Partial Discharge Monitoring in Power Transformers Using Ultra High Frequency Techniques
Keywords:
partial discharge, power transformer, ultra high frequency, online monitoring, insulation diagnosticsAbstract
Partial discharge is a localized electrical phenomenon that can indicate developing insulation defects in power transformers. Reliable monitoring is valuable because insulation deterioration may progress while the transformer remains in service. This review examines ultra high frequency detection of partial discharge, with emphasis on sensor installation, electromagnetic propagation, signal acquisition, calibration, and integration with complementary diagnostic methods. A structured narrative synthesis of the literature addresses the physical basis of detection and the practical factors governing monitoring performance. The reviewed work supports UHF sensing as a useful approach for online monitoring, particularly when the transformer tank attenuates external electromagnetic interference. However, sensitivity depends on the discharge location, propagation path, antenna response, installation geometry, and acquisition chain. UHF amplitude is not automatically equivalent to apparent charge, and immunity to interference is not absolute. Drain-valve and dielectric-window sensors offer different installation opportunities, while synchronized high-frequency electrical and acoustic measurements can strengthen interpretation. The discussion develops a practical framework for commissioning, event validation, trend analysis, and maintenance escalation without treating proposed procedures as experimentally demonstrated results. UHF monitoring is most defensible as part of a calibrated, asset-specific diagnostic system that combines reliable signal capture with contextual evidence and engineering judgment.
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