2nd Harmonics caused by a three pulse rectifier
2nd Harmonics caused by a three pulse rectifier
(OP)
What remediation techniques are available to manage the 2nd harmonics being injected into the AC supply by a three pulse rectifier for a DC motor? Reportedly, the total harmonics on this service exceeds the IEEE 519 limits. The harmonics are predominantly 2nd, 3rd and 5th. If the load increases as proposed, is it likely that the 2nd harmonic could cause problems in the three phase supply transformer?





RE: 2nd Harmonics caused by a three pulse rectifier
Second harmonic will definitely caus problems in the transformer since it will magnetize unsymmetrical and tends to bring the core more or less into saturation.
Third, fifth and seventh are OK, but not second. No way.
By the wat, is it a three-pulse rectifier? Six pulse is more common in drives.
RE: 2nd Harmonics caused by a three pulse rectifier
RE: 2nd Harmonics caused by a three pulse rectifier
If you really have a three pulse rectifier, then there isn't much to do about it. Except changing it to a six pulse rectifier.
RE: 2nd Harmonics caused by a three pulse rectifier
For 3-pulse rectifier firing only once per cycle per phase the two halves of the current waveform are different (only draws current during one half.
Odd harmonics have that particular type of symmetery. Even harmonics don't.
Can someone remind me what is the name for that type of symmetry?
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RE: 2nd Harmonics caused by a three pulse rectifier
RE: 2nd Harmonics caused by a three pulse rectifier
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RE: 2nd Harmonics caused by a three pulse rectifier
HA! LOL.
That answer might also be "two quadrant" symetry.
RE: 2nd Harmonics caused by a three pulse rectifier
I think the word I was looking for was half-wave symmetry. A waveform with half-wave symmetry has only odd harmonics.
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