Investigation of damage-behavior in cast epoxy resin coils under thermal and electrical stress with the help of partial discharge (PD) measurements

Author

Beyer, M. ; Borsi, I.I. ; Oelert, L.

Author_Institution

Schering-Inst. for High Voltage Eng. & High Voltage Plants, Hannover Univ., Germany

fYear

1991

fDate

8-12 Jul 1991

Firstpage

695

Abstract

Some results of step test investigations of the damage caused by thermal stress in cast epoxy resin coils are presented. The thermal stress is introduced from outside by way of a liquid heat transmission insulating medium as well as inside with help of current heat losses. The stress situation considered simulates the overcurrent and short circuit behavior of real dry-type transformers. With internal heating-up it is possible to investigate the superposition of thermal and mechanical stresses caused by overcurrent. Three different specimens are considered. These are laboratory model coils with about two and ten turns and industrially manufactured cast epoxy resin dry-type coils. The influence of the winding wire insulation is examined on laboratory model coils. Finally, the PD stress and PD damage behavior of simplified model arrangements is considered in comparison with casting epoxy resin dry-type transformers

Keywords

coils; high-voltage techniques; organic insulating materials; partial discharges; transformer insulation; PD damage behavior; PD stress; cast epoxy resin coils; current heat losses; damage-behavior; dry-type transformers; electrical stress; internal heating; laboratory model coils; liquid heat transmission; mechanical stresses; overcurrent behavior; short circuit behavior; step test investigations; thermal stress; winding wire insulation; Circuit simulation; Coils; Dielectric liquids; Electrical equipment industry; Epoxy resins; Laboratories; Power transformer insulation; Propagation losses; Testing; Thermal stresses;

fLanguage

English

Publisher

ieee

Conference_Titel

Properties and Applications of Dielectric Materials, 1991., Proceedings of the 3rd International Conference on

Conference_Location

Tokyo

Print_ISBN

0-87942-568-7

Type

conf

DOI

10.1109/ICPADM.1991.172160

Filename

172160