C-H
I can't speak from hands on experience, but my grandfather was a powermaster for the Pennsylvania Railroad for many years, and electric locomotives are a favorite of mine. I work around steam locomotives every day.
The electric trains around here don't arc much. I think the answer to your question is, brute force is a wonderful thing. By the time you get the power transformered down to something that the rest of the equipment can use, most of the "junk" is filtered out. This is assuming that the trains "over ther" work the same way as the electric trains do over here.
The latest electrics actually convert incoming "juice" into dc, then run it back through converters, to control both the frequency, and the voltage to the motors. This is the same controls that the new deseasels use too. By the time the electric is run through all of that curcuitry, it is cleaned up quite a bit.
I'll root around a bit, I might be able to find a better answer from the museum across the street.
Trainwire
