I would strongly recommend using a control that can handle the power requirements you need. Even if each control put out the exact same voltage magnitude and frequency, there is no guarantee each control will share 1/2 the motor current. Most likely each phase leg current will be higher in the IGBT or Freewheel diode with the lowest Vsat or forward diode drop in each control. IGBT's don't like to be paralleled anyhow, so you would probably go into thermal runaway on one control. You would be better off using dual AC motors and dual AC controls. Just to make life easy I would take the simple route and use an single AC motor and control with the power requirements you need. Rod P.S. What the heck are you building?
On Thursday, September 26, 2002, at 07:10 AM, Rod Hower wrote: > The problem with parallel controls is that the frequency and voltage > magnitude would have to match up perfectly or the controls would be > working against > each other. > Rod Thanks Rod and Seth, I figured as much for matching the controllers. If their waveforms don't match perfectly there will be problems. I'm considering putting two controllers, with separate battery packs, made by the same company, in parallel onto one motor, also made by the same company. My hope is that this would give twice the motor output (or close to it). Its probably not likely that the two controllers would just act in unison without some kind of matching interface between them, huh? Is there anything that I could do to the juice they're dishing out to get it into sync before it hits the motor? We're talking about a 144V system here. I'm not sure how much interaction I'll be able to get between the two controllers. They'll both be driven by the same throttle control, but I suppose that doesn't guarantee anything. Any idea on how I could test for waveform sync without blowing my motor? Thanks, Matt
