Substation Automation State of Technology for Southern California Edison

摘要

Southern California Edison (SCE) is a shareholder owned electric utility serving over 50,000 square miles of Southern California with over 800 transmission and distribution stations. Soon after World War II, Edison began automating stations utilizing electromechanical relays. Simultaneously, a limited SCADA (Supervisory Control and Data Acquisition) capability was implemented to remotely control breakers and obtain some telemetry. This early generation SCADA system was informally known as "Supy" within Edison. Supy was a point-to-point communication system utilizing frequency-shift coded signaling. By the 1970s and into '80s, PLCs (Programmable Logic Controllers) and RTUs (Remote Terminal Units) were installed to retire Supy. In the mid 80s and into 90s, Intelligent Electronic Devices (IEDs) appeared along with Local Area Network (LAN) inside station. Edison deployed intelligent relays on a LAN coupled to the SCADA system. This scheme integrated three key functions: protection, re-closing automation, and SCADA.