Phasor Technology 101
Please click on the topic for the details

- Why is phasor technology Important?
- What insights will phasors provide for operation and management of the power system?
- Can SCADA provide the same insights on power system dynamics and wide-area visibility as phasors?
- How does phasor technology compare with SCADA?
- What technologies are critical for cost-effective utilization of phasors?

 
Answers

Question:
Why is phasor technology important?

Answer:
Operation of the power system is based on SCADA and EMS systems that have evolved over the last 50 years. Phasors is the next generation of measurement technology that is needed for the real-time wide area monitoring of the power system.

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 1996 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

  • Inability to monitor system dynamics behavior in real-time.

    Phasor technology addresses these shortcomings


Question:
What insights will phasors provide for operation and management of the power system?

Answer:
Phasors can be considered as the MRI of the power system providing high resolution, time-synchronized data for system-wide grid dynamics visibility, compared to the “x-ray quality” visibility of the traditional SCADA-based systems.

 


Question:
Can SCADA provide the same insights on power system dynamics and wide-area visibility as phasors?

Answer:
No. SCADA was designed for local control area monitoring and management. Power system interconnections and development of regional markets have shifted the focus for grid monitoring and control to much larger geographic footprints and adapting SCADA to meet this emerging need is cost prohibitive. Phasors overcome the limitations of SCADA for wide area, time-synchronized, dynamic, real-time grid monitoring and control.
 


Question:
How does phasor technology compare with SCADA?

Answer:
The table below compares phasor capabilities with SCADA:

ATTRIBUTE

SCADA

PHASOR

Measurement

 Analog

Digital

Resolution

2-4 samples per sec

Up to 60 samples per sec

Observability

Steady State

Dynamic/Transient

Monitoring

Local

Wide-Area

Phase Angle Measurement

No

Yes

Measured Quantity

Magnitude – (RMS) – MW, MVAR

Magnitude (RMS) and phase offset from common reference – MW, MVAR, and Angle Difference


Question:
What technologies are critical for cost effective utilization of phasors?

Answer:
Application of phasors requires integrated use of several key technologies for collection of data, transmission of data, and management of data. Recent advances in computers, network management and sensing technologies make the application of phasors technically and economically feasible

 


 
    Electric Power Group. All rights reserved.

  Terms of Use   Contact Us