9 replies to this topic

[marke]

Anybody got ideas on good techniques and filters for reducing the harmonics produced on the supply by large drives? Lots used in rural areas for irrigation and resultant supply distortion is causing problems.

[marke]

Hi, I am involved in an existing installation with a large pump that shares a supply transformer with two consumers houses. The inverter is a significant load and well exceeds the combined loads of the houses. The transformer is fed by a long overhead 11KV line.

When the pump is running, one house has problems with the harmonics generated by the VFD but the other does not. Both houses are fed directly from the transformer terminals with underground cables.
The inverter is fitted with DC Bus chokes and also with a coupled three phase inductor on the input.
The inverter is rated at about 70% of the transformer rating.
One solution to the problem is to install a second transformer to supply the two houses but that is an expensive option. Is there a cheaper and effective option that is guaranteed to work?? Mark Empson
http://www.lmphotonics.com

[Harry Dampers]

Mark there is a device available that will "plug"onto the front of a standard 6 P drive ....and produce a Harmonic spectrum closer to that of an 18 Pulse .

This device is approx 99% efficient ,does NOT reduce your voltage onto the drive terminals and is NOT a traditional broadband filter .The total THDI is approx 6% onto the Mains.

Whether or not it is cheap enough , I dont know. ......but it works.

[marke]

Hello Harry
Welcome to the forum.
I'd like to see more information on this device (and I'm sure others would too). Can you give a reference as to where we can see / purchase such a device??

Thanks,
Mark.

[Harry Dampers]

Mark , here is some more info on the universal Harmonic filter:


Ø Treats all major harmonics generated
by Variable Speed Drives and other
3-ph rectifier loads (5th, 7th, 11th, 13th …)
Ø Easily applied to input of a single VSD
- No need to phase shift against
other VSD’s
- No need for costly harmonic studies
Ø Will meet IEEE 519 standard for both
current and voltage distortion
Ø Input current distortion < 8% over
entire operating range
Ø Power factor .98 lagging to leading
over the normal operating range
Ø Will not resonate with other power
system components
Ø Will not be overloaded by other line
side harmonic sources
Ø Suppresses overvoltages caused by
capacitor switching and other fast
changing loads
Ø Eliminates need for drive isolation
transformers, AC line reactors and
DC link chokes
Ø Removal of harmonics improves overall
system power factor
Ø Saves energy by reducing upstream
harmonic losses while operating at
>99% efficiency
Ø Reduces DC bus ripple and increases
ride-through capability of the load

[Harry Dampers]

Speedy , the answer is yes but I am not sure of the protocol in this regard.......... how can I let you know without promoting someones product ?

Mark ...help us out here.

[Edited on 28/6/02 by Harry Dampers]

[marke]

This is an information forum and not a sales forum. I see no difficulty in answering questions about sources of supply, however I do have a problem with blatent sales promotions. What is the brand and outlet? I'm sure that there are others wanting to know. This is part of information sharing and learning.

[Harry Dampers]

Mark....and others, I have been informed that these Filters are being sold in Australia by a Perth Comany .......t/p 08 93091864.

My info comes from a collegue that has used them....he passed the tech details around in another offline forum that I participate in (hence the delay in response) ......allegedly there is local manufacture .....and some large Australian customers have field tested and approved them.

I have had no applications for these devices yet ....although I can see that for Mines and industries that Self-Generate their Power , there are heavy energy savings ($$$) to be made.

[marke]

This wouldn't be the Mirus Lineator would it? I believe that Emsby sell this in Australia and the phone number looks like the Emsby number. If this is the unit, it is manufactured by a company Mirus in Canada and you can find them at : Mirus
;e;