Driving a big generator with a VFD ??????

Hello everyone,

I need some quick help. I have a Ginlong GL-PM5K generator. Typically this generator will be used to produce power, but we have an upcoming conference and I need the generator to rotate our product. This is a big generator, it weighs in excess of 300lbs and produces 5kw at rated speed. The website is here:

http://www.ginlong.com/wind-turbine-pmg-pma-permanent-magnet-generator-alternator-GL-PMG-5k.htm

Is it possible to drive this generator with a VFD? We don't need to rotate very fast at all, maybe 5rpm tops... I don't know if the rpm requirement complicates matters or makes them easier. We were told by Bardac Corp. that it is possible and ordered an invertec drive that they recommended. It is an IP55. Input is 110v 1phase and output is 220v 3phase with 5.8A. Rated hp is 1.5.

On my lathe I run a 10hp drive and the motor is much smaller, so I am not sure if this drive will do what we need it to do or even if this is possible.

Thanks for any help and input you can provide.

Chris Skarzenski

That VFD is WAAAYYYY too small.

My guess is that drive will fault with an overcurrent trip before the motor spins. The internal resistance is probably WAY too low on those windings for the drive. You'd probably need at least a 3 horse, and it wouldn't hurt to have a bigger drive than that on there. I dunno, it may start, but if you try to spin it too fast, or accelerate it too fast, it's going to cause an overcurrent error. I have no idea how many poles that thing has, or what the frequency is supposed to be, but it's going to have to be set low enough to not cause the drive to puke.

What is the purpose behind trying to use that as a motor???

No, it'll drive it...

If you're running it in an uncoupled state (nothing hooked to it), or even lightly loaded, it'll turn... you'll need to mess with all the running parameters, and might have a tough time making it turn really smooth without buzzing, but it'll spin. For starters, run the accelleration parameters really slow, so it'll come up to speed gradually. As you make adjustments, expect the VFD to 'fault out' often until you get the settings just right.

I see that it's protected by patents... if it's being shipped out of Mainland China, does that mean the Mainline is prepared to respect patents extending from other parts of the world?

If not, I wouldn't expect the product to have a warm reception to the US market...

By the way- this is a permanent magnet generator, not a true AC generator. It is closer in similarity to a huge stepper motor, than an AC induction motor. With a little experimentation, some resistors and some non-polarized electrolytic capacitors, you can probably make the thing spin at low speed simply by applying direct-line AC phasing to two of the three legs, and direct-line AC phasing to the third leg THROUGH the capacitor... the resultant phase shift will 'kick' the motor in one direction, the other two legs will complete the rotation...

An INVERTEK drive?

First one I have seen mentioned...... my boss is also the rep for Invertek in this area....... I have used a couple different Invertek drives... for some very strange purposes.

From the speed and power figures, it seems like it should work, but can't be certain without more info, like how much power you need to rotate whatever you are going to rotate at your trade show or whatever.....

I don't much like the genny..... PM ones leave you with no options for control, so you are stuck with a constant speed system and inverter. Induction wind power is SOOOO much simpler...