YOKOGAWA WT3002E User Manual page 140

Vector Display Examples
When Displaying Numeric Data
(the size of the signal and the phase difference between signals)
For a 3P4W (three-phase four-wire)
wiring system
• U1(1), U2(1), and U3(1) are common
mode voltages.
• I1(1), I2(1), and I3(1) are line currents.
Size of the peripheral circle (range)
I1(1)
U1(1)
φ1(1),
φU1-I1
φU1-I2
I3(1)
φU1-I3
φ3(1)
U3(1)
φU1-U3
When the vector size is zoomed
Example in which the voltage is zoomed
2 and the current is zoomed 1/2 times
IM WT3001E-51EN
For a 3V3A (three-voltage, three-
current) wiring system
• U1(1), U2(1), and U3(1) are line
voltages.
• I1(1), I2(1), and I3(1) are line
currents.
φU1-U2
U1(1)
φU1-U2
I3(1)
U2(1)
U2(1)
φ2(1)
I2(1)
For a 3P3W (three-phase three-wire)
wiring system
• U1(1), U2(1), and U3(1) are line
voltages.
• I1(1), I2(1), and I3(1) are line currents.
However, U3(1) and I3(1) are not
actually measured for the 3P3W
system. The vectors are displayed
through computation.
• By moving the vectors, U1(1), U2(1), and
U3(1), so that the starting points of vectors
I1(1)
are all at the origin O, the phase
relationship can be observed in the same
fashion as the 3P3W system.For the
relationship between the positions of the
φU3-U1
vectors after moving them, see "Vector
Display of Harmonics" in section 7.1,
U3(1)
"Vector Display of Harmonics." (This
O
instrument does not provide a function for
moving the vectors.)
• The phase difference between the line
φU2-U3
voltages can be determined from the phase
difference measurement functions φU1-U2
I2(1)
and φU1-U3.
φU1 – U2 = This is the measurement
φU2 – U3 = (φU1 – U3) – (φU1 – U2) – 180
φU3 – U1 = – (φU1 – U3)
The value indicating the size of the peripheral circle
(range)
The size of the vector representing the voltage and
current is expanded 2 times and 1/2 times,
respectively. The voltage range and current range
values change to one-half and twice the original
values, respectively.
7.10 Displaying Vectors
function φU1-U2.
7-37
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Index