|
|
|
| Research on the New Hot-line Monitoring Method of XLPE Power Cable |
| QU Hong-xin ， SUN Yao |
| The Third Railway Survey and Design Institute Group Corporation，Tianjin 300251，China |
|
|
|
Abstract Research purposes: XLPE cables can be widely used in various places. Early degradation of XLPE cables researches may extend its using life.
Research methods: In this paper an accurate water tree model has been created .We have successfully developed a new hot-line diagnostic method called”high frequency superposition method”.We superpose a voltage with high frequency but low amplitude on the shielding layer of power cables to make the loss current more obvious. Then we use fractal methods to analyze loss current signals collected.
Research results: Degradation of XLPE cable by water trees gives rise to harmonics in the loss current. Harmonic components arise as a result of nonlinear voltage-current characteristic of water trees. The fractal dimension of loss current waveform increases because of the growth of harmonics. We calculate 3 fractal dimensions including capacity， information and correlation. We discuss the interrelationship between fractal dimension and harmonics.
Research Conclusions: The fractal dimension provides an extremely good indication of the state of degradation which can be used as a judgment for hot-line dielectric degradation.
|
|
Received: 06 March 2007
|
|
|
|
|
|
[1]Sverre Hvidsten, et al. Correlation between AC breakdown strength and low frequency dielectric; loss of water tree aged XLPE cables[ J ] . IEEE Trans on PD , 1998，13( 1):40
[2]袁检，罗俊华，等.XLPE电力电缆介质引发水树枝机理 的研究[J].高电压技术，2002, 28(2):8.
[3]Yukihiro yagi, Hideo Tanaka, Hitoshi Kimura. Study on Di- agnostic Method for water Treed XLPE Cable by Loss Cur- rent Measurement [A].Conference on Electrical Insulation and Dielectrjc Phenomena[ C]，Atlanta , GA , USA , 1998.
[4]王兴元.复杂非线性系统中的混沌[M].电子工业出版 社，2003.
[5]Takao kumazawa , Masahiro Hotta , Shinchi Sugiyama. A New Hot-line Diagnostic Method for XLPE cables: AC Superpo- sition Method[ A].Proceedings of the IEEE International Conference on Properties and Applications of dielectric Ma- Terials[C]. Seoul Korea,1997.
[6]Mandelbrot B BWallis J R. Stone long-run properties of geographical Records[J]. Water Resour Res,1969,5(2): 321-340.
[7]Mandelbrot B BWallis J R. Robustness of the rescaled ranged R/S in the measurement of noncyclic long run statis- tical dependence[J ] . Water Res ,1969 , 5 ( 5):967-988
|
|
|
|
2007, Vol. 24 
