Comparison of the detectability of an artificial surface discharge fault on a 110-kV-XLPE high-voltage cable under different On-Site test voltages

Abstract:
The On-Site measurement and diagnosis of High-Voltage cable systems is a compromise between the compactness of the measurement system and the possibility of using a voltage that is as similar as possible to the operating voltage. Due to strong capacitive properties of the cable system a high reaction power demand needs to be covered. Especially in the high-voltage level resonance testing technique has become widely accepted. Since this test method is associated with limitations due to the size of the test device itself and thus with rising costs, alternative test voltages such as ‘Damped AC’, ‘0,1-Hz-VLF-Sine’ and ‘0,1-Hz-VLF-Rectangle’ are gaining in importance. These alternative test voltages, differ from the operating voltage in shape and frequency, so the investigation of these voltages under reproducible environment for their ability to detect a fault is necessary. In the past, comparative tests were performed on needle defects in an insulation system to determine whether an On-Site test voltage type can break down this operationally dangerous fault within a test time. Due to the possibility of detecting a fault during a test by means of partial discharge measurement, artificial, reproducible faults serve to find further criteria for the comparison of the test voltage types. In this study, therefore, a comparison of the partial discharge characteristics of different test voltage types is to be carried out on an artificial, reproducible surface discharge fault on a 110-kV-XLPE high voltage cable.