inductive generator voltage control

[djvadder]

I have put together a 50HP inductive generator using an old squirrel cage (induction) motor. I am using the generator to drive a range of 3 phase pump motors (2 HP to 15 HP) and I am having a hard time regulating the voltage coming from the generator. At 50Hz my voltage is about 420V and needs to be 380. I know that I can use different values of capacitors in delta to regulate the voltage, but the capacitance needs to be different for every motor driven. Does anybody know where to get 460V variable capacitors? Or how to build a reliable one? How about variable transformers?

Thanks,
Joe V