Open AccessField verification of a novel and simple partial discharge detection method for generator applications
Author(s) -
Herath Thathsara,
Kumara Sarath,
Bandara Kapila,
Wijayakulasooriya Janaka,
Fernando Manjula,
Jayanatha Gawasinghe A.
Publication year - 2020
Publication title -
iet science, measurement and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.418
H-Index - 49
eISSN - 1751-8830
pISSN - 1751-8822
DOI - 10.1049/iet-smt.2018.5631
Subject(s) - partial discharge , electromagnetic coil , generator (circuit theory) , polarity (international relations) , signal (programming language) , algorithm , computer science , voltage , similarity (geometry) , power (physics) , electronic engineering , materials science , computational physics , physics , artificial intelligence , engineering , electrical engineering , chemistry , biochemistry , quantum mechanics , image (mathematics) , cell , programming language
This study introduces a simple and novel partial discharge (PD) detection method for generator condition monitoring applications. The proposed method uses statistical operator ‘Variance’ which is proportional to the power of an electrical signal. It was validated by field measurement conducted at four in service hydro‐generators: two having heavily aged windings and the other two having identical new. First, accuracy of detecting PD pulses was verified by comparing with wavelet‐based method. The proposed method detected all the PD pulses with a ‘Precision’ higher than 90% and recall of 100%. As the second step phase resolved PD (PRPD) patterns generated using the proposed method were compared with commercial PD monitoring systems. It was found that the overall similarity was above 0.75. Finally, extracted PD pulses were used to calculate the polarity wise dissipated PD energies. The calculated energies were correlated with identified PD sources through series of off‐line tests and visual inspections. It was observed that discharges due to loosen windings and corona activity were well correlated with estimated PD energies. All these validation processes indicated that the proposed method effectively and accurately detect PD pulses and can be used as a diagnostic tool for generator applications.