Overcurrent and Distance Relays - SIPROTEC

Overcurrent and Distance Relays
4
7SJ511 Numerical overcurrent–time protection relay (Version V3)
US Curves
The following inverse–time characteristics
have been adapted to the requirements
of the US market.
The US–version has a ”1” in the 11th
place of the order number.
t � � A
(��� p ) N –1
� B� � D
t tripping time
�p current setting
A, B, N parameters
� �–Squared–T Curve (Fig. 7)
t �
50.7 D � 10.14
(��� p ) 2
t tripping time
�p current setting
D time dial setting
100
70
t [s]
50
20
10
7
5
2
1
0.7
0.5
0.2
0.1
0.07
0.05
0.02
0.01 1 2 3 5 7 10 20
�/�p
D = 10
D = 7
D = 5
D = 3.2
D = 1.6
D = 1
D = 0.5
D = 0.2
D = 0.1
D = 0.05
Fig. 7
Tripping time characteristic, �–squared–T curve
Curve type A B N
Inverse 8.9341 0.17966 2.0938
Short inverse 0.2663 0.03393 1.2969
Long inverse 5.6143 2.18592 1.0000
Moderately inverse 0.054196 0.09328 0.0200
Very inverse 19.138 0.48258 2.0000
Extremely inverse 28.2785 0.12173 2.0000
Definite inverse 0.4797 0.21359 1.5625
100
70
t [s]
50
20
10
7
5
2
1
0.7
0.5
0.2
0.1
0.07
0.05
0.02
0.01 D = 0.05
1 2 3 5 7 10 20
�/�p
Fig. 8
Tripping time characteristic, inverse
D = 10
D = 7
D = 5
D = 3.2
D = 1.6
D = 1
D = 0.5
D = 0.2
D = 0.1
100
70
t [s]
50
20
10
7
5
2
1
0.7
0.5
0.2
0.1
0.07
0.05
0.02
0.01 1 2 3 5 7 10 20
�/�p
D = 10
D = 7
D = 5
D = 3.2
D = 1.6
D = 1
D = 0.5
D = 0.2
D = 0.1
D = 0.05
Fig. 9
Tripping time characteristic, moderately inverse
Siemens LSA 2.1.3 . March 1997