Lower cost higher function: Western moves from PLCs to microprocessor relay-based digital control system

摘要

Western area power administration began deploying programmable logic controller (PLC) control systems in 1996 with a pilot project at the Fort Thompson 230-kV yard (Fort Thompson, South Dakota, U.S.). These initial designs only replaced substation control wiring - no aspect of protection was included in the project. The PLC designs included an industrial computer running a Wonderware InTouch software application as the local operator's monitoring and control system human-machine interface (HMI). After modifications to the original design, the PLC design became the standard and was deployed in 20 substations across Western's service territory.