Woodward SEG HighPROTEC MRA4, Device Manual

Page: 416 / 510

AR-Protection Module – Automatic Reclosure [ANSI 79]
AR-Protection Module – Automatic Reclosure [ANSI 79]
AR
Module AR is used for auto reclosing of overhead lines.
The start timer must not exceed the supervision timer. Otherwise, a series
of uncontrolled reclosure attempts can be provoked.
Tripping times that are longer exceed the parameterized start time due to
an abort of the AR attempt.
Thus, it has to be ensured by all means that:
Supervision time t-Superv > Start time t-Start > longest tripping time
The AR-module requires a signal »CB
READY
«.
An AR-cycle can be stopped by one of 6 assignable blocking signals.
AR procedure:
Initialization/Activation
The state of the AR changes from the inactive to the active state when parameter »Function = active« is
selected and at least one (authorized) protective function is allocated to the AR and provided that the AR-module
is not being blocked by an active blocking signal.
AR activated
When the AR is activated, this state is called »AR.
ACTIVE
« and is signaled as well.
Supervision time (applies only if the CB is switched on manually)
When position »CB P
OS
O
N
« (
THAT MEANS
CB P
OS
O
N
=
TRUE
and CB P
OS
O
FF
=
FALSE
) is signaled, the AR module
changes into the »AR.
T
-S
UPERV
« state and the supervision timer is started. The supervision time is to prevent that
the AR will be started by a protection function on a faulty line after a manual CB-Switch-ON command. While the
supervision time(r) is running down, no auto reclosure attempt can be started.
AR ready
After expiration of the supervision time, the AR module is ready to switch on the CB after a trip by an AR
authorized protection module.
Starting the AR
An alarm or trip of an AR authorized protection stage (up to 6 start functions) sets the AR module in the
»A
R
.
RUNNING
« state. At the same time, the » start time(r)« is started. An reclosure attempt will only be started, if
the trip command of the AR authorized protection function is given within the set start time/duration. The location
and the resistance of the fault have an direct impact on the tripping delay (Inverse characteristics). Via the start
time you have a influence on whether far remote and high resistance failures should start (only inverse
characteristics) a reclosure attempt or not.
Page 416 EN MRA4 04/09