Deregulation, competition and increase in complexity of today’s power networks have resulted in power system stability issues. The specific problems they face today are system wide disturbances, which are not ably covered by existing protection and network control
systems - systems designed decades ago for local area monitoring and control.

Phasors address the problems that have surfaced in most of the major blackouts that have occurred around the world, notably August 2003 Eastern Interconnection Blackout in the U.S., August 16 Western Interconnection Blackout in the U.S., Summer 2003 and 2004 blackouts in Europe and elsewhere.
All these blackout investigations reached some combination of the following conclusions:

• Lack of wide area visibility

• Lack of time-synchronized data

• Inabilty to monitor system dynamics behavior in real time

The Evolution of Phasor Technology

Academic discussion of use of phasor technologies has been taking place since the 60’s.  The use of phasor technology started in the 80’s with the early pioneering work done by Bonneville Power Administration.  During the 80’s, the focus was on research and development of measurement devices – PMUs and PDCs.  During the 90’s, the focus shifted to data networking and addressing the technology issues associated with utilizing multiple PMUs and PDCs.  During the 90’s, the focus moved to utilization of phasors for wide-area monitoring, in the Western Interconnection, especially with the 1996 blackout experience.

With the August 2003 Eastern Interconnection blackout and the emergence of Regional Transmission Organizations (RTOs), the need for technologies for wise-area visualization, real time dynamics monitoring, time-synchronized data became accepted by the industry.  Industry is now focused on phasor-based applications, including:

§      Visualization

§      Monitoring

§      Control/Protection

§      Alarming

§      Disturbance Analysis

§      Forensic Analysis

§      System Dynamics

§      State Estimation