CHAPTER 5: SETTINGS CONTROL ELEMENTSN60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL 5-2155Figure 5-108: Frequency rate of change logic5.8.12 DigitizersSETTINGS CONTROL ELEMENTS DIGITIZERS DIGITIZER 1(5)There are five digitizer elements. The digitizer truncates the input signal to user-specified symmetrical limits and digitizesthe outcome with an eight-bit resolution. The following equations describe the basic operation of the element.Eq. 5-18Eq. 5-19wherex is an input signal specified by the DIGITIZER 1(5) SOURCE settingLIMIT is defined by the DIGITIZER 1(5) LIMIT settinground is an operand that rounds up to the nearest integerN out is an integer output of the digitizer (from –127 to 127)The figure illustrates the output characteristic of the digitizer element. DIGITIZER 1 DIGITIZER 1FUNCTION: DisabledRange: Disabled, Enabled DIGITIZER 1 SOURCE:OffRange: Off, any FlexAnalog parameter DIGITIZER 1LIMIT: 1.000 puRange: 0.050 to 90.000 pu in steps of 0.001| V_1 | > PICKUPFREQ RATE 1 BLOCK:OffRUNFREQ RATE 1 SOURCE:Pos seq voltage (V_1)FREQ RATE 1 FUNCTION:SETTINGSEnabled = 1Pos seq current (I_1)Frequency (F)ANDFREQ RATE 1 OV SUPVPICKUP:SETTINGSETTING| I_1 | >PICKUPRUNFREQ RATE 1 OC SUPVPICKUP:SETTINGF > MIN & F < MAXRUNFREQ RATE 1 MINFREQUENCY:SETTINGSFREQ RATE 1 MAXFREQUENCY:ANDCalculate df/dtRUNdf/dt > PICKUPRUNSETTINGSFREQ RATE 1 PICKUP:FREQ RATE 1 TREND:FLEXLOGIC OPERANDSFREQ RATE 1 DPOFREQ RATE 1 OPFREQ RATE 1 PKPFREQ RATE 1 RESETDELAY:SETTINGSFREQ RATE 1 PICKUPDELAY:t PKPt RST832023A2.CDRx truncatedLIMIT if x LIMIT–<,–LIMIT if x LIMIT>,x otherwise,=N out round x truncatedLIMIT---------------------- 127 =
