Fault Diagnosis Of High Voltage Cable Based On Metal Sheath Grounding Current

With the progress of science and technology, science and technology for the power system industry brought earthshaking changes in land cover, especially for high voltage cable applications has been the rapid development. Because of its good power supply reliability, friendly e nvironment and the beauty of power supply, the high voltage cable has been applied in a lot of power supply system in the city. The power cable voltage level of 110 k V or more, due to the relatively large power load, the voltage and current level is relatively high, so the high voltage cable with single core structure. There will be this kind of special structure inevitably induced sheath voltage. In this case sheath is difficult to avoid a grounding current flows.Causes the arrangement of the structure of the high voltage cable, high-voltage cable, high-voltage cable of the induced voltage is generated according to the single core high voltage power cable grounding current were analyzed. Analysis and mechanism of current, discuss the relationship between the high voltage cable connected to current and cable arrangement mode, load operation and cable grounding. Using the electromagnetic simulation software ATP-EMTP on the cable cross connection of commutation failure, cross connection box is damaged, damaged, and sheath of short circuit and open circuit fault simulation analysis, established a mathematical model for calculating the cable sheath current, were compared between the normal operation and sheath sheath grounding current situation and failure time th e operation of ground current, establish the high-voltage current operation of grounding current based on the evaluation system, provide the technical basis for the new cable online monitoring and fault of high voltage cable erection after acceptance and transformation of the old cable and put forward the idea of metal sheath grounding current of high voltage cable on-line monitoring system based on.