This presentation focuses on the online measurements of Partial Discharge activity on a range of HV assets such as cables, switchyards, rotating machines, MV switchgear and GIS, transformers and bushings using the latest measurement and interference rejection techniques.  Several case studies are presented showing the benefit of each of the techniques to prevent catastrophic asset failure.  

Overview

Fundamentally, the desired result of a diagnostic test is to determine the status of the apparatus on whether an abnormality is detected, how critical it is, and how soon it will require attention. The justification for the tests is the benefit of having data to support decisions that affect the reliability of the asset. Short of limiting the use of an asset, diagnostic testing is the only reliable and economical approach in ensuring its longevity for reliable and safe operation.

Insulation failure in HV power equipment failure is mostly due to the cumulative effect of different deterioration processes acting upon the insulation in service. Because of the number of possible insulation failure mechanisms, no single diagnostic method can assess the insulation condition and predict the remaining service life of dielectric with 100% confidence but they all can give information on the quality of the insulation. Partial Discharge activity is produced by incipient faults in HV insulation and is regarded as one of the best indicators of insulation condition providing an early warning against insulation faults. The PD activity can be detected via a range of sensors, instruments and measurement techniques both covered in the IEC 60270 and IEC TS 62478 Standards.

This presentation focuses on the online measurements of Partial Discharge activity on a range of HV assets such as cables, switchyards, rotating machines, MV switchgear and GIS, transformers and bushings. The latest measurement techniques and interference rejection techniques ranging from simple frequency filtering to GPS synchronised measurements are introduced. Several case studies are presented showing the benefit of each of the techniques to prevent catastrophic asset failure.