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Insulation diagnosis method for generator winding by measuring microwaves associated with dielectric breakdown
Author(s) -
Kawada Masatake,
Kawasaki ZenIchiro,
Matsuura Kenji,
Musashiya Toshio,
Kuroki Satoru,
Osawa Teruya,
Tanaka Hiroki
Publication year - 2000
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/(sici)1520-6416(20000715)132:1<38::aid-eej6>3.0.co;2-9
Subject(s) - microwave , partial discharge , materials science , voltage , electrical engineering , dielectric , generator (circuit theory) , dielectric strength , amplitude , breakdown voltage , dielectric withstand test , acoustics , composite material , optoelectronics , optics , engineering , physics , telecommunications , power (physics) , quantum mechanics
Partial discharge (PD) within voids in a solid insulating system is a symptom and/or a direct cause of deterioration of a generator winding. It is reported that PD is a very short duration current and/or voltage pulse, about 1 to 5 ns. Generally PD emits an electromagnetic wave which is a broadband range signal (≈ gigahertz). Therefore, we developed a new system for detecting the electromagnetic wave, especially microwaves (gigahertz) associated with a material defect of the winding. From the point of view of preventing accidents of insulation breakdown, it is important to assess the condition of the winding. We applied our system to a dielectric breakdown test to learn the relation between the characteristics of the microwaves and the insulation condition of the winding. The dielectric breakdown test is believed to be useful for estimating the minimum breakdown voltage which is a criterion of the insulation condition of the winding. Experimental results showed that this system was able to assess the insulation condition by measuring the number of pulses and the amplitude of the microwaves per voltage cycle. © 2000 Scripta Technica, Electr Eng Jpn, 132(1): 38–45, 2000