高壓誘導電動機의 絶緣劣化特性 및 診斷技法硏究 = A Study on the Insulation Aging Property and Diagnosis Method of High Voltage Induction Motor

다국어 초록 (Multilingual Abstract)

This paper describes that nondestructive tests were conducted on high voltage induction motors in power plant stations and their insulation condition were assessed, In order to verify insulation condition, AC overpotential test was performed at the stator windings of three high voltage induction motors.
The diagnostic tests were conducted on 308 high-voltage motors. And their insulation conditions were assessed. The result show that aging condition was similar to each other regardless of their location(indoor/outdoor) and insulation capabilities of foreign products were better than those of domestic products.
Although one or two items exceeded the criterion values among the delta tan delta (△tanδ), the rate of AC current increase(△I) and the quantity of maximum partial discharge(Q_max) but real insulation strength was not low.
in order to improve the defect in this criterion, the judgment criterion have to be enhanced. although the test result is bad when the inspection has been carried out, the second nondestructive test, it is estimated that final judgment by AC Hipot test is the effective counter proposal.
In other to verify the diagnosis results by methods of discharge-map and judgement standard of the nondestructive test, three high-voltage motors were judged to be in rewinding after destructive test.
The test result was confirmed that the relationship between the judgement of discharge-map and real insulation capabilities is different. On the other hand, the judgment by standard of the nondestructive test was exact relatively. Therefore, discharge-map is limited in application and judgment methods of the diagnosis results have to be improved continuously.