VFD upgrade

[Jonathan]

Just to be clear, vector control gets rated torque down to low (zero with an encoder) speed - it doesn't increase the torque above rated at low speed, as that would exceed the ratings of the motor. This is important since power is the product of torque and speed, so with a constant torque vs speed characteristic the power is proportional to speed - so you only get rated power at rated speed. Or half rated power at half speed... etc

[paulus.v]

I see that vector control is a good thing to have anyway.

From Wikipedia:

Vector control, also called field-oriented control (FOC) ​was originally developed for high-performance motor applications that are required to operate smoothly over the full speed range, generate full torque at zero speed, and have high dynamic performance including fast acceleration and deceleration.
However, it is becoming increasingly attractive for lower performance applications as well due to FOC's motor size, cost and power consumption reduction superiority.
It is expected that with increasing computational power of the microprocessors it will eventually nearly universally displace single-variable scalar volts-per-Hertz (V/f) control.

[EddyCurrent]

Just to be clear, vector control gets rated torque down to low (zero with an encoder) speed - it doesn't increase the torque above rated at low speed, as that would exceed the ratings of the motor. This is important since power is the product of torque and speed, so with a constant torque vs speed characteristic the power is proportional to speed - so you only get rated power at rated speed. Or half rated power at half speed... etc

Isn't that what I implied ?

[paulus.v]

No one uses the Schneider Altivar 12 with the Chinese spindle? I'm going to buy it and will see if I will manage to get it set up and working in vector mode...

[EddyCurrent]

I think if you need technical support then Schneider is a very reputable company and will provide it.

Just found this, it looks like ABB have looked at high speed operation a bit closer,

"Control program introduction
Application specific firmware for high speed grinding and polishing machines. Spindles can operate up to 1400Hz output frequency in scalar mode and up to 32000rpm in vector mode."

http://search-ext.abb.com/library/Do...&Action=Launch

[EddyCurrent]

I just wanted to update the info regarding the ABB ACS355 vector drive because I think it's a great inverter especially now they have addressed high frequency motors better and I would recommend it with the new alternative firmware for high speed spindle operation. http://www05.abb.com/global/scot/sco...ement_A_A5.pdf
ABB confirmed that the issues I had with the drive have now been addressed with the new alternative firmware.

Issues I had http://www.mycncuk.com/threads/6565-...4303#post54303

ABB reply;

"Our factory are always seeking to improve product features and designs to embrace a wide scope of application areas.
The version of ACS355 you have identified, is one such area. Some of the vector control improvements would have been included in the version you have. Frequency limits have also been extended.
Applications running above 600Hz are subject to special measures ... This is another reason for having a unique supplementary option code for the alternative firmware.
If you have any further applications or require a replacement, this would be what we recommend."

[paulus.v]

Thank you for sharing this useful information.

I already got the Altivar 12. If I had this information before I would have seriously considered buying the ABB ACS355. I hope I'll manage to configure it in vector mode without difficulty.