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Control hierarchy
It is important that the user understand the meaning of the terms 'control-right' and 'control-
hierarchy' in connection with the functioning of the control and monitoring applications in the
sub-station automation system (SAS). For instance, when we wish to operate a device (such as
a piece of switchgear or others), the system has the device forbidden to operate if the system
is unable to give a 'control-right' for the device using the 'control-hierarchy'. Figure 3.3-1
depicts the control-hierarchy; the control-hierarchy is made of three control-levels, two
selector-switches, and three control-points. Either control command of three control-points is
permitted so that the other commands will be forbidden in the system. On this account, no
collision of control-points exists within the system.
Network level
Selector switch
(43R)
Station level
Selector switch (43BCU‡ )
L
R
Bay level
Control levels
Selector switches
Figure 3.3-1 Control hierarchy and selector switches
‡Note:
The
can be programmed during manufacture using the PLC function before shipment,
but it can also be programmed by the user.
§Note:
The user can implement a hierarchy by programming the PLC. For more
details, see Chapter
Control-point in RCC
Communication
RCC
ON/OFF operation on LCD
Remote (R)
Operation
KEY
Switchgear and others
Control points and positions of selector switches
L|R
key on the IED is used for the 43BCU switch. The
PLC function
- 362 -
Control-point in OWS/EWS
EWS
EWS/OWS
Control-point in LCP
Local (L)
Control-right
(→p. 709).
6F2T0207 (0.01)
OWS
L|R
key
GRE200 (5,6)
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