Research And Implementation Of 220kV Yancheng Substation Capacity Increased Reconstruction Project

Electric energy is one of the main forms of current energy consumption in the world,as a special commodity,it cannot be stored in large quantity but to be generated,transported,sold and consumed at the same time.Substation,as an important part of power grid,is of great significance to coordinate its construction schedule,optimize its design scheme and transform its aging project.The implementation of correct and reasonable substation design can maximally save national infrastructure investment,promote the healthy development of national economy and improve the economic and social benefit of other industries,its importance is therefore self-evident.Phase I project of 220 kV Yancheng Substation was put into operation in May 1982,while its phase II project was put into operation in January 1986,with total operation time more than 37 years,but in view of the historical conditions at that time,the construction standard of this substation is low.However,along with the fast economic development and acceleration of power grid construction in northern urban area of Yancheng,the contradiction between Yancheng Substation as well as its inlet and outlet cables and the power grid development and the surrounding environments increasingly stands out.For one hand,it has potential safety hazards in construction and equipment,as the interval of 220 kV and 110 kV outlet cables in the substation has been used up,the main equipment is quite old,the earthquake resistance and firmness of its original buildings and concrete frames have greatly reduced due to long-term weathering corrosion,and it has some electrical defects such as heating of sluice,grounding of direct current,corrosion of electromagnetic lock,old cables,and corrosion of wiring in terminal box;for the other hand,two main transformers run with full load for long time,which results in difficult grid arrangement.The modification of Yancheng Substation is a systematic project,which shall take all aspects into consideration at the design stage.In this paper,the design scheme of 220 kV Yancheng Substation is studied and demonstrated from five aspects of 220 kV inlet system scheme,primary electric design,short circuit current calculation and equipment selection,general electric arrangement and types of distribution apparatus,and secondary system design.Meanwhile,with the combination of actual conditions in the field,the outdoor high-voltage distribution apparatus of the substation is transformed into GIS equipment by adequate use of the original high-voltage equipment area in the substation,by use of line-to-group wiring and through several procedures so as to complete the modification project without affecting the external power supply.After the modification,the distribution capacity of the substation will be improved,the interval of inlet and outlet cables will be increased,the main wiring will be simplified,old high-voltage distribution apparatus will be eliminated,and the secondary equipment will be realized intellectualized modification.The aging of Yancheng Substation will be solved at one stroke to improve the power supply capacity and reliability of the power grid in the district.The modification scheme and practice of 220 kV Yancheng Substation provides a good template to capacity-increase modification of other old substations in the city center.The necessity,principles,implementation procedures and effects of 220 kV substation modification of old high-voltage distribution apparatus are put forward through generalization and summarization,which can be used as reference for similar practice.