ABB Relion 670 Series Applications Manual page 171

1MRK 511 407-UUS Rev. J
The setting parameters described below are identical for the two steps (
setting parameters are described only once.
Characteristicn : This parameter gives the type of time delay to be used. The setting can be
Definite time , Inverse Curve A , Inverse Curve B , Prog. inv. curve . The selection is dependent on the
protection application.
OpModen : This parameter describes how many of the three measured voltages should be below
the set level to give operation for step n. The setting can be
most applications, it is sufficient that one phase voltage is low to give operation. If UV2PTUV (27)
shall be insensitive for single phase-to-ground faults,
and transmission networks the undervoltage function is mainly a system supervision function and
3 out of 3 is selected.
Pickupn : Set pickup undervoltage operation value for step n , given as % of the parameter VBase .
The setting is highly dependent on the protection application. It is essential to consider the
minimum voltage at non-faulted situations. Normally, this non-faulted voltage is larger than 90%
of the nominal voltage.
tn : time delay of step n , given in s. This setting is dependent on the protection application. In many
applications the protection function shall not directly trip when there is a short circuit or ground
faults in the system. The time delay must be coordinated to the other short circuit protections.
tResetn : Reset time for step n if definite time delay is used, given in s. The default value is 25 ms.
tnMin : Minimum operation time for inverse time characteristic for step n , given in s. When using
inverse time characteristic for the undervoltage function during very low voltages can give a short
operation time. This might lead to unselective tripping. By setting
time for other protections, such unselective tripping can be avoided.
ResetTypeCrvn : This parameter for inverse time characteristic can be set to Instantaneous , Frozen
time , Linearly decreased . The default setting is Instantaneous .
tIResetn : Reset time for step n if inverse time delay is used, given in s. The default value is 25 ms.
TDn : Time multiplier for inverse time characteristic. This parameter is used for coordination
between different inverse time delayed undervoltage protections.
ACrvn , BCrvn , CCrvn , DCrvn , PCrvn : Parameters to create a programmable under voltage inverse
time characteristic. Description of this can be found in the
CrvSatn : Tuning parameter that is used to compensate for the undesired discontinuity created
when the denominator in the equation for the customer programmable curve is equal to zero. For
more information, see the
IntBlkSeln : This parameter can be set to Disabled , Block of trip , Block all . In case of a low voltage
the undervoltage function can be blocked. This function can be used to prevent function when the
protected object is switched off. If the parameter is set
prevented.
IntBlkStValn : Voltage level under which the blocking is activated set in % of VBase . This setting
must be lower than the setting
that is, about 10%.
tBlkUVn : Time delay to block the undervoltage step n when the voltage level is below IntBlkStValn ,
given in s. It is important that this delay is shorter than the trip time delay of the undervoltage
protection step.
Phasor measurement unit RES670
Application manual
Technical manual .
Pickupn . As switch of shall be detected the setting can be very low,
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n = 1 or 2). Therefore, the
1 out of 3 , 2 out of 3 or 3 out of 3 . In
2 out of 3 can be chosen. In subtransmission
t1Min longer than the operation
Technical manual .
Block of trip or Block all unwanted trip is
Section 9
Voltage protection
165