Start Sensitivity - ABB REG650 Technical Manual

Section 7
Current protection
7.9.7.1
208
Operate
time
t1Max
(Default= 1000 s)
t1Min
(Default= 5 s)
IEC09000691 V2 EN
Figure 106: Inverse time characteristic with t1Min and t1Max
For a detailed description of inverse time characteristic, see chapter
characteristics".
The reset time is exponential and is given by the following expression:


 ResetMultip
[ ]
=
ResetTime s

 
I
  −
 NS
  
I
Start
EQUATION2111 V2 EN
Where
I is the measured negative sequence current
NS
I is the desired start level in pu of rated generator current
Start
ResetMultip
is multiplier of the generator capability constant
defines reset time of inverse time characteristic

Start sensitivity

The trip start levels Current I2-1> and I2-2> of NS2PTOC are freely settable over
a range of 3 to 500 % of rated generator current IBase. The wide range of start
setting is required in order to be able to protect generators of different types and sizes.
IEC09000691-2-en.vsd



⋅
K 1

2

1

1MRK 502 034-UEN -
K1
Current I2-1>
"Inverse time
(Equation 63)
K equal to setting K 1 and thus
Technical Manual