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Old 04-29-2009, 02:38 PM   #1091 (permalink)
Roger Heuckeroth
EV Converter
Join Date: Mar 2009
Location: Saugerties, NY
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Originally Posted by SteveU View Post
Thanx, that's what I expected. So, assuming rewinding the field is undesirable, we do a buck conversion to produce a low voltage/ high current for the low-z field winding. Since we want a field controller anyway, it comes for ~free. Next question: how bad are the field core AC losses? ie do we need an external choke in series? Probably a good idea for EMC compliance anyway?

... Of course, there are practical limits like the field current must not be too low.

I've heard of people trying this with no success. A controller out of Italy (Zappi I believe) tried to achieve regen by separately controlling the field on a series wound motor. They had a lot of problems. I think it is possible, just not practical, but I would love to be proven wrong. In theory it sounds like a good idea.

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