- #1
mooliak
- 11
- 0
Hi All,
I have access to a 15kW VFD for little money. I only have single phase 240 vac at home, and need to drive a 10kW motor, 3 phase, 415v. I have been reading that 3 phase input VFDs can be run on single phase, but they must be derated by 50%. This would mean a 20 kW VFD. Also, it is a crude solution, and I am looking at doing it better.
What I am thinking is to rectify the incoming single phase. This, I think, would give me ## sqrt2 * V rms ## ie ## 240 * 1.4 = 336 V ##.
This would have much more ripple than the 3 phase produced by the VFD's 3 phase rectifier, but could be smoothed with appropriate caps. The voltage expected from a 6 pulse 3 phase rectifier would be, I think, ## 1.35 * V rms ## which is ##1.35 * 415 = 560 V dc ##
My plan is to feed my dc onto the dc bus of the VFD so that the output stage won't see any difference from if it had been produced by its own rectifier.
Can I employ a voltage multiplier to double it, and then regulate it down? How much would the internal circuitry of the VFD compensate if I just put the 336 v dc in?
Golden words from those who knows would be greatly appreciated.
I have access to a 15kW VFD for little money. I only have single phase 240 vac at home, and need to drive a 10kW motor, 3 phase, 415v. I have been reading that 3 phase input VFDs can be run on single phase, but they must be derated by 50%. This would mean a 20 kW VFD. Also, it is a crude solution, and I am looking at doing it better.
What I am thinking is to rectify the incoming single phase. This, I think, would give me ## sqrt2 * V rms ## ie ## 240 * 1.4 = 336 V ##.
This would have much more ripple than the 3 phase produced by the VFD's 3 phase rectifier, but could be smoothed with appropriate caps. The voltage expected from a 6 pulse 3 phase rectifier would be, I think, ## 1.35 * V rms ## which is ##1.35 * 415 = 560 V dc ##
My plan is to feed my dc onto the dc bus of the VFD so that the output stage won't see any difference from if it had been produced by its own rectifier.
Can I employ a voltage multiplier to double it, and then regulate it down? How much would the internal circuitry of the VFD compensate if I just put the 336 v dc in?
Golden words from those who knows would be greatly appreciated.