VFDs with long Cables
VFDs with long Cables
(OP)
I often see this topic come up.
In the early days of VFDs when they were SCR based I saw many installations of several hundred feet and I don't think at that time the motors were "VFD rated"
Are we making progress with the new drives or going backwards?
Just curious thats all.
Regards
Roy
In the early days of VFDs when they were SCR based I saw many installations of several hundred feet and I don't think at that time the motors were "VFD rated"
Are we making progress with the new drives or going backwards?
Just curious thats all.
Regards
Roy





RE: VFDs with long Cables
Faster switching also reduces the losses. Reduced losses means a smaller and less expensive package. Reduced losses also means increased efficiency and lower operating cost for the end user.
When we made the trade, we didn't really realize that we were going to get motor insulation and bearing problems in the deal. By the time the problems were fully recognized, it was too late to go back. In most installations, we have smaller, more efficient, less expensive drives with few problems. Where there are problems, we have an add-on solution that costs a little more, but probably not more than the old designs.
Perhaps multi-level inverters and matrix converters will prove to be a step forward without a half-step backwards.
CJC
http://www.vfdriveinfo.com
RE: VFDs with long Cables
I am not sure about the rules here. So I prefer not to spell out the name of the brand. But you can find them if you google relevant terms. The technique used is sometimes called the 'switch circuit'.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: VFDs with long Cables
Do you have a commercial interest in the company Gunner?
Do they do more than build 0-15kW, 380/400V drives?
RE: VFDs with long Cables
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If we learn from our mistakes I'm getting a great education!
RE: VFDs with long Cables
RE: VFDs with long Cables
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: VFDs with long Cables
Please see if you can find it because I'm quite intrigued by this technology. I spent about 15 mins looking and didn't find it.
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If we learn from our mistakes I'm getting a great education!
RE: VFDs with long Cables
I notice several "improvements". The worst is that "Inverters are everywhere" has been replaced with "Inverters are all over the place". Please disregard those "improvements". Also, pictures that were included in the text have been removed. So, I don't think that it is a good idea to read that text any more.
I think that the best description is in the patent text. Will look for the patent number.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: VFDs with long Cables
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If we learn from our mistakes I'm getting a great education!
RE: VFDs with long Cables
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: VFDs with long Cables
It is a report that I wrote for a Swedish Electric Power Research Institution back in 2002.
It shows how energy is stored in the magnetic field in the output reactor. But it doesn't show very well how the transient-free switching is done.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...