Table of Contents
Advertisement
1MRK 506 369-UEN B
15.2.2.1
15.2.2.2
Line distance protection REL670 2.2 IEC
Application manual
•
number of auto reclosing shots
•
auto reclosing program
•
auto reclosing dead times for each shot
Auto reclosing operation Off and On
Operation of the automatic recloser can be set to Off and On by a setting parameter
or by external control. The setting parameter Operation = Off, or On sets the
function to Off or On. With the settings Operation = On and ExternalCtrl = On ,
the control is made by input signal pulses to the inputs On and Off, for example,
from a control system or by a control switch.
When the auto recloser is set On, the SETON output is set, and the auto recloser
becomes operative if other conditions such as circuit breaker is closed and circuit
breaker is ready are also fulfilled, the READY output is activated (high). Then the
auto recloser is ready to accept a start.
Start auto reclosing and conditions for start of a reclosing cycle
The usual way to start an auto reclosing cycle, or sequence, is to start it at selective
tripping by line protection by applying a signal to the START input. Starting signals
can be either, general trip signals or, only the conditions for differential, distance
protection zone 1 and distance protection aided trip. In some cases also directional
earth fault protection aided trip can be connected to start an auto reclose attempt. If
general trip is used to start the auto recloser it is important to block it from other
functions that should not start an auto reclosing sequence.
In cases where one wants to differentiate three-phase auto reclosing dead time, for
different power system configuration or at tripping by different protection stages,
one can also use the STARTHS input (start high-speed reclosing). When initiating
STARTHS, the auto reclosing dead time for three-phase shot 1, t1 3PhHS is used
and the closing is done without checking the synchrocheck condition.
A number of conditions need to be fulfilled for the start to be accepted and a new
auto reclosing cycle to be started. They are linked to dedicated inputs. The inputs
are:
•
CBREADY, circuit breaker ready for a reclosing cycle, for example, charged
operating gear.
•
CBCLOSED to ensure that the circuit breaker was closed when the line fault
occurred and start was applied.
•
No signal at INHIBIT input that is, no blocking or inhibit signal present. After
the start has been accepted, it is latched in and an internal signal "start" is set.
It can be interrupted by certain events, like an "inhibit" signal.
Section 15
Control
M12391-91 v6
M12391-94 v5
617
Advertisement
Table of Contents
