The Mechanism and Diagnosis of Insulation Deterioration Caused by Moisture Ingress into Oil-Impregnated Paper Bushing

Bo Qi, Quanmin Dai, Chengrong Li, Zipeng Zeng, Mingli Fu and Ran Zhuo
Additional contact information
Bo Qi: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Chang Ping District, Beijing 102206, China
Quanmin Dai: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Chang Ping District, Beijing 102206, China
Chengrong Li: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Chang Ping District, Beijing 102206, China
Zipeng Zeng: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Chang Ping District, Beijing 102206, China
Mingli Fu: Electric Power Research Institute of China Southern Power Grid, Guangzhou 510530, China
Ran Zhuo: Electric Power Research Institute of China Southern Power Grid, Guangzhou 510530, China

Energies, 2018, vol. 11, issue 6, 1-12

Abstract: The healthy state of insulation in oil-impregnated bushings is traditionally evaluated by tanδ and capacitance at power frequency and mostly at 10 kV in the test standard. However, there has frequently been insulation accidents induced by moisture ingress (MI) for bushings that have passed the standard. The mechanism and new diagnostic features for MI into bushings were not distinct enough and an accurate test method is urgently needed research. To address this technical gap, a bushing model with a transparent sheath was designed and an ultrasonic humidifier device was adopted to simulate the environment of MI in bushings and recorded by digital camera. The parameters of dielectric dissipation factor, capacitance, partial discharge (PD), frequency domain response, and moisture content in oil were measured at room temperature with time. The results presented that both the increment dissipation factor at low frequency of 0.001 Hz and the increment dissipation factor of 1.2 U m could be used for detecting the earlier insulation defect of oil-impregnated paper (OIP) bushings. The phase resolved partial discharge (PRPD) can serve as the diagnostic basis of the severe state (S 3 ) of insulation deterioration caused by MI into bushings around the phases of 0–117°, 151–303°, and 325–360°. The research findings would provide a useful reference for the condition diagnosis and maintenance of OIP bushings. Especially, the increment detection of Frequency Domain Spectroscopy (FDS) at the frequency of 1 mHz and 10 kHz was recommended firstly for the operative bushings in real sites.

Keywords: bushing; moisture ingress; insulation deterioration; fault diagnosis (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2018
References: View complete reference list from CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
https://www.mdpi.com/1996-1073/11/6/1496/pdf (application/pdf)
https://www.mdpi.com/1996-1073/11/6/1496/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:11:y:2018:i:6:p:1496-:d:151348

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().