Research On Closed Loop Operation Of Distribution Network In Tongzhou,Beijing

Along with the network structure of the capital power system continue to improve, the power operation mode is flexible, service level power userssteadily. In order to improve the reliability of the capital distribution network,decrease network loss, improve the load capacity of network and use efficiency, the mutual supply ability is stronger, a ring network power supplynetwork structure is an inevitable trend, the distribution network can meet the needs of various operation modes.Distribution network closing loop operation when power is both sides split operation state, there is often because the loop switch sides bus or line voltage difference, make the circulation loop closing operation in productioncaused by excessive overcurrent protection maloperation. In order toprovide uninterrupted power supply for important customers, understandthe changes of power flow, avoid overload or accident is not necessary, the need for detailed analysis and calculation of the loop current, it is helpful for the operator operation mode for regional power network to make the appropriate adjustments, so as to ensure the interests of users, reduce the outage loss.In this paper, combined with the characteristics of the basic structure andoperation mode of distribution network, one one kinds of closed loop operation, closing loop operation advantages and potential risks. Thepower flow calculation method, calculation method of closed loop current,transient current calculation method, short-circuit current calculation method as the theoretical basis, select Beijing Tongzhou typical distributioncase analysis.With the Beijing Tongzhou District as the "capital of high-speed constructionDeputy Center", are especially important to enhance the power supply capacity and electricity security level, combined with the actual work,proceed from the present area and power users demand, relying on the Tongzhou grid "grid" of distribution network planning, through the10kVdistribution closing ring, grid structure tends to be reasonable, and power supply radius is greatly shortened, will effectively reduce the loss of line, thearea of energy-saving emission reduction will have a great positive role in pushing forward, so as to improve the reliability of power supply, improve the living environment in Tongzhou area.Tongzhou Longhu switching station due to two higher power grounding in different ways,10kV closed loop operation side will cause large loop current, therefore, selected Longhu switching station as a typical case.Through the analysis of calculation of loop transient current closed loop current, and the closed loop operation of the switching station bus, the feeder power flow occurs when a ground fault and by combing loaddistribution analysis, to determine the effect of operation, closed loop current on the scheduling of relay protection and take corresponding measures.