Title :
An Online UHF PD Monitoring System for Power Transformer and Its Applications
Author :
Liu, Mingjun ; Li, Zhaohui
Author_Institution :
Coll. of Hydro Power & Inf. Eng., Huazhong Univ. of Sci. & Technol., Wuhan, China
Abstract :
It is widely accepted that failure due to insulation defects are often preceded by some form of partial discharge (PD) activity in high voltage (HV) equipments. This study describes industrial application of ultra high frequency (UHF) PD detection technique on large oil-immersed power transformers. To suppress external interference internal UHF sensors were designed and successfully installed to 4 power transformers for their insulation assessment. As the frequency band of the UHF sensor was 500-1500 MHz, envelope detection technique was employed to extract UHF signals. Typical UHF PD patterns were recorded during PD acceptance test using the monitoring system. The results reveal that UHF PD measurements can detect small level of discharges with good sensitivity. Finally, the influence of external impact pulses such as lightning strike pulses, switching operation pulses was studied as well. The system has been put into service to 4 power transformers.
Keywords :
partial discharges; power transformers; UHF sensor; envelope detection technique; frequency 500 MHz to 1500 MHz; high voltage equipments; insulation assessment; lightning strike pulses; oil-immersed power transformers; online UHF partial discharge monitoring system; switching operation pulses; ultra high frequency partial discharge detection technique; Condition monitoring; Electrical equipment industry; Envelope detectors; Frequency; Interference suppression; Partial discharges; Power transformer insulation; Power transformers; Pulse transformers; System testing;
Conference_Titel :
Power and Energy Engineering Conference (APPEEC), 2010 Asia-Pacific
Conference_Location :
Chengdu
Print_ISBN :
978-1-4244-4812-8
Electronic_ISBN :
978-1-4244-4813-5
DOI :
10.1109/APPEEC.2010.5449362
