Our Approach to Partial Discharge Testing on Power Transformers

Description

The methodology included three main steps:

Survey and periodic measurements

Continuous monitoring and analysis

Localization of defects

Various detection technologies were applied, including acoustic sensors, HFCT sensors, UHF drain valve sensors, ultrasonic and thermal scanning—all in line with IEC, IEEE, and CIGRE guidelines.

Key monitoring features involved automatic differentiation of PD and noise, high sampling rates, PRPD graphs, automated alarms, criticality indexing, and customizable monitoring units.

Case study findings:

High PD activity was detected after continuous monitoring.

Defect locations were identified using the described methodology.

DGA (Dissolved Gas Analysis) showed high acetylene levels (a PD indicator).

Upon investigation, mechanical defects and carbonization were confirmed.

After rectification, PD levels dropped significantly, and acetylene was no longer detected in the DGA report, confirming successful mitigation.

✅ In short: The PD monitoring system successfully detected defects, localized the issue, and guided corrective measures, which restored the transformer’s condition.