Allen-Bradley 1404-M4, User Manual

Page: 163 / 356

Publication 1404-UM001D-EN-E - October 2004
Advanced Features 8-13
•
Table A.36 Harmonic Results; Odd Harmonics 23 to 41 (M6 and
M8)
•
Table A.37 Harmonic Results; Even Harmonics 2 to 20 (M6 and
M8)
•
Table A.38 Harmonic Results; Even Harmonics 22 to 40 (M6 and
M8)
•
Table A.48 Harmonic Results; Odd Harmonics 43 to 63 (M8
only)
•
Table A.49 Harmonic Results; Even Harmonics 42 to 62 (M8
only)
Each of these tables consists of 14 floating-point elements containing
the following parameters:
•
Channel: 1 = V1, 2 = I1, 3 = V2, 4 = I2, 5 = V3, 6 = I3, 7 = I4 (no
averages)
•
Type of harmonic data: 0 = per cent harmonic distortion, 1 =
magnitude
•
Nth harmonic: expressed according to the type parameter.
Magnitude type is referenced to the primary side of PTs and CTs.
Range: 0.0 to 999.9 * 10
22
•
FFT iteration: each new FFT calculation (used in the previous
four parameters) increments by one from 0 to 32,767 and rolls
back to 0
In Tables A.36, A.37 and A.38 the first nth harmonic element is
reserved and returns a value of 0.
Sag and Swell
The Powermonitor 3000 M6 and M8 models are is capable of
detecting voltage sags and swells. There are many definitions for sag
and swell. IEEE 1159
1
defines sag as:
“A decrease to between 0.1 and 0.9 pu in rms voltage or current
at the power frequency for durations of 0.5 cycle to 1 minute”.
IEEE 1159
1
defines swell as:
“An increase in rms voltage or current at the power frequency
for durations from 0.5 cycles to 1 minute. Typical values are
1.1-1.8 pu”.
Allen-Bradley HMIs