ABB RED650 Applications Manual

a This factor depends on the design of the protection function and can be a
function of the primary DC time constant of the close-in fault current.
k This factor depends on the design of the protection function and can be a
function of the primary DC time constant of the fault current for a fault at the set
reach of zone 1.
The a- and k-factors have the following values for the different types of distance
function:
High speed distance: (ZMFPDIS and ZMFCPDIS)
Quadrilateral characteristic:
a = 1 for primary time constant Tp £ 400 ms
k = 3 for primary time constant Tp £ 200 ms
Mho characteristic:
a = 2 for primary time constant Tp £ 400 ms (For a = 1 the delay in operation
due to saturation is still under 1.5 cycles)
k = 3 for primary time constant Tp £ 200 ms
Quadrilateral distance: (ZMQPDIS, ZMQAPDIS and ZMCPDIS, ZMCAPDIS and
ZMMPDIS, ZMMAPDIS)
a = 1 for primary time constant Tp £ 100 ms
a = 3 for primary time constant Tp > 100 and £ 400 ms
k = 4 for primary time constant Tp £ 50 ms
k = 5 for primary time constant Tp > 50 and £ 150 ms
Mho distance: (ZMHPDIS)
a = 1 for primary time constant Tp £ 100 ms
a = 3 for primary time constant Tp > 100 and £ 400 ms
k = 4 for primary time constant Tp £ 40 ms
k = 5 for primary time constant Tp > 40 and £ 150 ms
22.1.6.3 Breaker failure protection
M11621-3 v5
The CTs must have a rated equivalent limiting secondary e.m.f. E
al
that is larger
than or equal to the required rated equivalent limiting secondary e.m.f. E
alreq
below:
sr
R
al alreq op ct L
2
pr
r
I
S
E E 5 I R R
I
I
æ ö
³ = × × × + +
ç ÷
è ø
EQUATION1380 V2 EN-US (Equation 138)
where:
I
op
The primary operate value (A)
I
pr
The rated primary CT current (A)
I
sr
The rated secondary CT current (A)
I
r
The rated current of the protection IED (A)
R
ct
The secondary resistance of the CT (W)
R
L
The resistance of the secondary cable and additional load (W). The loop resistance
containing the phase and neutral wires, must be used for faults in solidly earthed systems.
The resistance of a single secondary wire should be used for faults in high impedance
earthed systems.
S
R
The burden of an IED current input channel (VA). S
R
=0.020 VA/channel for I
r
=1 A and
S
R
=0.150 VA/channel for I
r
=5 A
Section 22 1MRK 505 393-UEN B
Requirements
430 Line differential protection RED650 2.2 IEC
Application manual

ABB RED650 Specifications

General

Brand	ABB
Model	RED650
Category	Protection Device
Language	English