ABB REL670 2.2 IEC - Page 590

[ ]
p
t
A
s B k
i
C
in
æ ö
ç ÷
ç ÷
= + ×
ç ÷
æ ö
-
ç ÷
ç ÷
>
è ø
è ø
EQUATION13000031 V1 EN-US (Equation 525)
In order to adapt to the previous relay characteristic the above equation can be re-
written in the following way:
[ ]
01
1
1
0
so
s
so
t
K
I
s T
I
I
æ ö
ç ÷
ç ÷
= + ×
ç ÷
æ ö
ç ÷
-
ç ÷
ç ÷
è ø
è ø
EQUATION13000032 V1 EN-US (Equation 526)
Thus if the following rules are followed when multi-purpose overcurrent stage one
is set:
•
in >
= I
S0
= 300A
•
35566
118.55
300
so
A
K
I
= = =
•
01
0.64B T= =
•
0.0C =
•
1.0
p =
•
1.0k =
then exact replica of the existing relay will be achieved. The following table
summarizes all required settings for the multi-purpose function:
Setting Group1
Operation On
CurrentInput MaxPh
IBase 1000
VoltageInput MaxPh
UBase 20.50
OPerHarmRestr Off
I_2ndI_fund 20.0
BlkLevel2nd 5000
EnRestrainCurr Off
RestrCurrInput PosSeq
RestrCurrCoeff 0.00
Table continues on next page
Section 13 1MRK 506 369-UEN B
System protection and control
584 Line distance protection REL670 2.2 IEC
Application manual