Summary
This paper addresses the challenges of locating partial discharge (PD) sources in gas insulated switchgear (GIS), with particular focus on cable terminations. Although the ultra-high frequency (UHF) time of flight (TOF) method is widely used for on-site PD localisation, it assumes a constant signal propagation velocity—an assumption that does not hold in cable terminations due to the presence of multiple dielectric materials. This often results in significant localisation errors and increases the risk of ineffective or unnecessary maintenance.
Read more Read lessA case study is presented in which conventional TOF analysis incorrectly located a PD source outside solid insulation, while a subsequent failure revealed the defect within an epoxy insulator, highlighting the practical consequences of propagation velocity variations.
To address this limitation, an alternative TOF methodology is proposed that incorporates a measured overall propagation delay between sensors obtained through signal injection. By combining this delay with the measured time difference of arrival of PD pulses, the method enables more accurate localisation within complex cable termination structures. The approach improves reliability without invasive investigation and is validated through site measurements and case study analysis.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | D1_11949_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | United Kingdom |
| Study committees | |
| File size | 629 KB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
GOODWIN Amelia - Siemens Energy United Kingdom; COAPES Graeme - Siemens Energy United Kingdom; BOLTZE Matthias - Siemens Energy Germany; MACLEOD Finlay - SP Energy Networks United Kingdom; BOYD Iain - SP Energy Networks United Kingdom
Keywords
GIS cable termination, partial discharge, time-of-flight, velocity of propagation, condition monitoring
