Neutral as a CCC

[Carultch]

VFDs with a three phase input rectify the voltage to 6-pulse DC. The produce 6n+/-1 harmonics. So 5th, 7th, 11th, 13th, 17th, 19th etc.

OK, so they systematically avoid producing multiples of 3 for the order of harmonics. And the first composite harmonic is 25.

 

[Besoeker]

OK, so they systematically avoid producing multiples of 3 for the order of harmonics. And the first composite harmonic is 25.

Not sure what you mean by composite harmonic?

The series doesn't stop at 19th.

5
7
11
13
17
19
23
25
29
31
35
37
41
43

 

[Smart $]

Not sure what you mean by composite harmonic?

Just guessing but I'd say the first [lowest] harmonic of the series that is a multiple of a lower harmonic of the series, i.e. the fifth harmonic. Also the lowest non-prime number.

 

[Carultch]

Not sure what you mean by composite harmonic?

The series doesn't stop at 19th.

5
7
11
13
17
19
23
25
29
31
35
37
41
43

25 & 35 would be examples in your list. Any harmonic that is not a prime number. Composite is the opposite of prime, and the numbers 0 & 1 is each special case numbers that are neither.

 

[Besoeker]

25 & 35 would be examples in your list. Any harmonic that is not a prime number. Composite is the opposite of prime, and the numbers 0 & 1 is each special case numbers that are neither.

Thank you for that. It isn't a term I'd come across.