Re: what vfd to buy for closed loop control of 7.5hp Yaskawa spindle motor?
I really wish the manufactures marketing departments would stick with one standard term describing sensorless vector control, it really confuses the specs. They call it all kinds of things trying to make their system sound better than the other guys.
A full closed loop system implies encoder/resolver or hall sensor feedback to the drive for commutation, commonly found in servo drives/permanent magnet AC motors. Something you are not going to find in most VFDs. Sensorless Vector control basically does the same thing by electrical magic in the VFD processor for induction motors.
For your application SV is just fine, you don't need closed loop vector. I do rigid tapping with mine on the lathe, but I do have an encoder on the spindle and my control supports rigid tapping. I could close the loop on my lathe VFD because I do have the encoder module installed, but I have disabled it because it wasn't working for what I wanted to do. As far as speed control, just the SV control is fine, on both my lathe and mill. I've never enabled rigid tapping on my mill, haven't needed it. When I need to thread holes on the mill, I normally do thread milling.
I haven't read through all of the parameter settings for the Huanyang VFD, but most 200V class (180 to 240V) VFDs can be set to output about 180 to 240 V, my lathe spindle is also 200V and I have my VFD set to output 200V max to match the motor nameplate.
I chose to link to the Huanyang VFDs because they meet your requirements, won't bust the budget, and I have been happy with the performance of the one I bought to run my air compressor. It has been running for about 8 months. On my lathe and mill I use Automation Direct GS3 VFDs, but the largest one they have that is rated for single phase input is 3 HP. The larger ones are 3 phase only.
Jim Dawson
Sandy, Oregon, USA