Title :
Silicone composites for HV applications based on microvaristors
Author :
Donzel, L. ; Christen, T. ; Kessler, R. ; Greuter, Felix ; Gramespacher, H.
Author_Institution :
Corp. Res., ABB Schweiz AG, Baden, Switzerland
Abstract :
Microvaristors are small sintered particles of doped ZnO with strongly nonlinear electrical properties similar to those of the varistor ceramics. Composite materials based on a silicone matrix filled with microvaristor powder have a nonlinear current-voltage relation and can be used for field grading applications. The field dependence of the conductivity is determined by the properties of the filler particles, and can be tuned by modifying the formulation of the microvaristors and the sintering conditions as sintering time or temperature. In this contribution, we describe the nonlinear field grading material, and report on the development of a prototype field-grading element for a dry and compact high voltage termination, which has been successfully tested.
Keywords :
HVDC power transmission; composite materials; electrical conductivity; permittivity; powders; power cable testing; silicone rubber; sintering; varistors; zinc compounds; HV applications; ZnO; compact high voltage termination; composite materials; doping; dry high voltage termination; field grading applications; field-dependent conductivity; microvaristor powder-filled silicone matrix; microvaristors; nonlinear current-voltage relation; nonlinear electrical properties; prototype field-grading element; silicone composites; sintering conditions; small sintered particles; varistor ceramics; Ceramics; Composite materials; Conducting materials; Conductivity; Powders; Prototypes; Temperature dependence; Varistors; Voltage; Zinc oxide;
Conference_Titel :
Solid Dielectrics, 2004. ICSD 2004. Proceedings of the 2004 IEEE International Conference on
Print_ISBN :
0-7803-8348-6
DOI :
10.1109/ICSD.2004.1350376
