Showing papers by "Trevor Blackburn published in 1994"
03 Jul 1994
TL;DR: In this paper, a multi-stress aging test rig for the purpose of accelerated life tests of high voltage stator bars is presented, which employs electrical, mechanical, thermal and frequency aging at 500 Hz to replicate the operating stresses commonly found in high voltage rotating machines.
Abstract: This paper discusses a multi-stress aging test rig for the purpose of accelerated life tests of high voltage stator bars. The test rig employs electrical, mechanical, thermal and frequency aging at 500 Hz to replicate the operating stresses commonly found in high voltage rotating machines. New stator bars are used in the rig to allow the tracking of aging events from initial, non-stressed, values. Partial discharge analysis is used as the primary indication of aging phenomena. The new stator bars will be aged for a period of greater than one year, and, as a result, only preliminary measurements are presented. >
1 citations
03 Jul 1994
TL;DR: In this article, the interaction between successive partial discharges (PDs) in SF/sub 6/ have been extensively studied, but little attention has been given to the interactions between successive PDs.
Abstract: While partial discharges (PD) in SF/sub 6/ have been extensively studied there has been little attention given to the interaction between successive PDs. Repetitive discharges may affect the characteristics of subsequent PDs in the same general location so that theoretical simulations of the waveforms may be difficult to use and any investigations of impurity species may also be affected. This paper outlines some such interaction effects recorded in tests. There are two different kinds of interactions. One is caused by the space charge, and lasts about several tens of nsec. The other is caused by the PD energy accumulation in and around the previous PD channel. This latter effect is not significant for the first fifty or so (in the conditions here) pulses. However, after hundreds or thousands of pulses, the effect of this interaction becomes obvious and has to be taken into account. >