Delta U And Delta I; Dead Line Detection - ABB RELION 650 Series Applications Manual

Section 10
Secondary system supervision
10.1.3.5

Delta U and delta I

Set the operation mode selector
The setting of
DI< 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
for operation of dU/dt and
DU> and DI< will be given according to equation
> =
DU
EQUATION1523 V3 EN-US
ISet
< =
DI
EQUATION1524 V4 EN-US
The voltage thresholds
below the minimum operating voltage that might occur during emergency conditions. A
setting of approximately 70% of
The current threshold
function. A 5...10% lower value is recommended.
10.1.3.6

Dead line detection

The condition for operation of the dead line detection is set by the parameters
current threshold and
Set the
margin of at least 15-20% is recommended. The operate value must however exceed the
maximum charging current of an overhead line, when only one phase is disconnected (mutual
coupling to the other phases).
Set the
safety margin of at least 15% is recommended.
156
DU> should be set high (approximately 60% of UBase ) and the current threshold
ISet
USet
prim
.
100
UBase
prim
.
100
IBase
UPh> is used to identify low voltage condition in the system. Set UPh>
IPh> shall be set lower than the IMinOp for the distance protection
UDLD< for the voltage threshold.
IDLD< with a sufficient margin below the minimum expected load current. A safety
UDLD< with a sufficient margin below the minimum expected operating voltage. A
OpDUDI to On if the delta function shall be in operation.
the primary current for operation of dI/dt, the setting of
prim
90 and equation 91.
UBase is recommended.
1MRK 504 158-UEN A
GUID-02336F26-98C0-419D-8759-45F5F12580DE v7
USet
is the primary voltage
prim
(Equation 90)
(Equation 91)
IDLD< for the
Application manual
M13683-78 v4