132kV XLPE Cable Sheath Fault Locating and Repairing: Techniques and Challenges

High voltage cable sheath fault locating techniques have developed drastically during the past few years. With all available technologies, Engineers are able to pre-locate sheath faults initially and then pinpoint (locate) the exact spot using equipment that work by pulse injection method, where the voltage drop detects the fault location wherever leakage current is detected. At the fault location, the voltage pulses discharge into the surrounding ground due to the fault resistance and form voltage gradient on the earth surface, which can be detected by suitable equipment. However, with all the advanced equipment and technologies, there are still some challenges that require further studies and developments including cases where faults are under asphalt roads and clear signals are difficult to obtain for exact location detection. In this paper, we aim to go through the currently applied methods for 132 kV Transmission cable sheath fault locating as experienced in Dubai Electricity and Water Authority (DEWA), and the repair techniques given the various cases that could be faced at site, and also the challenges associated in terms of limitations and special cases.