Original scientific paper

Partial discharge monitoring of power transformers by UHF sensors

Stefan Tenbohlen ; UTRA

Abstract

Electrical energy networks’ reliability is driven by both the quality and the reliability of its electrical equipment, e.g., power transformers. Local failures inside their oil / paper insulation can cause a breakdown resulting in major outage and penalty costs. Power transformers are tested on partial discharge (PD) activity at a factory routine test. In addition, UHF PD monitoring can be used to prevent harmful events during service. Therefore,
continuous monitoring can be beneficial compared to singular diagnostic measurements; diagnostic PD measurements provide snapshot information which lacks trend information. Also, temporary measurements can cause misleading interpretations due to the volatile nature of PD. UHF PD monitoring systems can be calibrated for comparability in a two-step procedure, including the sensor characteristic. UHF sensor positions must be selected for good coverage of the active part, high sensitivity, and safety reasons.

Keywords

power transformer condition assessment, UHF PD calibration, UHF PD monitoring, UHF sensor positioning

Hrčak ID:

242408

URI

https://hrcak.srce.hr/242408

Publication date:

8.7.2020.

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