User-Programmable Inverse-Time Characteristics - ABB RELION Series Technical Manual

1MRS758755 A
11.2.1.2
11.2.1.3
REC615 and RER615
Technical Manual

User-programmable inverse-time characteristics

The user can define curves by entering parameters into the following standard
formula:
 
 
A
 
t s B k
[ ]
= + ⋅
c
 
I
 
E
 −
 

I
>
 
 
A060641 V3 EN
t[s] Operate time (in seconds)
Curve parameter A
A set
Curve parameter B
B set
Curve parameter C
C set
Curve parameter E
E set
I Measured current
Start value
I> set
Time multiplier
k set
RI and RD-type inverse-time characteristics
The RI-type simulates the behavior of electromechanical relays. The RD-type is an
earth-fault specific characteristic.
The RI-type is calculated using the formula

 k
[ ]
t s
=

I
>
 
0 339 0 236 . .
− ×
I

A060642 V2 EN
The RD-type is calculated using the formula
I

t s [ ] 5 8 1 35 In . .
= − ×

k I
× >

A060643 V2 EN
General function block features



 




Section 11
(Equation 78)
(Equation 79)
(Equation 80)
731