Verification of insulation tests for traction motor

Abstract

As for traction motor for railway vehicle, over fifty thousands DC motors are used only in Japan Railways Companies. Insulation breakdown is one of the biggest problem for traction motor and various kind of insulation tests are carried out for every motors at the time of overhaul. The methods and the way of these insulation tests are determined about thirty years ago or more. Materials of insulation and how to compose these materials have progressed in these days. So it is important to research what kind of insulation test is suited for traction motor.
This time we made a research to estimate various kinds of insulation tests by carrying out dielectric breakdown test for over 150 motors. And this paper describes the result.