ABB RELION 620 Series Technical Manual page 374

Section 4
Protection functions
368
I_A
I_B
Power
I_C
V_A
calculation
V_B
V_C
DISABLE
Blocking
BLOCK
GUID-A6E041B1-7F1D-45C0-A69A-154AF835A9B2 V1 EN
Figure 170: Functional module diagram
Power factor calculation
This module calculates three phase power factor using phase currents and voltages.
The three-phase power is calculated from the fundamental frequency components (DFT)
of the phase-to-earth voltages and phase-to-earth currents.
* *
S U I U I U
= ⋅ + ⋅ +
A A B B C
GUID-A02DBA76-14C0-47AF-A256-F522F727AE35 V1 EN
P = Re( ) S
GUID-1185565F-F85E-4821-9E3F-318F50613E7C V1 EN
P
PF
=
S
GUID-0F36CEFC-CE75-467E-A161-5F6FB9364954 V1 EN
Figure 171 shows the resulting sign of the power factor. This should be consistent with the
settings in the power and energy metering function of the relay.
Level
factor
detector 1
Level
detector 2
logic
*
I
⋅
C
1MAC504801-IB E
Timer1
TRIP
t
PICKUP
Timer2
t
ALARM
(Equation 17)
(Equation 18)
(Equation 19)
620 series ANSI
Technical Manual