I have a really old GE Hy-AC drive system on an American Lathe. The system consists of a rectifying bridge arrangement charging capacitors on a 90VDC bus. Connected to this bus are some DC chopper drives controlling analog servomotors for the machine axes, and another chopper that dissipates excess charge buildup through some power resistors.
I have not had too much trouble locating a source for replacments for the chopper drives themselves, but I have not really found any good replacement for the front end, except at the component level: capacitors, diodes, etc.
Has anyone had experience locating a source for a DC bus charging/discharging converter? I even thought about using a regenerative DC drive and doing away with the resistors and braking chopper device, but I am hesitant how a DC drive designed for use with motors will react to a capacitive load. BTW, this system is fed by a
3.8kVA transformer = 42A @ 90V, but the drives can supposedly deliver up to a 100A punch if needed from the capacitor bank.