6-18 L30 Line Current Differential System GE Multilin6.3 METERING 6 ACTUAL VALUES6The metered values for real, reactive, and apparent power, as well as power factor, are displayed in this menu. The "SRC1" text is replaced by whatever name was programmed by the user for the associated source (see SETTINGS SYSTEMSETUP SIGNAL SOURCES).When VTs are configured in wye, the L30 calculates power in each phase and three-phase power is measured asS = VA x ÎA + V B x Î B + V C x Î C (EQ 6.1)When VTs are configured in delta, the L30 does not calculate power in each phase and three-phase power is measured asS = VAB x Î A + V CB x ÎC (EQ 6.2)whereS is the apparent powerVA, VB, VC , IA, IB, I C are phase voltage and phase current phasorsVAB and V CB are phase-to-phase voltage phasorsÎ is the conjugate of Ig) FREQUENCY METERINGPATH: ACTUAL VALUES METERING SOURCE SRC 1 FREQUENCYThe metered frequency values are displayed in this menu. The "SRC 1" text will be replaced by whatever name was pro-grammed by the user for the associated source (see SETTINGS SYSTEM SETUP SIGNAL SOURCES).SOURCE FREQUENCY is measured via software-implemented zero-crossing detection of an AC signal. The signal is either aClarke transformation of three-phase voltages or currents, auxiliary voltage, or ground current as per source configuration(see the SYSTEM SETUP POWER SYSTEM settings). The signal used for frequency estimation is low-pass filtered. Thefinal frequency measurement is passed through a validation filter that eliminates false readings due to signal distortions andtransients.If the 87L function is enabled, then dedicated 87L frequency tracking is engaged. In this case, the relay uses the METERING TRACKING FREQUENCY TRACKING FREQUENCY value for all computations, overriding the SOURCE FREQUENCY value.6.3.4 SYNCHROCHECKPATH: ACTUAL VALUES METERING SYNCHROCHECK SYNCHROCHECK 1(4)If a synchrocheck function setting is "Disabled", the corresponding actual values menu item is not displayed.MESSAGE SRC 1 POWER FACTORφa: 1.000MESSAGE SRC 1 POWER FACTORφb: 1.000MESSAGE SRC 1 POWER FACTORφc: 1.000 FREQUENCY SRC 1SRC 1 FREQUENCY:0.00 Hz SYNCHROCHECK 1SYNCHROCHECK 1 DELTAVOLT: 0.000 VMESSAGE SYNCHROCHECK 1 DELTAPHASE: 0.0°MESSAGE SYNCHROCHECK 1 DELTAFREQ: 0.00 Hz
