Active filter and cable sizing
Active filter and cable sizing
(OP)
Dear Collegues,
I must size the cable of an active filter.
This cable has to carry a little 50 Hz harmonic but lots of harmonics in the range 150 Hz to 2.5 kHz.
So I can't apply the usual sizing criteria based on the fondamental harmonic and the de-rating factors as indicated in the Red Book and the IEEE 519.
I could apply the heating criteria described in IEC 60287 standard for each harmonic. But it could be a very long job.
Is there a standard (ANSI, IEEE, IEC, BS, ...) concerning this matter?
What criteria do you apply? How do you approach this problem?
Thank you
Alex68
I must size the cable of an active filter.
This cable has to carry a little 50 Hz harmonic but lots of harmonics in the range 150 Hz to 2.5 kHz.
So I can't apply the usual sizing criteria based on the fondamental harmonic and the de-rating factors as indicated in the Red Book and the IEEE 519.
I could apply the heating criteria described in IEC 60287 standard for each harmonic. But it could be a very long job.
Is there a standard (ANSI, IEEE, IEC, BS, ...) concerning this matter?
What criteria do you apply? How do you approach this problem?
Thank you
Alex68






RE: Active filter and cable sizing
The neccessary derating for a cable varies signifcantly with cross section.
RE: Active filter and cable sizing
From experience, I would suggest derating the input cable harmonic current by at least 15%, plus the 2%, assuming the the distance to the supply is within 5m.
RE: Active filter and cable sizing
Some data:
Filter:
Connection voltage is 600V. Rating is 4*900A rms. Harmonic current is mainly 5th but this can change and what we need is a general purpose rating method that can be adjusted to almost what ever combination of harmonic loads the operators dial up on the controller. 50Hz is only on a "what left" basis so if heavy drilling load no 50Hz.
Cable:
3x(1x500) sqmm on cable tray indoors 40degC max temp.
Tinned annealed copper conductor, singlo core, taped, 0.6/1kV R-HF-90 insultaed, HF-90-R inner sheath, tape TN/Copper braid, taped, HF-90-R sheaths. To AS/NZS 4193 W/A.
Any suggestion would be appreciated.
Cheers
Alex68