VFD in a Circuit 1

[IVIathis]

I'm a mechanical engineering intern, but one of my many jobs on a a project I've been given is to design the circuitry for a machine we're designing. I've done a lot of research and think I can handle the majority of the design, but I'm having some trouble grasping how to incorporate a VFD into the circuit. The circuit I'm working on involves a 3-phase motor driven by a single-phase VFD. Supply voltage is 120 V (I can give more info as needed)

Would someone be willing to explain how a VFD is integrated into a simple circuit? I can't find anything specific but simple enough to be much help. Thanks in advance for your time.

 

[itsmoked]

Get the manual for the VFD, or ANY VFD. They're all fairly similar. Near the front of the manual there will be a drawing or two that shows how every feature you could ever want is hooked up to it. Of course you'll only need a few. That will show how to "incorporate it".

As for the power. VFDs take in line power and convert it to DC which they store in a capacitor bank. They then synthesize the 3 phase output from the stored DC. If you run them on only single phase it reduces their capacity. Since you mention 120Vac the VFD you need will have to additionally have a voltage doubler incorporated in its front end. That's only possible with very small drives.. I hope your motor is small.

Keith Cress
kcress -

http://www.flaminsystems.com