Effect of DC Prestressing on Periodic Grounded DC Tree in Cross-Linked Polyethylene at Different Temperatures

Periodic grounded dc trees in cross-linked polyethylene under various dc prestressing times are investigated in the temperature range of 20 °C–80 °C. Space charge behaviors in the samples during dc prestressing are simulated based on the bipolar charge transport model. The results reveal that the dc prestressing time has different effects on the tree growth at different temperatures, which is because that the space charge behavior in the sample during dc prestressing is closely related to the dc prestressing time and the temperature, and it has both promotion effect and impedance effect on the tree growth. The moderate promotion effect and impedance effect under 160 s dc prestressing at 20 °C, and the strongest promotion effect and the weakest impedance effect under 240 s dc prestressing at 40 °C result in the largest tree lengths, widths, and accumulated damages under each corresponding condition. At 60 °C and 80 °C, the lengths, widths, and accumulated damages are the largest under 240 s dc prestressing, smaller under 80 s dc prestressing, and the smallest under 160 s dc prestressing, and the reason is believed to be the growth rates reversal during the tree growth. Also it is found that the dc prestressing time has significant effects on the tree shape at 60 °C and 80 °C, which is believed to be related to the wider charge diffusion range under longer dc prestressing time. The electrical tree characteristics are discussed in detail combined with the space charge behaviors.

[1]  T. Han,et al.  Electrical tree characteristics in silicone rubber under repetitive pulse voltage , 2015, IEEE Transactions on Dielectrics and Electrical Insulation.

[2]  Marc Jeroense,et al.  HVDC Cable Systems—Highlighting Extruded Technology , 2014, IEEE Transactions on Power Delivery.

[3]  B. X. Du,et al.  Effect of pulse frequency on tree characteristics in epoxy resin under low temperature , 2016, IEEE Transactions on Dielectrics and Electrical Insulation.

[4]  Jiandong Wu,et al.  Investigation on heterocharge accumulation in crosslinked polyethylene: Experiment and simulation , 2014 .

[5]  Yi Yin,et al.  Effect of temperature on space charge trapping and conduction in cross-linked polyethylene , 2014, IEEE Transactions on Dielectrics and Electrical Insulation.

[6]  V. Englund,et al.  A versatile method to study electrical treeing in polymeric materials , 2009, IEEE Transactions on Dielectrics and Electrical Insulation.

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

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

[9]  Y. Sekii,et al.  DC tree and grounded DC tree in XLPE , 2005, CEIDP '05. 2005 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, 2005..

[10]  George Chen,et al.  Review of high voltage direct current cables , 2015 .

[11]  N. Yoshimura,et al.  Tree Initiation in Polyethylene by Application of DC and Impulse Voltage , 1976, IEEE Transactions on Electrical Insulation.

[12]  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.

[13]  Shengtao Li,et al.  Simulation of low-energy electron beam irradiated PTFE based on bipolar charge transport model , 2016, IEEE Transactions on Dielectrics and Electrical Insulation.

[14]  Kazutoshi Abe,et al.  Development of High Voltage DC-XLPE Cable System , 2013 .

[15]  M. Ieda,et al.  DC Treeing Breakdown Associated with Space Charge Formation in Polyethylene , 1976, IEEE Transactions on Electrical Insulation.

[16]  M. Cho,et al.  Charge transport properties of insulators revealed by surface potential decay experiment and bipolar charge transport model with genetic algorithm , 2012, IEEE Transactions on Dielectrics and Electrical Insulation.

[17]  L. A. Dissado,et al.  The fractal analysis of water trees: an estimate of the fractal dimension , 2001 .

[18]  E. Ildstad,et al.  Electrical treeing caused by rapid DC-voltage grounding of XLPE cable insulation , 2006, Conference Record of the 2006 IEEE International Symposium on Electrical Insulation.

[19]  Wang Huiming,et al.  Space charges and initiation of electrical trees , 1989 .

[20]  G. Chen,et al.  Electrical treeing characteristics in XLPE power cable insulation in frequency range between 20 and 500 Hz , 2009, IEEE Transactions on Dielectrics and Electrical Insulation.

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

[22]  Junzheng Cao,et al.  Mechanism of space charge formation in cross linked polyethylene (XLPE) under temperature gradient , 2015, IEEE Transactions on Dielectrics and Electrical Insulation.

[23]  Yi Yin,et al.  Effect of temperature on space charge detrapping and periodic grounded DC tree in cross-linked polyethylene , 2016, IEEE Transactions on Dielectrics and Electrical Insulation.

[24]  Treeing in polyethylene as a prelude to breakdown , 1957 .

[25]  R. Hill,et al.  A model for bipolar charge transport, trapping and recombination in degassed crosslinked polyethene , 1994 .

[26]  Liu Ying,et al.  Electrical tree initiation in XLPE cable insulation by application of DC and impulse voltage , 2013, IEEE Transactions on Dielectrics and Electrical Insulation.

[27]  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).