Electrical treeing characteristics in XLPE power cable insulation in frequency range between 20 and 500 Hz

Electrical treeing is one of the main reasons for long term degradation of polymeric materials used in high voltage AC applications. In this paper we report on an investigation of electrical tree growth characteristics in XLPE samples from a commercial XLPE power cable. Electrical trees have been grown over a frequency range from 20 Hz to 500 Hz and images of trees were taken using CCD camera without interrupting the application of voltage. The fractal dimension of electric tree is obtained using a simple box-counting technique. Contrary to our expectation it has been found that the fractal dimension prior to the breakdown shows no significant change when frequency of the applied voltage increases. Instead, the frequency accelerates tree growth rate and reduces the time to breakdown. A new approach for investigating the frequency effect on trees has been devised. In addition to looking into the fractal analysis of tree as a whole, regions of growth are being sectioned to reveal differences in terms of growth rate, accumulated damage and fractal dimension.

[1]  M. Fujii,et al.  Fractal character of DC trees in polymethylmethacrylate , 1991 .

[2]  Katsutoshi Kudo,et al.  Fractal analysis of electrical trees , 1998 .

[3]  D. W. Auckland,et al.  The influence of mechanical factors on electrical treeing , 1998 .

[4]  Hans Edin,et al.  Partial Discharges Studied with Variable Frequency of the Applied Voltage , 2001 .

[5]  J. H. Mason.  The deterioration and breakdown of dielectrics resulting from internal discharges , 1951 .

[6]  Stephen J. Dodd,et al.  A Deterministic Model for the Growth of Non-conducting Electrical Tree Structures , 2003 .

[7]  J. V. Champion,et al.  Analysis and modelling of electrical tree growth in synthetic resins over a wide range of stressing voltage , 1994 .

[8]  Ioannis G. Karafyllidis,et al.  Simulation of electrical tree growth in solid dielectrics containing voids of arbitrary shape , 1996 .

[9]  L. A. Dissado,et al.  Propagation of electrical tree structures in solid polymeric insulation , 1997 .

[10]  M. Ieda,et al.  A consideration of treeing in polymers , 1972 .

[11]  J. H. Mason.  Breakdown of Solid Dielectrics in Divergent Fields , 1955 .

[12]  Len A. Dissado.  Understanding electrical trees in solids: from experiment to theory , 2002 .

[13]  Fumitoshi Noto,et al.  Voltage and frequency dependence of tree growth in polyethylene , 1974 .

[14]  K. Kudo,et al.  Fractal characteristics of real electrical trees , 1992, [1992] Proceedings of the 4th International Conference on Conduction and Breakdown in Solid Dielectrics.

[15]  L. Pietronero,et al.  Fractal Dimension of Dielectric Breakdown , 1984 .

[16]  Len A. Dissado,et al.  Understanding electrical trees in solids: from experiment to theory , 2001, ICSD'01. Proceedings of the 20001 IEEE 7th International Conference on Solid Dielectrics (Cat. No.01CH37117).

[17]  J M Cooper,et al.  The influence of physical properties on electrical treeing in a cross-linked synthetic resin , 1990 .

[18]  L. A. Dissado,et al.  A deterministic model for branched structures in the electrical breakdown of solid polymeric dielectrics , 2000 .

[19]  G. Stevens,et al.  Stochastic modelling of electrical treeing: fractal and statistical characteristics , 1990 .

[20]  G. Chen,et al.  Propagation mechanism of electrical tree in XLPE cable insulation by investigating a double electrical tree structure , 2008, IEEE Transactions on Dielectrics and Electrical Insulation.

[21]  R. Densley,et al.  An Investigation into the Growth of Electrical Trees in XLPE Cable Insulation , 1979, IEEE Transactions on Electrical Insulation.

[22]  H. R. Zeller,et al.  A fractal model of dielectric breakdown and prebreakdown in solid dielectrics , 1986, Conference on Electrical Insulation & Dielectric Phenomena — Annual Report 1986.

[23]  Yasuo Suzuoki,et al.  A novel physical model for partial discharge in narrow channels , 1999 .

[24]  John C. Fothergill,et al.  Electrical degradation and breakdown in polymers , 1992 .