Schweitzer Engineering Laboratories SEL-387E - Page 111

Date Code 20080110 Protection Functions 3-63
SEL-387E Instruction Manual
The figures below are similar to IEEE C37.102 : 1987 IEEE Guide for AC Generator Protection
Figure 4.5.4-1 and Figure 4.5.4-2
.
.01 0.1 1.0 10 100 1000
100
110
120
130
140
24D2P2=118%
24D2D2=6 s
24D2P1=110%
24D2D1=60 s
Time (Minutes)
Transformer Limit Curve
on Gen. Voltage Base
Mfg-Generator
Limit Curve
Volts/Hertz (%)
DWG: M300G043
Figure 3.39: Dual-Level Volts/Hertz Time-Delay Characteristic 24CCS=DD
Relay Characteristic
Time (Minutes)
Generator Manufacturer's
Recommended Protection Curve
Transformer Limit Curve on
Generator Voltage Base
DWG: M300G044
.001 .01 0.1 1.0 10 100
100
110
120
130
140
Volts/Hertz (%)
1000
24D2P2=118%
24D2D2=1.2 s
24IP=108%
Figure 3.40: Composite Inverse/Definite-Time Overexcitation Characteristic, 24CCS=ID