1MAC309294-MB F Section 7
Measurement functions
RER620 389
Technical Manual
Table 339: Parameters for deadband calculation
Power and energy calculation
The three-phase power is calculated from the phase-to-ground voltages and
phase-to-ground currents. The power measurement function is capable of calculating
complex power based on the fundamental frequency component phasors (DFT).
(Equation 44)
Once the complex apparent power is calculated, P, Q, S and PF are calculated with the
equations:
(Equation 45)
(Equation 46)
(Equation 47)
(Equation 48)
Depending on the unit multiplier selected with Power unit Mult, the calculated power
values are presented in units of kVA/kW/kVAr or in units of MVA/MW/MVAr.
Function Settings Maximum/minimum (=range)
Three-phase current
measurement (IA, IB, IC)
A deadband
40 / 0 (=40xIn)
Three-phase voltage
measurement (VA, VB, VC)
V Deadband
4 / 0 (=4xVn)
Ground current measurement
(IG)
A deadband res
40 / 0 (=40xIn)
Ground voltage measurement
(VG)
V deadband res
4 / 0 (=4xVn)
Phase sequence current
measurement (I1, I2, I0)
Ps Seq A deadband, Ng Seq A
deadband, Zro A deadband
40 / 0 (=40xIn)
Phase sequence voltage
measurement (V1, V2, V0)
Ps Seq V deadband, Ng Seq V
deadband, Zro V deadband
4/0 (=4xVn)
Three-phase power and energy
measurement (P, E)
-
In the three-phase power and energy measurement function, P, E, the
deadband supervision is done separately for apparent power S, with the
pre-set value of fixed 10 percent of the Sn and the power factor PF, with
the pre-set values fixed at 0.10. All the power measurement related values
P, Q, S and PF are reported simultaneously when either one of the S or PF
values exceeds the pre-set limit.
S = ⋅+⋅+⋅(V I V I V I
A
A
B
B
C
C
***
)
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