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IM WT3001E-51EN
• Harmonic Measurement Function That Indicates the Phase Difference (φ) of
the Voltage and Current between the Input Elements
There are five harmonic measurement functions that express the phase difference (φ).
φUi-Uj, φUi-Uk, φUi-Ii, φUi-Ij, and φUi-Ik
(where i, j, and k are input element numbers)
Explanation is given for the case when the number of installed input elements is 4,
elements 1, 2, and 3 are assigned to wiring unit ΣA using a three-phase, four-wire
system. Here i = 1, j = 2, and k = 3.
In this case, the numeric data of the harmonic measurement functions of phase
difference concerning elements 1, 2, and 3 can be determined as shown below.
• φU1-U2
Phase difference of the fundamental voltage U2(1) of element 2 with respect to
the fundamental voltage U1(1) of element 1.
• φU1-U3
Phase difference of the fundamental voltage U3(1) of element 3 with respect to
the fundamental voltage U1(1) of element 1.
• φU1-I1
Phase difference of the fundamental current I1(1) of element 1 with respect to
the fundamental voltage U1(1) of element 1.
• φU1-I2
Phase difference of the fundamental current I2(1) of element 2 with respect to
the fundamental voltage U1(1) of element 1.
• φU1-I3
Phase difference of the fundamental current I3(1) of element 3 with respect to
the fundamental voltage U1(1) of element 1.
If the wiring pattern is set up so that input elements 1 and 2 are assigned to wiring
unit ΣA using a three-phase, three-wire system and input elements 3 and 4 are
assigned to wiring unit ΣB using a three-phase, three-wire system, the numeric
data below are determined.
• Wiring unit ΣA: φU1-U2, φU1-I1, and φU1-I2
• Wiring unit ΣB: φU3-U4, φU3-I3, and φU3-I4
φU1-U3 and φU1-I3 are not determined.
• Harmonic Measurement Function of Wiring Units ΣA and ΣB
(Σ Functions)
The following 6 types of harmonic measurement functions are available. For details
on the determination of each measurement function, see section 7.9.
Characters or Numbers
Measurement
in Parentheses
function
UΣ( )
IΣ( )
PΣ( )
SΣ( )
QΣ( )
λΣ( )
Yes: Numeric data available
• For measurement functions with parentheses, the value "1" is entered in the
parentheses. This represents the numeric data of the fundamental signal.
7.1 Harmonic Measurement Function
1
Yes
Yes
Yes
Yes
Yes
Yes
1
2
3
4
5
6
7
8
9
10
11
12
13
Index
7-5
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