CHAPTER 5: SETTINGS SYSTEM SETUPL30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 5-1555PMU 1 SEQ CURR SHIFT ANGLE — This setting allows correcting positive and negative-sequence currents for vector groups ofpower transformers located between the PMU current point and the reference node. The setting has the same meaning forcurrents as the PMU 1 SEQ VOLT SHIFT ANGLE setting has for voltages. Normally, the two correcting angles are set identically,except rare applications when the voltage and current measuring points are located at different windings of a powertransformer.5.5.8.11 PMU triggering overviewSETTINGS SYSTEM SETUP PHASOR MEASUREMENT UNIT PHASOR MEASUREMENT UNIT 1 PMU 1TRIGGERINGEach Phasor Measurement Unit (PMU) contains five triggering mechanisms to facilitate triggering of the associated PMUrecorder, or cross-triggering of other PMUs in the system. They are• Overfrequency and underfrequency• Overvoltage and undervoltage• Overcurrent• Overpower• High rate of change of frequencyThe pre-configured triggers can be augmented with a user-specified condition built freely using programmable logic of therelay. The entire triggering logic is refreshed once every two power system cycles.All five triggering functions and the user-definable condition are consolidated (ORed) and connected to the PMU recorder.Each trigger can be programmed to log its operation into the event recorder and to signal its operation via targets. The fivetriggers drive the STAT bits of the data frame to inform the destination of the synchrophasor data regarding the cause oftrigger. The following convention is adopted to drive bits 11, 3, 2, 1, and 0 of the STAT word.Figure 5-76: STAT bits logicThe trigger reset (drop-off) timer is available for all five triggering functions (FREQ, ROCOF, VOLT, CURR, POWER) in individualtrigger settings under the TRIGGER DPO TIME setting. This asserts individual trigger operand and overall PMU x TRIGGEREDoperand with stat bits 3 and 11 for a fixed interval defined by this setting. If it is required that PMU x TRIGGERED operand with PMU 1 TRIGGERING PMU 1 USER TRIGGERSee below PMU 1 FREQUENCY TRIGGERSee page 5-156 PMU 1 VOLTAGE TRIGGERSee page 5-157 PMU 1 CURRENT TRIGGERSee page 5-158 PMU 1 POWER TRIGGERSee page 5-159 PMU 1 df/dt TRIGGERSee page 5-160
