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I'd like to have 3ph 208 in my house for general use (not a motor). If I run the output of a single phase to 3 phase VFD through inductors or a 1:1 transformer will it smooth the SPWM .output into an accurate sine wave?.

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    \$\begingroup\$ This is unlikely to work well. VFDs are optimised for driving motors which can tolerate the PWM outputs. Usually the only reason for requiring three-phase is to drive three-phase motors. If that is your situation then just put the VFDs on the motors. \$\endgroup\$ – Transistor Sep 27 '19 at 18:08
  • \$\begingroup\$ @Transistor It would mostly be for a 3 phase DC supply. \$\endgroup\$ – user232993 Sep 27 '19 at 19:52
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    \$\begingroup\$ @JonRB A DC supply that runs on 3 phase 208V \$\endgroup\$ – user232993 Sep 27 '19 at 21:49
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    \$\begingroup\$ Changing to a single-phase DC supply should be less expensive than using a VFD. If you have a VFD that you don's need for anything else, you could probably get DC from that or hack it to make a DC supply. If your DC supply has a controlled rectifier, the VFD may not like that as a load. It may not like an uncontrolled rectifier load either. I don't think there is any way for this to avoid being a bad idea. \$\endgroup\$ – Charles Cowie Sep 28 '19 at 17:44
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    \$\begingroup\$ Given that VFD's have to be de-rated for single phase usage given the decreased capability of the rectifiers and capacitors that form their DC rail when fed with only a single phase, perhaps what you really should do is find an oversized DC supply that the manufacturer is willing to de-rate for single phase usage. All you are really doing by throwing in the VFD is moving the problem to the VFD's DC bus - and throwing in additional problems, too. \$\endgroup\$ – Chris Stratton Nov 17 '19 at 0:44
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Singe phase can be converted in to three phase using VFD drive by changing algorithm and adding some filters at output.

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    \$\begingroup\$ That's fairly irrelevant to the actual problem. It's not like the asker is going to go change the firmware. \$\endgroup\$ – Chris Stratton Nov 17 '19 at 0:43

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