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LINE SECTIONALIZING USING A PLC AND ABB PROTECTIVE RELAY
CONCLUSION
As illustrated, the ladder logic is segmented according to the tasks required by the PLC. The tasks are:
•
MSTR Modbus Plus Control
•
XMIT Modbus Control of the Radio Modem Polling
•
Operator Interface (MAGELLIS MMI) Control and Function Key Processing
•
Calculation of Feeder Loading
•
Completion of Line Sectionalizing Routines
•
Subroutines to allow the PLC to easily calculate mathematics in floating point mathematics.
The ABB protective relay becomes a versatile device with the inclusion of common off the shelf
equipment such as PLC's Operator interfaces such as MAGELIS and inexpensive radio modems.
Building systems based upon solid communication protocols such as Modbus Plus (giving fast response
to equipment communicating inside a substation) and Modbus (allowing efficient communication between
devices at remote locations) allows complex systems to be added and engineered incrementally as a
budget permits.
Events occurring within the relay can easily be accessed.
programming language within an Modicon PLC allows for additional automation capability to be added
within a substation at minimal cost and minimal programming capability. It is easy to see why the use of
PLC's and microprocessor relays is more prevalent in today's substation designs.
This program has been used with standard ABB product simulators. It was first presented in a joint
Groupe Schneider and ABB seminar in 1998. Copies of this program may be obtained from ABB at no
charge. It is intended for this program to serve as a guide for using PLC's and ABB IED's in automation
systems. There is no expressed or implied warranty or any implication as to the accuracy of the logic and
the content within.
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The easy to configure
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