Re: Build Log: Servo Drive and VFD with vector control
I think that separate controller board and inverter with power supply is the only way to go. I recetly began looking into PMSM control and the differences in motors are too big to use one MCU/power stage combo. On eBay there is plentiful of used servomotors from industrial machines (probably from modernization/retrofit), which are quite cheap and for us hobbyist still good enought. And the difference in DC link bus voltage of inverter stage is huge. The motor I bought has the original driver using 670V DC link, some Fanuc ones use about 100V and so on. Also there is difference for power resistor for dynamic braking and other aspect of design that make me think that ability to differentiate the inverter is only way to go for general purpose driver.
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Re: Build Log: Servo Drive and VFD with vector control
Quote:
Originally Posted by
Erythros
I think that separate controller board and inverter with power supply is the only way to go. I recetly began looking into PMSM control and the differences in motors are too big to use one MCU/power stage combo. On eBay there is plentiful of used servomotors from industrial machines (probably from modernization/retrofit), which are quite cheap and for us hobbyist still good enough.
I tend to agree. Since we're not too concerned about efficiency you can get some way by over-rating the components, which doesn't increase the cost too much, but you soon become limited by the switching frequency (and thus control bandwidth) that can be used.
Quote:
Originally Posted by
Erythros
On eBay there is plentiful of used servomotors from industrial machines (probably from modernization/retrofit), which are quite cheap and for us hobbyist still good enough.
I've been vaguely looking out for one to try, as my driver may not be working well with position control just due to the non idealistic properties of the motor I've been testing with.
Really trying to keep the ball rolling with this project, but my PhD work and related things keep getting in the way as I tend to be spending 9am~8pm in the lab. Still, I have however done some more soldering on a few of the PCBs. Here are a few pictures:
http://www.mycncuk.com/attachment.ph...id=14924&stc=1http://www.mycncuk.com/attachment.ph...id=14925&stc=1
Can anyone spot the mistake in this one...
http://www.mycncuk.com/attachment.ph...id=14926&stc=1
Time to stop now though as it's 1:30am and I don't want to miss the eclipse this morning...
Re: Build Log: Servo Drive and VFD with vector control
I cant see that great on my phone, but is it that component across the pins on the microcontroller?
Great work!
Re: Build Log: Servo Drive and VFD with vector control
Quote:
Originally Posted by
Gotty101
I cant see that great on my phone, but is it that component across the pins on the microcontroller?
Yes that's right - I accidentally connected the core voltage regulation filter pin to Vss instead of the capacitor. Fortunately that pin is only connected to a capacitor, so I'm instead lifting that pin and soldering an 0402 capacitor between it and the adjacent Vss pin. Bit fiddly, but it works ...
I've not found any other mistakes yet.
Re: Build Log: Servo Drive and VFD with vector control
Quote:
Originally Posted by
Jonathan
I've been vaguely looking out for one to try, as my driver may not be working well with position control just due to the non idealistic properties of the motor I've been testing with.
What Voltage motor would you want I have a few Large-ish Parker AC Servo motors.?
Re: Build Log: Servo Drive and VFD with vector control
Quote:
Originally Posted by
JAZZCNC
What Voltage motor would you want I have a few Large-ish Parker AC Servo motors.?
Sounds good. Anything up to around 300V, 15A would be fine. Do you have the part number so I can check?
Re: Build Log: Servo Drive and VFD with vector control
Quote:
Originally Posted by
Jonathan
Sounds good. Anything up to around 300V, 15A would be fine. Do you have the part number so I can check?
Ok will Dig out and let you know but i think it's much higher than 300v but I may have smaller one kicking around.
Re: Build Log: Servo Drive and VFD with vector control
Since joining this site, I have mentioned in a couple of posts that I needed an HF spindle drive inverter (1000hz, not the usual 400hz, and also low voltage - 60volts). I have been trying for several years to get a spare as I knew that my inverter was out of production, and nobody seems able to offer a repair service. I contacted Jonathan who told me that he could configure his new driver to suit my needs, so I ordered two of his new drives. Last week my inverter failed and a quick call to Jon had him burning some midnight oil to finish and set up one of the new drives for me. Thank you Jonathan, I have just installed the new driver and have in fact completed a small job. The spindle runs faultlessly throughout the RPM range and I am very impressed. I am aware that this driver can be configured to perform many more functions than I require, but I am over the moon that I have been able to get an inverter that will drive my spindles. Thanks again jonathan. G.
