Advanced EMS applications using synchrophasor systems for grid operation

The 10^th anniversary of the 2003 North-East blackout reminds us the challenges faced and solutions proposed. Several converging technologies are reaching control center operations. Synchronized phasor measurements enable readings of voltages and currents across the power system and provide a more accurate state estimation than the existing Energy Management System (EMS). A synchrophasor system covering a large footprint coupled with fast sampling rates may be best served by a distributed architecture to process data for new advanced algorithms and for historical analysis. The architecture is divided into three levels for data management, functional analysis, and interface to an existing EMS. The present architecture is summarized as local substation data concentrators (PDCs) and control center PDCs that are connected to the existing EMS. Implementation experiences with the execution of state estimation at substation level, communication level, as well as the EMS level by PG&E are presented to demonstrate EMS evolution as part of technological developments.