combining with the impact ofenvironmental factors on the generation efficiency of the PV array and themethod to calculate the sun position. In the process of designing thetrajectories, the constraints of trackers are taken into account. Then the PIDcontrollers of the two servo system are designed so that the tracker can trackthe desired trajectories. This method is versatile and suitable for differentlocations, application time and the position constraint. Finally, somedifferent situations are set in the simulation to verify the above theory. Thesimulation results show that, the proposed method can effectively improvethe generating efficiency of the PV power generation system.Thirdly, the experimental results are studied by testing the30Kwphotovoltaic grid-connected generation system of our laboratory. The resultsshow that the method has good performance in improving the efficiency ofthe PV power system. In addition, in order to facilitate the manipulation ofthe operator, a monitoring system of the photovoltaic power generationsystem is designed, which can realize some basic functions like parametersetting, real-time and history curve observation, data recording, alarm,statements and so on.