Electric machines package?

[Allen.Windhorn]

Does anyone have a package for analyzing the performance of
electric machines?  Something like Simpower Systems but not based
on Simulink?  I think that uses iterative methods to deal with
loads and transient conditions, rather than trying to work all of
the problem into one giant differential equation set.  I'm trying
to model the transient behavior of a synchronous generator when a
capacitive load is suddenly applied and it isn't going very well.
I checked Google and the Forge and didn't find anything promising.

Regards,
Allen