Title :
Tree initiation characteristics in LDPE with different crystallinities
Author :
Kim, W.S. ; Lee, Y.H. ; Lee, H.G. ; Jang, D.U. ; Park, Y.G. ; Lim, K.J. ; Kang, S.H. ; Ryu, B.H.
Author_Institution :
Dept. of Electr. Eng., Chonbuk Nat. Univ., Chonju, South Korea
Abstract :
It is well known that the degree of crystallinity is an important quantitative concept. By itself, or in consort with other key structural variables, it governs a variety of microscopic and macroscopic properties. In this experiment, we changed conditions of crystallization to study characteristics of apparent tree inception stress and electrical tree propagation in different degrees of crystallinity and we made specimens with a needle-plane electrode system of LDPE. We observed inception and propagation of electrical trees by an optical microscope interfaced with a computer and investigated the characteristics of the phase resolved PD pulses accompanying the tree propagation. As the tip radius increased, tree inception stress converged to a constant value. In addition, as the the degree of crystallinity is increased, the tree inception voltage is also increased
Keywords :
crystallisation; optical microscopy; polyethylene insulation; trees (electrical); LDPE; apparent tree inception stress; crystallinity; electrical tree propagation; needle-plane electrode system; optical microscopy; tip radius; tree inception voltage; Crystallization; Electrodes; Needles; Optical microscopy; Optical propagation; Optical pulses; Partial discharges; Stress; Trees - insulation; Voltage;
Conference_Titel :
Properties and Applications of Dielectric Materials, 2000. Proceedings of the 6th International Conference on
Conference_Location :
Xi´an
Print_ISBN :
0-7803-5459-1
DOI :
10.1109/ICPADM.2000.875749
