Effect of High Temperature on Electrical Treeing of Polypropylene with Repetitive Pulse Voltage

摘要

High temperature has important influences on the electrical treeing, affecting the safety of insulations. The pulse voltage existing in HVDC cable accelerates the aging of polymers. In this paper, the effects of ambient temperature and pulse polarity on the electrical tree characteristics under different pulse amplitudes were investigated. The rise time of the pulse voltage is 100 µs, and the tail time is 120 µs. The results show that with the temperature increasing, the branches become darker and wider. The growth rate increases when the ambient temperature raises from 70 to 110 °C. The growth rate decreases when the ambient temperature raises from 110 to 130 °C. The accumulated damage of positive voltage is larger than that of negative voltage with different amplitudes. This is caused by the different characteristics of the injected charge carriers.