The Study On Feasibility And Safety Of The Hot-line Work On The Same Corridor Line Of UHV And EHV

In recent years,with the development of power grid and the wide use of transmission line of UHV and EHV,which not only greatly improve the transmission capacity,and realize the large power,long-distance transmission,and remote power system interconnection,but also save the line corridor area,and improve the utilization rate of the same corridor line.It achieves a comprehensively economic and social benefits.In order to improve the economic efficiency and reduce the unnecessary power cut,the hot-line work on the transmission line of UHV and EHV is used widely.Therefore,the research on the hot-live operation of UHV and EHV has become a key point of the maintenance of power network.At present,the hot-line operation on the independent corridor line of UHV and EHV has been carried out,but the feasibility and safety are still in the study.In combination with the present situation of the Huzhou area of EHV and UHV "four in one" same corridor line with multi-circuit,this paper introduces the operating characteristics and parameters of EHV and UHV transmission lines firstly.Then,a multi-circuit DC line coupling model is established by PSCAD.After that,this paper sets up four-circuit UHV AC / DC coupling model and calculates the maximum value of induced over-voltage of the four-circuit AC / DC line in fault condition.With those data,the comparison with the existing insulation coordination of live work can be achieved,which verifies the feasibility of live work with multi-circuit corridor.To obtain the electric field intensity of the typical position and calculate discharge energy,the electric field simulation of the four-circuit same corridor line is carried out by computer software.The results are compared with the electric field intensity of the single circuit line with the voltage level.Therefore,the safety of the hot-live operation of the same corridor with multi-circuit is described.The aim of this paper is studying feasibility and safety of the hot-line work on the same corridor line of UHV and EHV.It provides theoretical data and reference for the future work.