17-10
IM CW240E
Measurement Item
3 Phase 3 Wire 2 Current
Voltage RMS Value
U
1
n
U
2
n
(
Calculated as
U
2
u
3(
t
)
)
U
3
n
(
Calculated as
U
3
u
1(
t
)
u
3(
t
)
)
Current RMS Value
Electric Power
Pn
P
1
n
P
3
n
(
P
3
n
U
2
r
I
3
r
U
2
i
I
3
i
)
Qn
Q
1
n
Q
3
n
(
Q
3
n
U
2
r
I
3
r
U
2
i
I
3
i
)
Reactive Power
*1
Apparent Power
*1
I
1
n
I
2
n
(
Calculated as
12
i 1
(
t
)
i
3(
t
)
)
I
3
n
(
S
1
n
S
3
n
)
2
3
Measurement Item
Wiring
3 Phase 3 Wire 3 Current
3 Phase 4 Wire
Voltage RMS Value
U
1
n
(
Calculated as
U
1
u
1(
t
)
u
2(
t
)
)
U
2
n
(
Calculated as
U
2
u
2(
t
)
u
3(
t
)
)
U
3
n
(
Calculated as
U
3
u
3(
t
)
u
1(
t
)
)
u
n
(
t
):
Phase voltage from hypothetical midpoint
U
1
n
U
2
n
U
3
n
Phase voltage
Current RMS Value
I
1
n
I
2
n
I
3
n
I
4
n
(When using 4 current)
Electric Power
Pn
P
1
n
P
2
n
P
3
n
Reactive Power
*1
Qn
Q
1
n
Q
2
n
Q
3
n
Apparent Power
*1
Sn
S
1
n
S
2
n
S
3
n
By performing FFT operation on the 128 sample data that was taken in, nth order harmonics are
broken down into elements as follows.
nth Order Harmonic Voltage RMS Value
Un
: (
Unr
,
Uni
)
nth Order Harmonic Current RMS Value
Un
: (
Inr
,
Ini
)
n
: order
Unr
,
Inr
: real number elements after FFT operation
Uni
,
Ini
: imaginary number elements after FFT operation
P
1
n
,
P
2
n
,
P
3
n
: active power (each element of the nth order)
Q
1
n
,
Q
2
n
,
Q
3
n
: reactive power (each element of the nth order)
um
(
t
),
um
(
t
)
: vector
RMS Value Phase Angle: phase angle of the nth order harmonic element for the fundamental
wave element of the input signal
Electric Power Value Phase Angle:
phase of the current of the nth order for the voltage of the nth order
*1: Internal operation for use in power factor electric power phase angle and power factor
computation.
17.1 CW 240 Specifications