User-Programmable Inverse-Time Characteristics - ABB RELION REX640 Technical Manual

1MRS759142 C
11.2.1.2
11.2.1.3
REX640
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
>
 
 
GUID-5C2959BE-F341-463F-B203-AB840575BDBB V1 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

GUID-D4289E23-1A3C-4A5D-9A46-A3596F1ECF42 V1 EN
The RD-type is calculated using the formula
I

t s 5 8 1 35 In
[ ] . .
= − ⋅

k I
⋅ >

GUID-7B2D3993-7C18-473C-AA94-B0010E66EA77 V1 EN
General function block features








Section 11
(Equation 355)
(Equation 356)
(Equation 357)
1675