4 Protection Functions and Specifications
D02416R04.00
F-PRO 5100 User Manual
4-19
Thermal Demand
Meter
The thermal demand meter is described in this section. Again, use the step
change power input from Figure 4.17: Step Power Input on page 4-17 as an ex-
ample.
time(minutes)
1.0 PU
0
1
2
3
4
5
0.90 PU
Figure 4.20: Thermal Demand
R
C
Vin
Vout
Figure 4.21: RC Circuit
Figure 4.20: Thermal Demand on page 4-19 shows the thermal model of de-
mand calculation. It acts like a RC circuit as shown in Figure 4.21: RC Circuit
on page 4-19. The output voltage will never reach the final value until the time
goes to infinity, however, we define it in this way it will reach the 90% of the
input when the elapsed time is equal to the Demand Interval (5 minutes for this
example). The thermal demand will reach 99% of the input when the time is
twice of the demand interval, as shown in the table below. The equation for this
response is Vout = Vin*(1-e-t/
), where
is the time constant and it is equal to
2.17147241 minutes. The thermal demand meter data will be calculated and
updated every half-second. The following table shows the response of the ther-
mal demand.
Time (min.)
1
2
3
4
5
6
7
8
9
10
Demand (%
of Input)
36.9
60.1
74.8
84.1
90
93.6
96
97.4
98.4
99
Peak Demand
Quantities
Peak Demand quantities will be derived from the Demand/Trend quantities. A
total of 7 Peak Demand Quantities will be metered:
• 3 Phase Real Power Out (MW)
• 3 Phase Real Power In (MW)
• 3 Phase Reactive Power Out (MVAR)
• 3 Phase Reactive Power In (MVAR)
• A Phase Feeder Current IA (A Pri)
• B Phase Feeder Current IB (A Pri)
Summary of Contents for F-PRO 5100
Page 1: ...F PRO Feeder Protection Relay Model 5100 User Manual Version 4 0 Rev 0...
Page 2: ......
Page 4: ......
Page 8: ......
Page 10: ......
Page 28: ......
Page 94: ......
Page 98: ......
Page 140: ......
Page 146: ......
Page 168: ......
Page 172: ......
Page 174: ......
Page 176: ......
Page 178: ......
Page 190: ......