CHAPTER 7: COMMANDS AND TARGETS COMMANDS MENUF60 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL 7-577.1.5 Phasor Measurement Unit one-shotCOMMANDS PMU ONE-SHOTThis feature allows pre-scheduling of a PMU measurement at a specific point in time. It can be used to test for accuracy ofthe PMU and for manual collection of synchronized measurements through the system, as explained here.When enabled, the function continuously compares the present time with the pre-set PMU ONE-SHOT TIME. When the twotimes match, the function compares the present sequence number of the measured synchrophasors with the pre-set PMUONE-SHOT FRACTIONAL SEC. When the two numbers match, the function freezes the synchrophasor actual values and thecorresponding protocol data items for 30 seconds. This allows manual read-out of the synchrophasor values for the pre-set time and pre-set sequence number (via the faceplate display, supported communication protocols such as Modbus orDNP, and the EnerVista UR Setup software).When freezing the actual values, the function also asserts a PMU ONE-SHOT OP FlexLogic operand. This operand can beconfigured to drive an output contact and trigger an external measuring device such as a digital scope with the intent toverify the accuracy of the PMU under test.With reference to the following figure, the PMU one-shot function (when enabled) controls three FlexLogic operands:• The PMU ONE-SHOT EXPIRED operand indicates that the one-shot operation has been executed, and the present time isat least 30 seconds past the scheduled one-shot time• The PMU ONE-SHOT PENDING operand indicates that the one-shot operation is pending; that is, the present time isbefore the scheduled one-shot time• The PMU ONE-SHOT OP operand indicates the one-shot operation and remains asserted for 30 seconds afterwardsWhen the function is disabled, all three operands are de-asserted.The one-shot function applies to all logical PMUs of a given F60 relay.Figure 7-1: PMU one-shot FlexLogic operands COMMANDS PMU ONE-SHOT PMU ONE-SHOTFUNCTION: DisabledRange: Enabled, Disabled PMU ONE-SHOTFRACTIONAL SEC: 0Range: 0 to 99 in steps of 1 PMU ONE-SHOT TIME:2013/06/14 7:58:35Range: YYYY/MM/DD HH:MM:SS
