| Abstract: | More than 30,000 thousand dc motors are used by the Japan Railway group companies alone as traction motors for railway vehicles. Insulation breakdown of armatures is one of the most important problems in traction motors. Therefore, various insulation tests are carried out for each motor in overhaul. The methods for insulation tests were determined more than 30 years ago. As insulating materials and the method to compose these materials have progressed in recent years, it is important to research what kinds of insulation tests are suitable for traction motors. We estimated the effects of various insulation tests by carrying out insulation breakdown tests for more than 150 motors. This paper describes the results of the study. © 1999 Scripta Technica. Electr Eng Jpn, 129(2): 90–97, 1999 |
