Allen-Bradley 1404-M4, Руководство пользователя

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Publication 1404-UM001D-EN-E - October 2004
Advanced Features 8-7
IEEE THD and DIN
Both of these total harmonic distortion calculation methods provide a
summary indication of the amount of distortion due to harmonics
present in a system. The standard IEEE definition of harmonic
distortion is “Total Harmonic Distortion (THD)” and is computed for
each channel as follows:
The standard IEC definition of harmonic distortion is the “Distortion
Index (DIN)” and is computed for each channel as follows:
Table 8.2 Harmonic Analysis Functionality
Harmonic data DM
(Avg.) M4
M5 M6 M8 Per
current
channel Per
voltage
channel Avg. of
current
channels Avg. of
voltage
channels
IEEE Total Harmonic Distortion (THD)
• • • • • • • •
IEC Distortion Index (DIN)
• • • • • • • •
Crest Factor
• • • • • • • •
Telephone Interference Factor (TIF)
• • • • • •
K-factor
• • • • • •
IEEE-519 Total Demand Distortion (TDD)
• • •
IEEE 519 Pass / Fail
• • • •
Harmonic distortion, harmonics 1 to 41
• • • •
Harmonic magnitude, harmonics 1 to 41
• • • •
Harmonic distortion, harmonics 42 to 63
• • •
Harmonic magnitude, harmonics 42 to 63
• • •
THD
∞
Σ
n 2 =
H
n
( )
2
H
1
-------------------------
=
Where:
•
H
n
= magnitude of the n
th
harmonic
(n
≤
41 or 63)
•
H
1
= magnitude of fundamental
DIN
∞
Σ
n 2 =
H
n
( )
2
∞
Σ
n 1 =
H
n
( )
2
---------------------
=
Where:
•
H
n
= magnitude of the n
th
harmonic
(n
≤
41 or 63)
•
DIN is equivalent to IEC THD
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