Dunqiu Substation Entirestation Lose Voltage Accident Emergency Treatment Plan Of Research

Substation is a power facility that transforms voltage, receives and distributes electrical energy and controls the flow and adjustment of electricity. It is an important part of power system. The 220kV Dunqiu Substation is located in the north of Puyang City. Its voltage loss may cause the voltage loss of its four affiliated 110 kV substations and a load reduction of 200MW, resulting in the serious consequence of large-scale power failure in Qingfeng County and Nanle County. For a faster and more reliable solution in case of whole-station voltage loss, it would be an effective method to develop a preplan and carry out emergency drills accordingly.The contents of this dissertation are:A thorough study of Dunqiu Substation's location in Puyang power grid, normal operation analysis, low-voltage configuration, DC system configuration and protection configuration.A comprehensive calculation for the 220kV and 110kV single-phase grounding fault, two-phase grounding fault, two-phase fault and three-phase grounding fault, and 10 kV two-phase fault and three-phase fault both before and after the reactor at Dunqiu Substation.A detailed analysis of the whole-station voltage loss at Dunqiu Substation. As the substation has two 220kV lines (Cang-Dun LineⅠand Cang-Dun LineⅡ) and two transformers connected to 220kV double bus and on the 110kV side are all feeder lines, the possibility of whole-station voltage loss is low in normal circumstances. Whole station voltage loss can be caused by:(1) Large-scale power failure, including the 220kV voltage loss of Changjie Substation.(2) Fault within the substation, such as Cang-Dun Line I and Cang-Dun Line II fault.These two causes are studied respectively in terms of situation analysis, accident premonitions and steps of accident handling, followed by a case study which presents the entire process of handling a whole-station voltage loss caused by the fault between the 220kV Dun 220 switch and Dun 220 CT. The preplan for the whole-station voltage loss at Dunqiu Substation, which is developed by the author, has been comprehensively applied at Dunqiu Substation. Through emergency drills carried out every quarter, the operators'abilities of accident analysis and handling and transfer switching have remarkably improved, which is also thought highly of by the leaders. What's more, operators of Dunqiu Substation have won the group championship for several times in technological competitions of accident-handling and transfer switching organised by the company.