Research On Cluster Control System Of Seasonally Adjustable Leveling Uniaxial Photovoltaic Bracket

In the photovoltaic power generation system,the photovoltaic bracket plays a very important role.At present,the seasonally adjustable photovoltaic bracket has become a form of bracket with a large scale of construction at present due to its advantages of simple structure,good stability,low manufacturing cost,and small residual rotation loss in high latitudes.Its main features are the east-west arrangement of the main axis of rotation and the operating mode of manual adjustment 4 times a year.However,with the continuous expansion of the scale of photovoltaic power plants in recent years,the operation difficulty and manual operation and maintenance costs of seasonally adjustable photovoltaic brackets are rising.And the existing operating mode of the bracket is not always at the optimal power generation inclination,and a part of the power generation will be lost every day.Therefore,in order to realize the low-cost automation of seasonally adjustable brackets,this paper studies the cluster control system of seasonally adjustable single-axis photovoltaic brackets,and the specific work is as follows:Firstly,by analyzing the adjustment mode of the existing seasonally adjustable photovoltaic bracket,the slow operation law of the whole year is pointed out,the solar operation law under the horizon coordinate system is analyzed,and the tracking method of apparent solar motion trajectory is finally determined to be used to track the sun by comparing the currently commonly used solar tracking scheme.In order to reduce costs,the seasonally adjustable bracket control system of a single photovoltaic subarray is designed as a cluster control system composed of a high-complexity main control system and many bracket controllers.Secondly,in order to improve the power generation of the system,two different tracking modes of seasonal tracking and continuous tracking are designed in the main control system,and PVsyst software is used to model and analyze the results of the seasonally adjustable photovoltaic system in different tracking modes.In order to maximize the daily solar radiation received by the system in the seasonal tracking mode,an optimal daily tracking angle algorithm is designed in this mode.Aiming at the shadow occlusion problem of front and rear PV modules in the period when the height angle of the sun is small in winter under continuous tracking mode,a winter anti-shadowing algorithm is proposed,which realizes the automatic anti-shadow control of the front and rear PV brackets and can also improve the local land utilization rate.Thirdly,according to the overall scheme of the system hardware,the hardware schematic diagram of the self-powered system composed of the main control system,the bracket controller and the small photovoltaic panel and super capacitor are respectively designed.In terms of software design,the main control system,bracket controller and all communication task programs in the system are designed in detail to improve the stability of the system.In the last part,the upper computer software based on MCGS platform was designed,the engineering application debugging of the cluster control system in this paper was completed,and the actual operation data of the site was analyzed.The results show that the control system can realize the group control of all photovoltaic brackets and achieve a tracking accuracy of 0.1 degrees.The self-powered system can stably supply energy to the drive unit and the bracket controller,and improve the overall power generation of the system while realizing the low-cost automation of the seasonally adjustable bracket.