!Who knows about this technology?!

http://www.drives.com/site/Products.nsf/products/Industrial AC Drives~matrixconverter.html

I was researching again for a drive replacement, and looking for a 7.5HP AC drive 460vac 3ph input with a height of less than 11 inches, among brands we already stock, one of which is Yaskawa.

Are all the drive manufacturers out with these yet?

Is this not revolutionary?


EDIT:
http://www.scribd.com/doc/7478137/A...trix-Converter-for-Adjustable-Speed-AC-Drives

Okie

This is pretty common in medium voltage drives such as powerflex 7000 series but not in low HP ranges like you posted.

The 7000 series use SGCT symmetrical gate commutated thyristor vs IGCT units. That gives pure sinus output and you need no isolation transformer or VFD cable on long runs.

We have a few of the SGCT units at school in the high voltage lab. I also have 7000 series drives at work. Iknew smaller drives were in the works but i did not think it was anywhere near release.

Pretty Cool

Wow, do you know what his means for areas like electric vehicles, and freaking efficiency in general?

How well can they perform as far as regeneration capacity? I need to read the rest of the scrib link...Do you need dynamic braking to stop a high inertia load quickly, or does it just float a slightly taller sine wave right back onto the feeders?

Here is another research paper on it.

http://www.jatit.org/volumes/research-papers/Vol3No2/3vol3.pdf

This link is off the school EE intranet page. It's a little old (2004) but pretty good. I read it a couple of times to get a good understanding http://repository.tamu.edu/bitstream/handle/1969/1048/etd-tamu-2004B-ELEN-Cha-2.pdf?sequence=1

OkiePC said:

Wow, do you know what his means for areas like electric vehicles, and freaking efficiency in general?

How well can they perform as far as regeneration capacity? I need to read the rest of the scrib link...Do you need dynamic braking to stop a high inertia load quickly, or does it just float a slightly taller sine wave right back onto the feeders?

Click to expand...

In medium voltage you do not need a brake because the resistor bank would be huge. There are some big units though. Most medium voltage drives that are Ac to Ac as it is sometimes called have a AFE built in. The smaller hp like the yaskawa link i don't know if it is setup as a afe i would think that would raise the price point too much on a 7.5 hp drive and would take more frame size but it could be done.

Most of the time on a drive that small you just have a afe providing the common dc bus but in this case it would be ac but the idea would be the same.

The technology has been around for some years but getting the materials price point right and handling cooling was the problem AFAIK.

I thought it would be a few more years on smaller drives. It has only been mainstream on medium voltage a couple years.

Another good link compliments of GT http://perweb.firat.edu.tr/personel/yayinlar/fua_569/569_58179.pdf

There must be something that I dont get here.
The difference of this "matrix converter" to a VFD is that there is no DC stage, it is only the input AC voltage that is chopped and fed to the 3 output phases in a clever way.
I dont understand how this can generate "pure sinusoidial output".
The documents posted shows how a very unclean sinus voltage is generated.

A PF7000 is a classical VFD with a DC link.
edit: Look at page 1-2 in this pdf:
http://literature.rockwellautomation.com/idc/groups/literature/documents/td/7000-td002_-en-p.pdf

As to functional differences between matrix converter and a VFD:
I can see that there must be an energy saving because there is one link less in the process.
And it says in one of the papers that regenerative power can be sent right back to the net.
Output voltage is max 86% of the input voltage.

Most VFD's are voltage source drives the PF7000 are current source drives, which means you cannot run them unloaded they must have a load or a dead short on the output connections to run them.
A normal VFD can be run with no load, to prove that the drive works.

Alan

I believe that Reliance used to make a current source drive a few years ago, I have not seen them but was told about them from an old Reliance service engineer.

I can see there is a "DC Link inductor" (*), where I would expect a capacitor.
I guess that is the "current source". And I guess that can result in smoother sinus curves.
*: in the schematics for the PF7000.

But the PF7000 is not a matrix converter anyway. There is no DC Link at all in a matrix converter.

Twenty years ago, Robicon, Reliance, Toshiba, and others made current source drives. These were inherently regenerative and the DC bus voltage varied by output speed command. The input rectifiers were SCR's to get this control. They were bullet-proof but the cost of building them eventually doomed them.

The material on matrix converters is interesting and I don't claim to understand them very well. But, in lots of ways, these remind me of the old LCI drives, that's Load Commutated Inverter. These go way back. Some of the early railroad AC catenary was powered with these devices at 10-20Hz.

I would have to classify these matrix converters as developmental, at best. There are other inverter developments on the horizon, as well. Which, if any, of these will prevail if not at all clear to me today. But, as always, cost will be a huge component in the selection process. I can see myself working and teaching in the drive field another 7-8 years, if health permits. I might miss it all!

I need to read the literature again, but when I first saw this, my first thoughts were that this could lead to the most efficient CVT known to man. I pictured it between two (synchronous?) AC motors acting as a widely variable and constantly variable bi-directional transmission between two rotating energy sources. ONe of them being vehicle drive wheels and the other being anything from Li-Po batteries and a DC inverter or a 50,000 rpm 400lb flywheel, or a Hercules 4-banger driving a Lincoln aternator.

Maybe I am (as often) overzealous, so I need to go back and try to understand whether I have mis perceived the implications of this advancement.