XLPE power cable is widely used in grid system for its series of merits. Especially in cities, for the requirement of network structure adjustment and city planning, the mount of cable line increases continuously. At present, there are many XLPE cable lines of 110KV voltage class in service and it is on the swift growth trend. For the power cables in service, it is necessary to carry out on-line insulation monitoring and diagnosis so as to master its insulation condition. The cable lines of 110KV voltage cl...