Enhancing Predictive Maintenance of 11kV Distribution Networks-offline Partial Discharge Testing Using Damped AC Signals

Discharge (PD) testing with Damped AC (DAC) signals. As cable systems across the region continue to age under increasing electrical load and environmental stress, the program aimed to proactively identify insulation degradation and mitigate the risk of unplanned outages through condition-based interventions. The diagnostic approach employed DAC-based PD testing, a non-destructive technique compliant with IEC 60270 and IEEE 400 standards, to evaluate the insulation health of medium-voltage cables and their joints. The program targeted 11 high-density service areas between January 2023 and December 2024, testing 583 cables across approximately 448.5 km of the network. Decisions to replace cable segments were made based on the presence and severity of PD activity, with a defined threshold of 1000 pC and criticality depending on the

PD inception voltage. The program resulted in 246 corrective actions, with 133.9 km of cable replaced and an additional 85 circuits earmarked for follow-up. A key element of the initiative was its datadriven methodology, which not only optimized resource allocation but also provided insights into cable joint quality and installation workmanship. A significant outcome was the substantial reduction in joint-related cable faults, from 143 recorded incidents (over a four-year period beginning in 2020) down to 30 following intervention. Several areas have since operated for over two years without a single failure, validating the program’s effectiveness. In conclusion, this paper demonstrates the practical benefits of DAC-based PD testing in enhancing the reliability, efficiency, and resilience of Kuwait’s distribution network. By integrating advanced diagnostics into the asset management process, the program laid the groundwork for a sustainable, scalable maintenance model that will continue to expand across the remaining regions of the country.