Title :
New approach to diagnostic method of water trees
Author :
Nagao, Masayuki ; Tokoro, Tetsuroh ; Yokoyama, Akihiko ; Kosaki, Masamitsu
Author_Institution :
Dept. of Electr. & Electron. Eng., Toyohashi Univ. of Technol., Japan
Abstract :
A novel method for the detection of high-field AC conduction loss current containing harmonics in polymeric insulating materials is presented. The method is based on the use of the unbalanced operation of a current-comparator-type capacitance bridge and the deconvolution technique of signal processing. This technique was experimentally applied to the diagnosis of water trees in CV power cables by detecting the waveform of the high-field AC conduction current of the cables with and without water tree degradation. The distortion of the current waveform measured for the water-tree-degraded cable appeared to be larger than that observed for nondegraded cables. This result might be related to the nonlinear electric field dependence of the AC conduction loss current around water trees
Keywords :
cable insulation; cable testing; electric breakdown of solids; insulation testing; maintenance engineering; organic insulating materials; polymers; power cables; CV power cables; XLPE cables; current harmonics detection; current-comparator-type capacitance bridge; deconvolution technique of signal processing; detection of high-field AC conduction loss current; diagnosis of water trees; diagnostic method of water trees; high-field AC conduction current; nonlinear electric field dependence; polymeric insulating materials; unbalanced operation; water tree degradation; waveform; Bridge circuits; Capacitance; Conducting materials; Deconvolution; Degradation; Plastic insulation; Polymers; Power cables; Signal processing; Trees - insulation;
Conference_Titel :
Electrical Insulation, 1990., Conference Record of the 1990 IEEE International Symposium on
Conference_Location :
Toronto, Ont.
DOI :
10.1109/ELINSL.1990.109759
