Test research on overvoltage withstanding characteristics of control cables

Withstanding characteristics of control cables under 50 Hz AC, DC and lightning impulse overvoltage are tested and studied, and the results show that surface discharge voltage of cable terminal tends to saturate with the increase of the pole distance; the fact that head and shield of its are treated well or not has a great effect on the withstanding characteristic of control cables; the insulating property between shield and core wires is the most unsubstantial link in the whole insulation of control cables, which can withstand more than 18 kV 50 Hz AC voltage, 45 kV positive polarity DC voltage and 40 kV negative polarity lightning impulse voltage within 30 seconds.