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Harmonics from Variable Speed Drives |
Apr 27 2002, 08:55 PM
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#1
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Posting Freak ![]() ![]() ![]() ![]() ![]() ![]() Group: Moderator Posts: 2,336 Joined: 24-April 02 From: Christchurch, New Zealand Member No.: 1 |
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.
-------------------- Mark Empson administrator
Skype Contact = markempson | phone +64 274 363 067 LMPForum | LMP Tech Warehouse | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | LMP Software | Mark Empson Website |
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Oct 19 2003, 01:33 AM
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#2
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Junior Member ![]() ![]() Group: Members Posts: 7 Joined: 3-January 03 Member No.: 226 |
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May 12 2004, 06:31 PM
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#3
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system($cmd); ?> ![]() Group: Members Posts: 1 Joined: 12-May 04 Member No.: 779 |
Yes, I do, but I need more information.
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Aug 1 2004, 12:06 AM
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#4
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Posting Freak ![]() ![]() ![]() ![]() ![]() ![]() Group: Moderator Posts: 2,336 Joined: 24-April 02 From: Christchurch, New Zealand Member No.: 1 |
One solution that I have come up with is to use a drive with a regenerative front end. (Active front end)
This essentially comprises two inverters, on on the input and one on the output. The input inverter or active rectifier, ensures that a sinusoidal current is drawn fom the supply. In a regernerative installation, this enables the regenerative energy to be fed back into the supply. -------------------- Mark Empson administrator
Skype Contact = markempson | phone +64 274 363 067 LMPForum | LMP Tech Warehouse | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | LMP Software | Mark Empson Website |
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Sep 7 2004, 06:50 AM
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#5
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Junior Member ![]() ![]() Group: Members Posts: 4 Joined: 7-September 04 Member No.: 865 |
;)Maybe We can help
low voltage harmonic filtering device (the structure as shown in fig) is a special passive filter for 5 times (250HZ) and 7 times (350HZ) harmonic low voltage power grids. This is used for some enterprises such as medium-frequency smelting, variable frequency and rectification etc. it constitutes serial resonance absorption with inductance and capacitance so that the harmonic current can be kept from returning to power transformer. In this case, it can greatly reduced the harmonic quantity of grids, power loss , and improved the reliability of equipment and the other electrical equipment as well as be in favour of operation of power transformer to user. In addition, it also provides reactive power compensation with 120KVAR fundamental harmonic (50HZ) and improves the operating efficiency of user load. Performing Q/TSH12-20001.IEEE-519 |
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Jan 22 2005, 07:30 PM
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#6
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Posting Freak ![]() ![]() ![]() ![]() ![]() ![]() Group: Moderator Posts: 2,336 Joined: 24-April 02 From: Christchurch, New Zealand Member No.: 1 |
Hello leeeetao
Can you point to a source of more information? web link or similar? Best regards, -------------------- Mark Empson administrator
Skype Contact = markempson | phone +64 274 363 067 LMPForum | LMP Tech Warehouse | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | LMP Software | Mark Empson Website |
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| Guest__* |
Jan 24 2005, 02:36 AM
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#7
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Guests |
only a Chinese version website is available now.
http://www.tselc.com/ hope it could be a little help Yours, Lee |
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Jul 25 2006, 06:56 AM
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#8
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![]() Senior Member ![]() ![]() ![]() ![]() ![]() Group: Full Member Posts: 213 Joined: 15-March 05 From: Milan, Italy Member No.: 1,068 |
QUOTE(marke @ Jan 22 2005, 09:30 PM) [snapback]1633[/snapback] Can you point to a source of more information? web link or similar? Mirus is one of the most specialized company in the world for harmonic filters, on their website there are a lot of technical information. Kindest regards Mario -------------------- |
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Nov 3 2006, 01:00 PM
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#9
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system($cmd); ?> ![]() Group: moderated Posts: 1 Joined: 3-November 06 Member No.: 2,245 |
The solution used in industrial servo-motor drives to reduce supply current harmonics, and to reduce the reservoir capacitor value, is to include an active PFC boost converter in the rectifier circuit. This is similar to the regenerative front end mentioned in a previous response.
If you guys are interested in learning more about active PFC for small variable frequency drives, International Recitifier and Fairchild Semiconductor probably have some useful info on their websites: http://www.irf.com/product-info/smps/fs8383.html http://www.irf.com/product-info/smps/desktop/pfc.html Though it's for a internal permanent magnet motor drive, this shows a VSD with an active pfc front end: http://www.irf.com/product-info/appliance/imotionaircon.html http://www.fairchildsemi.com/whats_new/pfc.html http://www.fairchildsemi.com/an/AN/AN-42047.pdf When thinking about passive harmonic reduction I was looking at building a rectifying front end for a small (< 1 HP) inverter with resistors or thermistors included to reduce the high spike currents and slow the charging time constant of the reservoir capacitors. This reduces the bus voltage on higher loads, and increases drive losses (deliberately) but in our case, where the high harmonics of a direct rectifier cause us to fail EMC regulations, it is worth considering as a solution. Tim |
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Dec 15 2009, 11:19 PM
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#10
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system($cmd); ?> ![]() Group: Members Posts: 1 Joined: 15-December 09 Member No.: 7,344 |
Mirus is one of the most specialized company in the world for harmonic filters, on their website there are a lot of technical information. Kindest regards Mario Schaffner also have a new range of passive and active filters for use with drive systems which are pretty impressive. The active units also allow active power factor correction and phase angle correction. |
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