PLCs in Electrical Substation Automation

Does anyone know the use of PLCs for Utilities Substation Automation ?
Is there any restriction for that ?

Sequence of Events for Relays was a restriction. But I believe it was solved ? Can anyone comment on that.

PLC's for Utility Substations

Rockwell Automation has significant capability for substation automation. The ControlLogix platform allows for SOE, diagnostic I/O, Modular Communications, 3rd Party integration, etc.... I suggest you take a serious look at the technology. Your local RA/Allen-Bradley distributor PLC specialist will be able to lead you in the right direction and demonstrate the capabilities.

Further reading:

ControlLogix SOE
Product Profile
http://www.ab.com/manuals/cl/1756-pp007a-en-e.pdf
User Manual
http://www.ab.com/manuals/cl/1756-um528a-en-p.pdf

regards,

Ben