Research On Application Of On-load Capacity Regulation Distribution Transformer In Distribution Network

At present,energy conservation and emission reduction is the development trend of the world economy.Transformer is widely used in power grid,and its installed capacity is quite large.Although the efficiency has been higher with the progress of technology,the total loss is still large,and the loss of distribution transformer accounts for about 30%-40%of the total loss of power grid.In view of this problem,the application of on load capacity regulating transformer in distribution network is studied in this thesis,especially in rural areas,business centers and other areas with obvious peak valley phenomenon,in order to effectively reduce the transformer loss,reduce the loss of 10kV public lines,and improve the economic benefits of power grid enterprises.In Tongshan District of Xuzhou City,two pilot projects,Chengtou village of Zhangji town and pedestrian street of Normal University,are selected.Firstly,the energy-saving and capacity regulation mechanism of distribution transformer is analyzed.This thesis analyzes two basic methods of regulating capacity transformer,compares their advantages and disadvantages,and finally selects star angle regulating capacity method;analyzes the principle of energy saving and loss reduction of on load regulating capacity distribution transformer and the best economic operation point,which lays the foundation for selecting the capacity of on load regulating capacity distribution transformer according to the pilot load curve.On this basis,according to the pilot load curve and the future pilot power consumption forecast,the capacity of on load capacity regulating distribution transformer is determined to be 630(200)kVA.Secondly,the capacity regulating switch of on load capacity regulating distribution transformer is studied,and the type of capacity regulating switch is selected based on the analysis.This thesis compares the principle,performance,advantages and disadvantages of hand operated mechanical on load capacity regulating switch,mechanical on load capacity regulating switch,power electronic on load capacity regulating switch and composite on load capacity regulating switch,and selects the mechanical on load capacity regulating switch model of sytx-630(200)/(10kV)in combination with market product maturity and enterprise standard of State Grid on load capacity regulating switch.Next,the control system of on load adjustable capacity distribution transformer is studied,and the composition,function modules and operation strategy of the control system are analyzed.In view of the limitations of the existing operation strategy,this thesis puts forward the operation strategy research based on big data.Although it can not be realized due to objective reasons,it provides a direction of great reference value for the improvement of the control system in the future.On the basis of comparing the existing operation strategies,the economic operation strategy based on power load forecasting is selected,and the neural network algorithm is used to learn and forecast the pilot load,which has high prediction accuracy and good effect The overall design of the controller is carried out,focusing on the internal structure design,monitoring,acquisition and communication circuit design of the controller.The linkage function of the controller acting on the transformer capacity regulating switch is summarized,so as to meet the requirements of subsequent device selection.Finally,based on theoretical analysis,market product research and relevant standards of State Grid,the control system produced by Beijing dianyan Huayuan Power Technology Co.,Ltd.is selected.The pedestrian street of Normal University and Chengtou village of Zhangji town in Tongshan New District of Xuzhou City are selected as the transformation pilot,and the advantages of on load capacity regulating distribution transformer are analyzed from the perspective of economic and social benefits.According to the calculation results,a single distribution transformer can achieve an annual economic benefit of no less than 80000 yuan and reduce carbon dioxide emissions by 3000 tons.There are 27 figures,2 tables and 81 references.