System Control Centers and Telecommunications

Telecommunications equipment is used to communicate information electronically between the electric system control centers (ESCC) and the several remote terminal units (RTUs). This chapter discusses the equipment used in ESCCs, RTUs, and telecommunications. The basic operation of virtually every electric utility in the United States now relies upon supervisory control and data acquisition (SCADA) systems. SCADA systems have the capability of providing graphical representation of the generation stations, transmission lines, substations, and distribution lines. Energy management systems (EMS) became a major extension from SCADA with the arrival of advanced computer programs and applications. Wide Area Monitoring Systems (WAMS) is a relatively new approach to help maintain and assure system reliability using remote phasor measuring units (PMU) sensors, telecommunications, and phasor data concentrators (PDCs) in centralized monitoring centers. Synchrophasors or PMUs compare voltage and/or current waveforms across the grid. The modernization of the electric power grid, from generation through consumption, is undergoing substantial change.