17-2
IM 253710-01E
17.4 Measurement Function (Measurement Item)
Measurement function in the normal measurement mode
Measurement functions that are determined for each element (power measurement
module).
(For details related to the determination of and the equations of measurement
functions, see “Appendix 2.”)
Item
Symbol and Meaning
Voltage (V)
Urms : true rms value, Umn : rectified mean value calibrated to the rms value, Udc : simple average,
Uac : AC component
Current (A)
Irms : true rms value, Imn : rectified mean value calibrated to the rms value, Idc : simple average,
Iac : AC component
Active power (W)
P
Apparent power (VA)
S
Reactive power(var)
Q
Power factor
λ
Phase difference (
°
)
φ
Frequency (Hz)
fU : voltage frequency, fI : current frequency
Voltage max. and min. (V) U+pk : Voltage maximum, U-pk : Voltage minimum
Current max. and min. (A) I+pk : Current maximum, I-pk : Current minimum
Crest factor
CfU : Voltage crest factor, CfI : Current crest factor
Form factor
FfU : Voltage form factor, FfI : Current form factor
Impedance (
Ω
) of the load Z
circuit
Resistance and reactance Rs : Resistance of the load circuit that has a resistor R, inductor L, and capacitor C connected in series
(
Ω
) of the load circuit
Xs : Reactance of the load circuit that has a resistor R, inductor L, and capacitor C connected in series
Rp : Resistance of the load circuit that has a R, L, and C connected in parallel
Xp : Reactance of the load circuit that has a R, L, and C connected in parallel
Corrected Power (W)
Pc
(Applicable standard IEC76-1(1976), IEEE C57.12.90-1993, IEC76-1(1993))
Measurement functions (
Σ
functions) that are determined for each selected wiring
method (A, B)
(For details related to the determination of and the equations of
Σ
functions, see
“Appendix 2.”)
Item
Symbol and Meaning
Voltage (V)
Urms
Σ
: true rms value, Umn
Σ
: rectified mean value calibrated to the rms value, Udc
Σ
: simple
average, Uac
Σ
: AC component
Current (A)
Irms
Σ
: true rms value, Imn
Σ
: rectified mean value calibrated to the rms value, Idc
Σ
: simple
average, Iac
Σ
: AC component
Active power (W)
P
Σ
Apparent power (VA)
S
Σ
Reactive power (var)
Q
Σ
Power factor
λΣ
Phase difference(
°
)
φΣ
Impedance (
Ω
) of the load Z
Σ
circuit
Resistance and reactance Rs
Σ
: Resistance of the load circuit that has a resistor R, inductor L, and capacitor C connected in series
(
Ω
) of the load circuit
Xs
Σ
: Reactance of the load circuit that has a resistor R, inductor L, and capacitor C connected in series
Rp
Σ
: Resistance of the load circuit that has a R, L, and C connected in parallel
Xp
Σ
: Reactance of the load circuit that has a R, L, and C connected in parallel
Corrected Power (W)
Pc
Σ
(Applicable standard IEC76-1(1976), IEEE C57.12.90-1993, IEC76-1(1993))
Efficiency 1
η
: Efficiency of wiring B with respect to wiring A
Efficiency 2
1/
η
: Efficiency of wiring A with respect to wiring B