Simulation And Experimental Study On10kV Three-core Cable Temperature Distribution Characteristics And Conductor Temperature Calculation

With china’s urbanization advancement speeding up unceasingly, the city’s power loadincreases year by year and distribution intensive. Because compared with overheadtransmission line，the underground cable line don’t occupy ground’s surface, operation stablyand reliably, and don’t hinder view. The usage and demand of cities distribution network formedium voltage XLPE cable are growing. However, all kinds of urban underground pipelinesare intensive, the underground space resource becoming more and more limited. To built anew cable line will cost a long time, large investment, and long-term civil work will cause theurban traffic congestion, air quality issues such as variable. So, in the existing distributionnetwork cable resources, if can fully excavating the current-carrying capacity, will save a lotof manpower, material cost.At present, the operating distribution network10kV three-core cables’ current-carryingcapacity is mainly provide by cable manufacturers or get from calculation through the IECstandard. Due to10kV three-core cable there are many laying means, manufacturers providecurrent-carrying capacity does not apply to all; Due to the IEC standard can be calculatedgenerally laying cases three-core cable current-carrying capacity, but some assumptions ofIEC standard is not perfect enough, as well as calculation conditions are harsh, so calculatedcurrent-carrying capacity value is low. And, compared with the high voltage single core cable,10kV three-core cable operation management and maintenance aspects is not mature standardenough. Leading to10kV three-core cable can not make full use of its transmission capacity,or give up regulations set by the upper limit current-carrying capacity, long-term overloadoperation. If go on development like this, will naturally cause the waste of distributionnetwork cables’ transmission capacity, or even because of unreasonable operation, blackoutshappened, resulting in great loss.Due to10kV three-core cable are different with high voltage single core cable instructure, laying mode, operation and management. Three-core cable current-carryingcapacity setting dependent on the experimental research which simulation operatingenvironment of the scene or add a coefficient before the calculation model of high voltagesingle core cable thermal road, but did not give a specific instructions, theoretical research isless.This paper mainly study on10kV three-core cable internal temperature field distributioncharacteristics and the conductor temperature calculation which general used in distributionnetwork. First of all, use the simulation method analysis the internal temperature field distribution characteristics under steady state and transient condition which in circumstancesthat single no external heat source, and through experiment verification; And in the conditionof cable group pipe laying have external heat source uneven distribution, analysis if singlecable internal temperature field distribution be affected or changed; At the same time, thesimulation analysis of the cable group pipe laying different load peak, to get temperature fielddistribution and current-carrying capacity of cable group; Finally puts forward10kvthree-core cable steady state simplified heat road model that use thermal path method tocalculate the temperature of conductor, and through experiment verify the accuracy of thismodel.