Study On Partial Discharge Detection Technology Of XLPE Power Cable

With the widespread application of power cables in urban power grid construction,breakdown faults caused by insulation aging,electrical dendrization and external force destruction of XLPE cables put into operation in the early stage have occurred repeatedly and presented an upward trend,which has seriously threatened the reliable operation of the cable network.As is known to all,XPLE cable is mainly laid in a variety of forms,such as tunnel,channel,pipe laying,direct buried,etc.This underground pipeline laying method causes a hindrance to the research and determination of cable working conditions.As time goes by,some XLPE cables currently in operation gradually reach the expected life.Once the fault occurs,it is very difficult to find the fault.Fault finding not only consumes a lot of manpower and material resources,and brings inestimable loss of power failure,but also affects the normal operation of residents' daily life and other industries,causing severe social impact and major economic loss.We must fully recognize the importance of the insulation condition of XLPE cable and take effective technical measures to reduce its risk of insulation failure.Therefore,the detection method of XLPE cable insulation deterioration plays a crucial role in extending the service life of XLPE cable and enhancing the safety and reliability of cable operation.Various off-line and on-line condition maintenance technologies for detecting the insulation condition have come into being,which greatly promotes the progress of power cable condition maintenance technology.At present,partial discharge detection is a direct and effective test method for the insulation condition of detection equipment.As the insulation material of crosslinked polyethylene cable is very sensitive to partial discharge,potential defects can be found in time through partial discharge detection,thus reducing the rate of sudden failure.In this paper,the generating mechanism and principle of partial discharge are analyzed in detail,and the principle,characteristics and effectiveness of off-line and on-line detection methods of partial discharge of crosslinked polyethylene cable are introduced respectively.Through the local discharge test on the body of XLPE cable and the simulation defects of its accessories,the advantages,disadvantages and effectiveness of various cable partial discharge test methods were summarized and analyzed,and the actual application situation was analyzed with examples.Finally,according to the development status of XLPE cable and the status of pd detection technology,the application status and existing problems of XLPE cable pd detection technology are given.