ABB Relion REC670, Applications Manual

Page: 304 / 658

3 0
3 0 100
= ×
I
I PU
IBase
EQUATION2293-ANSI V2 EN-US
(Equation 111)
where:
3I0PU is the maximal zero sequence current during normal operating conditions, plus a margin of
10...20%
IBase
is the base current for the function according to the setting
GlobalBaseSel
13.2.3.5 Delta V and delta I
GUID-02336F26-98C0-419D-8759-45F5F12580DE v7
Set the operation mode selector OpDVDI to Enabled if the delta function shall be in
operation.
The setting of DVPU should be set high (approximately 60% of VBase ) and the current
threshold DIPU low (approximately 10% of IBase ) to avoid unwanted operation due to
normal switching conditions in the network. The delta current and delta voltage
function shall always be used together with either the negative or zero sequence
algorithm. If
VSet
prim
is the primary voltage for operation of dU/dt and ISet
prim
the
primary current for operation of dI/dt, the setting of DVPU and DIPU will be given
according to equation 112 and equation 113 .
DVPU
VSet
VBase
prim
= ⋅ 100
EQUATION1765-ANSI V2 EN-US
(Equation 112)
DIPU
ISet
IBase
prim
= ⋅
100
ANSIEQUATION2385 V2 EN-US
(Equation 113)
The voltage thresholds VPPU is used to identify low voltage condition in the system.
Set VPPU below the minimum operating voltage that might occur during emergency
conditions. A setting of approximately 70% of VBase is recommended.
The current threshold 50P shall be set lower than the IMinOp for the distance
protection function. A 5...10% lower value is recommended.
13.2.3.6 Dead line detection
M13683-78 v4
The condition for operation of the dead line detection is set by the parameters IDLDPU
for the current threshold and UDLD< for the voltage threshold.
Section 13
1MRK 511 401-UUS A
Secondary system supervision
298 Bay control REC670 2.2 ANSI
Application manual