
Harmonics from Variable Speed Drives
#1
Posted 27 April 2002 - 08:55 PM
Mark Empson | administrator
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#3
Posted 12 May 2004 - 06:31 PM
#4
Posted 01 August 2004 - 12:06 AM
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 | Power Factor | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | Pressure Transducers | Smart Relay | GSM Control | Mark Empson Website | AuCom | Soft Starters
#5
Posted 07 September 2004 - 06:50 AM
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
#6
Posted 22 January 2005 - 07:30 PM
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 | Power Factor | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | Pressure Transducers | Smart Relay | GSM Control | Mark Empson Website | AuCom | Soft Starters
#7
Guest__*
Posted 24 January 2005 - 02:36 AM
http://www.tselc.com/
hope it could be a little help
Yours,
Lee
#8
Posted 25 July 2006 - 06:56 AM
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
Mario Maggi - Italy - http://www.evlist.it - https://www.axu.it
#9
Posted 03 November 2006 - 01:00 PM
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/p...mps/fs8383.html
http://www.irf.com/p...esktop/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/p...tionaircon.html
http://www.fairchild...ts_new/pfc.html
http://www.fairchild...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
#10
Posted 15 December 2009 - 11:19 PM
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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