Where:
I
2
is negative sequence current expressed in per unit of the rated generator current
t
is operating time in seconds
K
is a constant [s], which depends on generator size and design
Current I2-1>
Operate
time
t1Min
t1Max
(Default= 1000 s)
(Default= 5 s)
K1
IEC09000691-2-en.vsd
IEC09000691 V2 EN
Figure 122:
Inverse time characteristic with t1Min and t1Max
For a detailed description of inverse time characteristic, see chapter
.
The reset time is exponential and is given by the following expression:
ResetTime s
ResetMultip
I
I
K
NS
Start
[ ]
−
=
⋅
2
1
EQUATION2111 V4 EN
(Equation 74)
Where
I
NS
is the measured negative sequence current
I
Start
is the desired start level in pu of rated generator current
ResetMultip
is multiplier of the generator capability constant
K equal to setting K1 and thus defines
reset time of inverse time characteristic
1MRK 502 048-UEN A
Section 8
Current protection
247
Technical manual
Summary of Contents for REG650 ANSI
Page 1: ...Relion 650 series Generator protection REG650 Technical manual ...
Page 2: ......
Page 36: ...30 ...
Page 42: ...36 ...
Page 50: ...44 ...
Page 64: ...58 ...
Page 86: ...80 ...
Page 262: ...256 ...
Page 300: ...294 ...
Page 438: ...432 ...
Page 476: ...470 ...
Page 592: ...586 ...
Page 664: ...658 ...
Page 678: ...672 ...
Page 726: ...720 ...
Page 727: ...721 ...