Application - ABB RELION REX640 Technical Manual

1MRS759142 C
5.8.6
REX640
Technical Manual
Dead line detection should be used only when the voltage
transformers are located on the line side of the circuit breaker.
When the CB_CL_CMD input is activated or the dead line condition is detected, the
SOTF control module becomes active. The reset timer is started when CB_CL_CMD
is inactivated or the dead line condition disappears. Thus, the module becomes
inactive after the set SOTF reset time is exceeded.
When the SOTF control module is active, the Operation mode setting defines the
operation criteria for the detection of a switch-onto-fault condition. The detection can
be based on the external start signals from the distance or overcurrent functions, on the
measured internal voltage and current levels, or on both.
Table 1061: Options for SOTF detection
Operation mode
Start
Current & Voltage
Both
The OPERATE output can be blocked by activating the BLOCK input.

Application

The operation of CVPSOF is generally based on the non-directional distance zone or
the non-directional overcurrent stage. When the feeder-side voltage transformers are
used for providing the polarization quantity for the distance or directional overcurrent
protection, the use of non-directional impedance or current based protection for
starting CVPSOF secures a fast switch-onto-fault tripping in the close-in three-phase
short circuits. The non-directional protection provides a fast fault clearance when the
protection is used for energizing a bus from the feeder with a short circuit fault in it.
Other protection functions, like time delayed zero-sequence overcurrent functions,
can be connected to CVPSOF to increase the dependability of the scheme. The other
main advantage of using CVPSOF is that it typically accelerates the tripping in case
of energizing a feeder onto a fault. Without CVPSOF, this tripping is normally
performed by the normal time-graded protection or alternatively by the time-delayed
local backup protection, for which operating times are considerably longer than with
CVPSOF tripping.
Protection related functions
Description
The OPERATE output is activated immediately
after a signal from the trigger module. This
indicates that the breaker is closed onto fault.
The OPERATE output is activated immediately
after a signal from the SOTF detection module.
This indicates that the breaker is closed onto fault.
This operation mode can be used, for example, if
the non-directional distance zone is not available.
The OPERATE output is activated immediately
after a signal from the trigger or SOTF detection
modules. This indicates that the breaker is closed
onto fault.
Section 5
1129