Title :
Charging and discharging currents in composite polyamide dielectrics
Author :
Sussi, M.A. ; Raju, G. R Govinda
Author_Institution :
Dept. of Electr. Eng., Windsor Univ., Ont., Canada
Abstract :
Transient charging and discharging currents in composite polyamide dielectrics (Nomex-Polyester-Nomex) which arise after a sudden application or removal of a step voltage were evaluated over a range of temperatures from 70 to 200°C in steps of 10°C, and for electric field stress in the range of 0.23-9.84 MV/m. The effect of electrode materials, which were formed by vapor deposition, was also investigated. The observed charging and discharging currents were dissimilar. At constant high temperatures the charging currents decayed very slowly with time according to the power law I(t)=A(t)t-n, where the decay index was n≃0.1, with n increasing with decreasing temperatures. At lower temperatures the observed discharging currents also decayed according to t-n with the value of n varying in the range of 0.3-1.0 depending upon the temperatures
Keywords :
composite insulating materials; dielectric losses; dielectric polarisation; electric breakdown of solids; organic insulating materials; polymer films; thermally stimulated currents; 70 to 200 C; Nomex-Polyester-Nomex; composite polyamide dielectrics; decay index; dielectric losses; discharging currents; electric field stress; poling temperature; power law; step voltage; transient charging current; vapor deposition; Absorption; Dielectric losses; Dielectric materials; Electrodes; Equations; Frequency; Stress; Temperature dependence; Temperature distribution; Voltage;
Conference_Titel :
Electrical Insulation and Dielectric Phenomena, 1992. Annual Report. Conference on
Conference_Location :
Victoria, BC
Print_ISBN :
0-7803-0565-5
DOI :
10.1109/CEIDP.1992.283239
