WATER-TREE RESISTANCE EVALUATION METHOD, INSULATION DESIGN METHOD, AND ROTARY ELECTRIC MACHINE

摘要

To shorten the duration of a water-tree-phenomenon reproduction test, a water-tree resistance evaluation method is provided with a material selection step (S110) for selecting a candidate insulation material, a test step (S120) for carrying out a water-tree test on a test piece having a plurality of electrode holes formed on a first surface thereof, and a candidate insulation material evaluation step (S130) for evaluating characteristics such as the amount and speed of water treeing. The test step (S120) has a system and condition setting step (S121) for configuring conditions so that the first surface of the test piece is immersed in an application-side aqueous solution and a flat second surface on the reverse side from the first surface is immersed in a ground-side aqueous solution, a voltage application step (S122) for configuring conditions so that a ground-side electrode is grounded and alternating current is applied to an application-side electrode, a measurement step (S123) for measuring the amount of water treeing at each prescribed time interval, and a duration determination step (S124) for determining whether a test duration has exceeded a prescribed duration.