On-Line Cable PD Testing

William G. Higinbotham, EA Technology, LLCFeatures, Winter 2022 Features

Imagine this: A new hyper-scale data center is built in rural New Jersey. It has more than 100 25 KV cables. Six months into operation, a cable termination fails catastrophically, and the forensic investigation determines that termination workmanship was lacking. Partial discharge caused tracking, and the cable flashed over. But that’s not the nightmare scenario. The nightmare scenario is that the …

Detecting Partial Discharge on Medium-Voltage Cable Accessories

Michel Trepanier and Claude Tremblay, Hydro-Quebec; Lionel Reynaud, Hydro-Quebec Research Institute; and Mathieu Lachance, OMICRON electronics CanadaFeatures, Winter 2022 Features

Hydro-Quebec (HQ) is a major Canadian utility that manages the generation, transmission, and distribution of electricity to more than 3.8 million customers. Its distribution network includes over 12,000 km (7,456 miles) of medium-voltage underground distribution cables and more than 600,000 accessories — each with potential for failure. Medium-voltage (MV) underground cable systems are a critical part of the distribution network …

Acceptance and Maintenance Testing for Medium-Voltage Electrical Power Cables – Part 1 of 3

Thomas D. Sandri, Protec Equipment ResourcesFeatures, Winter 2022 Features

As time progresses and a cable system ages, the system’s bulk dielectric strength degrades. During this aging process, artifacts such as water trees, delamination, voids, and shield corrosion raise the local stress placed on the cable during normal operation. The exact way in which the strength of a device degrades will depend upon many factors including voltage, thermal stresses, maintenance …