App-4
IM 253710-01E
Appendix 2 Symbols and Determination of
Measurement Functions
Measurement Functions in the Normal Measurement Mode
u(t)
2
dt
1
T
0
T
u(t)
dt
1
T
0
T
Upk
Urms
Ipk
Irms
Urms
Irms
Irms
2
Q
Irms
2
P
Q
Urms
2
P
S
cos
–1
( )
P
S
u(t)
dt
1
T
0
T
π
2
2
Urms
2
– Udc
2
P
Urms
2
P1 + P2
(
)
2
Urms
Umn
P
S
2
– P
2
Urms
•
Irms
(Umn
•
Imn)
(Udc
•
Idc)
u(t)
•
i(t) dt
1
T
0
T
Urms
Umn
Udc
Uac
U+pk
i(t)
2
dt
1
T
0
T
i(t)
dt
1
T
0
T
i(t)
dt
1
T
0
T
π
2
2
Irms
2
– Idc
2
Irms
Imn
Idc
Iac
Current
I [A]
U-pk
Maximum
Minimum
I+pk
I-pk
Maximum
Minimum
π
Urms
Umn
2
2
Voltage form factor
FfU =
π
Irms
Imn
2
2
Current form factor
FfI =
Voltage crest factor
CfU =
Current crest factor
CfI =
Upk = |U+pk|
or
|U-pk|
which ever is larger
Ipk = |I+pk|
or
|I-pk|
which ever is larger
Impedance of the load circuit
Z [
Ω
]
Measurement Functions
in the Normal
Measurement Mode
Voltage
U [V]
Can combine rms, mn, and dc. See section 10.4.
On products (PZ4000) with firmware version 2.01 or later,
a “-” sign is attached when the phase is leading.
The display format of the phase difference can be switched between
Lead/Lag format and
360
°
format. See section 10.6.
Determination, Equation
fU (FreqU), fI (FreqI) [Hz]
The voltage frequency (
fU
) and current frequency (
fI
) are measured using zero crossing detection.
P1, P2 :
Coefficients as
defined in the
applicable
standard
IEC76-1(1976), IEEE C57.12.90-1993
P
(
1 +
)
Umn – Urms
Umn
IEC76-1(1993)
True rms value
Urms
Rectified mean value
calibrated to the rms
value
Umn
Simple average
Udc
AC component
Uac
Maximum
U+pk
Minimum
U-pk
True rms value
Irms
Rectified mean value
calibrated to the rms
value
Imn
Simple average
Idc
AC component
Iac
Maximum
I+pk
Minimum
I-pk
Voltage form factor FfU
Current form factor FfI
Voltage crest factor CfU
Current crest factor CfI
Active power P [W]
Apparent power S [VA]
Reactive power Q [var]
Power factor
λ
Phase difference
φ
[
°
]
Serial resistance of the load circuit
Rs [
Ω
]
Serial reactance of the load circuit
Xs [
Ω
]
Parallel resistance of the load circuit
Rp [
Ω
] (=1/G)
Parallel reactance of the load circuit
Xp [
Ω
] (=1/B)
Corrected power Pc [W]
Note
•
The period T is determined by the measurement/computation period setting. t = 0 is the start
point and t = T is the end point. For details, see section 10.1.
•
u(t) and i(t) denote the sampled data of the voltage signal and the current signal, respectively.
•
For information on Speed, Torque, Sync, Slip, Pm, motor efficiency, and total efficiency, see chapter 15.
•
The polarity of the reactive power (Q) and the lead (D)/lag (G) of the phase angle (f) are
properly detected when both the voltage and cuent are sinu/ids. Proper detection may not be
possible if the input ratio between the voltage and current differs greatly with respect to the
measurement range or the voltage or current is distorted.
•
Reactive power (Q), power factor (l), phase (f), and inductance (Xs and Xp) are computed
using apparent power (S) that is determined according to the selected computing equation.
