6-16 B30 Bus Differential System GE Multilin6.3 METERING 6 ACTUAL VALUES6f) FREQUENCYPATH: 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.6.3.4 TRACKING FREQUENCYPATH: ACTUAL VALUES METERING TRACKING FREQUENCYThe tracking frequency is displayed here. The frequency is tracked based on the selection of the reference source with theFREQUENCY AND PHASE REFERENCE setting in the SETTINGS SYSTEM SETUP POWER SYSTEM menu. Refer to thePower System section of chapter 5 for additional details.6.3.5 FLEXELEMENTSPATH: ACTUAL VALUES METERING FLEXELEMENTS FLEXELEMENT 1(8)The operating signals for the FlexElements are displayed in pu values using the following definitions of the base units. FREQUENCY SRC 1SRC 1 FREQUENCY:0.00 Hz TRACKING FREQUENCYTRACKING FREQUENCY:60.00 Hz FLEXELEMENT 1FLEXELEMENT 1OpSig: 0.000 puTable 6–2: FLEXELEMENT BASE UNITSBUS DIFFERENTIALRESTRAINING CURRENT(Bus Diff Mag)IBASE = maximum primary RMS value of the +IN and –IN inputs(CT primary for source currents, and bus reference primary current for bus differential currents)BUS DIFFERENTIALRESTRAINING CURRENT(Bus Rest Mag)IBASE = maximum primary RMS value of the +IN and – IN inputs(CT primary for source currents, and bus reference primary current for bus differential currents)dcmA BASE = maximum value of the DCMA INPUT MAX setting for the two transducers configuredunder the +IN and –IN inputs.FREQUENCY fBASE = 1 HzPHASE ANGLE BASE = 360 degrees (see the UR angle referencing convention)POWER FACTOR PF BASE = 1.00RTDs BASE = 100°CSOURCE CURRENT I BASE = maximum nominal primary RMS value of the +IN and –IN inputsSOURCE POWER PBASE = maximum value of V BASE IBASE for the +IN and –IN inputsSOURCE VOLTAGE VBASE = maximum nominal primary RMS value of the +IN and –IN inputs
