CHAPTER 5: SETTINGS
SYSTEM SETUP
N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
5-175
5
Each Phasor Measurement Unit (PMU) contains five triggering mechanisms to facilitate triggering of the associated PMU
recorder, or cross-triggering of other PMUs in the system. They are
•
Overfrequency and underfrequency
•
Overvoltage and undervoltage
•
Overcurrent
•
Overpower
•
High rate of change of frequency
The pre-configured triggers can be augmented with a user-specified condition built freely using programmable logic of the
relay. 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 five
triggers drive the STAT bits of the data frame to inform the destination of the synchrophasor data regarding the cause of
trigger. The following convention is adopted to drive bits 11, 3, 2, 1, and 0 of the STAT word.
Figure 5-92: STAT bits logic
The trigger reset (drop-off) timer is available for all five triggering functions (FREQ, ROCOF, VOLT, CURR, POWER) in individual
trigger settings under the
TRIGGER DPO TIME
setting. This asserts individual trigger operand and overall
PMU x TRIGGERED
operand with stat bits 3 and 11 for a fixed interval defined by this setting. If it is required that
PMU x TRIGGERED
operand with
stat bits 3 and 11 stay longer than the individual reset timer, then use the
PMU x USER TRIGGER
setting assigned with
appropriate elements and FlexLogic. In short, in case of
USER TRIGGER
, the drop-off time needs to be implemented using
FlexLogic.
5.5.7.12 User triggering
SETTINGS
SYSTEM SETUP
PHASOR MEASUREMENT UNIT
PHASOR MEASUREMENT UNIT 1(6)
PMU 1(6)
TRIGGERING
PMU 1(6) USER TRIGGER
The user trigger allows customized triggering logic to be constructed from FlexLogic. The entire triggering logic is refreshed
every two power system cycles.
5.5.7.13 Frequency triggering
SETTINGS
SYSTEM SETUP
PHASOR MEASUREMENT UNIT
PHASOR MEASUREMENT UNIT 1(6)
PMU 1(6)
TRIGGERING
PMU 1(6) FREQUENCY TRIGGER
PMU 1 USER
TRIGGER
PMU 1 USER TRIGGER:
Off
Range: FlexLogic operand
PMU 1 FREQUENCY
TRIGGER
PMU 1 FREQ TRIGGER
FUNCTION: Disabled
Range: Enabled, Disabled
PMU 1 FREQ TRIGGER
LOW-FREQ: 49.00 Hz
Range: 20.00 to 70.00 Hz in steps of 0.01
PMU 1 FREQ TRIGGER
HIGH-FREQ: 61.00 Hz
Range: 20.00 to 70.00 Hz in steps of 0.01