Research On The Deterioration And Stability Of High Voltage Cross-linked Polyethylene Cable

In order to meet the demand of economic development for power consumption and solve the problem of growing load,it is necessary to strengthen the construction of the cable line,which should take many factors into consideration,such as the route alignment of lines,electromagnetic environment,city planning and so on.Cross-linked polyethylene cable has been widely used in the power system because of its advantages of less land occupation and convenient construction.High voltage cable line plays an important role in power transmission,and its insulation can not be self-recovered,which will cause serious economic losses and social impact once an internal defect causes an accident.Therefore,it is urgent to improve the reliability and stability of cross-linked cable.In this paper,the mechanism of insulation cable degradation is studied,and the influence of water tree,electrical tree development,thermal deterioration,mechanical deterioration and electrical deterioration on insulation is analyzed.Meanwhile,the dangerous point of cable insulation failure in the process of cable manufacture and construction is studied,and the existing insulation monitoring experiments are compared and analyzed in order to get a practical method for insulation monitoring and the best time for cable replacement,which reduces the damage to the cable and the amount of labor caused by the test.At last,some technical index of cross-linked cable insulation materials such as the change of tensile strength and elongation at break are tested by method of artificial deterioration,which verifies the feasibility of the detection and the economy of optimum time of the replacement for cable.