CONTROL ELEMENTS
Analysis of metering errors at UR-2
The remote and local power values are measured with the maximum error of ±1% of reading (at power factors above 0.8).
The digitization (round up) error is 0.2% of full scale, or 0.002 x 2 x 1500 MW = 6 MW. Consequently,
•
Remote power is measured at UR-2 with a worst-case error of ± (1% of reading + 6 MW)
•
Total power is measured at UR-2 with a worst-case error of ± (1% of UR-1 reading + 1% of UR-2 reading + 12 MW)
For example, with a reading of 1020 MW at UR-1 and 800 MW at UR-2, the remote power is measured at UR-2 with the
worst-case error of ±(0.01 x 1020 MW + 6 MW) = ±16.2 MW, or ±1.6%. The reading for remote power at UR-2 is the product
of the digitized value sent from UR-1 and received at UR-2 and the scale factor setting. That is,
Therefore, the reading for the remote power at UR-2 is 1015.7 MW, versus 1020 MW at the point of origin (UR-1).
The total power is measured at UR-2 with the worst-case error of ± (0.01 x 1020 MW + 0.01 x 800 MW + 12 MW) = ±30.2MW,
or ±1.7%. The reading for the total power at UR-2 is the sum of the digitized value sent from UR-1 and received at UR-2 and
the digitized value at UR-2 multiplied by the scaling factor. That is,
Total Power at UR-2
Therefore, the reading for the total power at UR-2 is 1818.7 MW, versus a true total of 1020 MW + 800 MW = 1820 MW.
5.8.14 8-bit switches
5
SETTINGS CONTROL ELEMENTS 8-BIT SWITCHES 8-BIT SWITCH 1(6)
8-BIT
SWITCH 1
This feature allows switching between two input arguments defined by 8 bits each. The bits are specified by FlexLogic
operands. The feature could be viewed as an integrated two-position switch for 8 logic signals.
Typically this element is applied in conjunction with the Digitizer and 8-bit Comparator features.
8BIT SW 1 ARG A0 to 8BIT SW 1 ARG A7
switch. These operands are routed to the output operands if the control input is in the "Off" position.
5-224
Total Power at UR-1
=
round
=
86 11.81 MW
1020 MW
--------------------- -
=
round
1500 MW
11.81 MW
=
86 68
+
8BIT SWITCH 1
FUNCTION: Disabled
8BIT SW 1 ARG A0:
Off
8BIT SW 1 ARG A1:
Off
8BIT SW 1 ARG A7:
Off
8BIT SW 1 ARG B0:
Off
8BIT SW 1 ARG B1:
Off
8BIT SW 1 ARG B7:
Off
8BIT SW 1 CONTROL:
Off
— These settings specify FlexLogic operands that constitute the first (A) input of the
N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
1020 MW
--------------------- -
127
11.81 MW
1500 MW
=
1015.7 MW
800 MW
--------------------- -
127
+
round
127
1500 MW
=
1818.7 MW
Range: Disabled, Enabled
Range: FlexLogic operand
Range: FlexLogic operand
Range: FlexLogic operand
Range: FlexLogic operand
Range: FlexLogic operand
Range: FlexLogic operand
Range: FlexLogic operand
CHAPTER 5: SETTINGS
Eq. 5-23
11.81 MW
Eq. 5-24