Synchrophasor
Group 1
Harley, Forrest C.
Odom, Chandler N.
Frye, Elizabeth F.
Blalock, Clifton M.
Beau, Justin R.
Lu, Haoyang
Zhao, Jiecheng
Synchrophasor
Task 1: A Brief History
Forrest C. Harley
Synchrophasor: A Brief History
Synchrophasor (PMU) development began at Virginia Tech with initial
funding provided by the Department of Energy, the National Science
Foundation, and the Electric Power Research Institute. [1]
(source: “Field installation of a Virginia Tech
prototype PMU”, Synchronized Phasor
Measurements ~ A Historical Overview, October
2002) [1]
Synchrophasor: A Brief History
Milestones in the development of the synchrophasor:
• Phasor mathematical description (Steinmetz, 1893) [2]
• Global Positioning System (Easton, Getting, Parkinson, 1973) [3]
• Symmetrical Component Distance Relay (Phadke, 1979)[1]
• First synchrophasor prototype (1988) [1]
• First commercial synchrophasor developed (Macrodyne Co., 1992) [1]
Synchrophasor: Phasor Notation
Phasors
[4]
Synchrophasor: Basic Theory
Analog Input
GPS Receiver
Filtering
Time Sync
A/D
Transmission
Synchrophasor: Basic Theory
• Voltage or current signals are measured at the point of installation. Typical
sample rates are on the order of 48 samples per cycle (2880 samples per
second). [2]
• The signal is filtered using an anti-aliasing filter to circumvent aliasing errors. [5]
• Signals are converted to digital signals via an analog to digital converter.
• Phase-lock oscillator in conjunction with GPS timestamps ensures
synchronized sampling. [2]
• Phasors tagged with time information are stored or are transmitted for
processing.
References
[1] Phadke, A.G. (2002, October 6-10). Synchronized Phasor Measurements ~ A Historical Overview.
Paper presented at Transmission and Distribution Conference and Exhibition 2002: Asia Pacific. doi:
10.1109/TDC.2002.1178427.
<http://ieeexplore.ieee.org.proxy.lib.utk.edu:90/stamp/stamp.jsp?tp=&arnumber=1178427>
[2] “Phasor Measurement Unit” Wikipedia. Web 24 October 2014.
<http://en.wikipedia.org/wiki/Phasor_measurement_unit>
[3] “Global Positioning System” Wikipedia. Web 24 October 2014.
<http://en.wikipedia.org/wiki/Global_Positioning_System>
[4] “Phasor” Wikipedia. Web 24 October 2014. <http://en.wikipedia.org/wiki/Phasor>
[5] Electric Power Research Institute. Phasor Measurement Unit (PMU) Implementation and
Applications. October 2007. Web 24 October 2014.
<http://www.epri.com/abstracts/Pages/ProductAbstract.aspx?ProductId000000000001015511>
Synchrophasor
Task 2: State of the Art Designs
Chandler Odom
System Design
• A PMU provides phasor information in real
time
• Phasor Data Concentrators (PDC) are
designed to synchronize and collect the data
from the PMU
• This data is then transmitted to a regional
monitoring system which is maintained by an
ISO
Schweitzer Engineering Laboratories
• SEL offers a wide variety of synchrophasor
products to fit their customer’s needs
• Prices are competitive
• 1-60 messages per second
• Many different products for various uses
ReLab Software
• Allows for easy monitoring and storage of
PMU and PDC data at a rate of up to 100
frames per second
• The drivers will work with other
company’s PMU or PDC
• High performance, and has multiple PDC
support
GE Multilin
• Offers synchrophasor measurement
integrated with protection relay and a standalone synchrophasor measurement unit
• Secure protection
• High speed inter-relay communications
• Prices are a little more expensive than others
Synchrophasor
Task 3: Benefits and Values
Faith Frye
Syncrhophasor: Benefits
•
•
•
•
Wide-area Monitoring (WAMS)
Real-time Operations
Forensic Analysis
Smart Grid
Syncrhophasor: Wide-area Monitoring
• Synchrophasors allow operators to gain wide-area
visibility across the bulk power system for all
interconnections.
• This allows them to see early evidence of changing
conditions and grid problems.
• They can then diagnose and implement solutions to
protect system reliability.
Syncrhophasor: Real-time Operations
• Phasor measurement units allow operators to see voltage
and current levels in real-time.
• This information can be used for knowing when to
generate power or even transfer power from one area to
another.
Syncrhophasor: Forensic Analysis
• Phasor data are essential for analysis of disturbances and
blackouts.
• This data can be analyzed to determine the sequence of
events and what caused the disturbance.
2003 East Coast Blackout
Syncrhophasor: Smart Grid
• By using phasor data to manage grid operations,
transmission efficiency and utilization could be improved
by increasing line throughput and reducing line losses.
Synchrophasor
Task 3: Concerns and Problems
Clifton McClain Blalock
Concerns and Problems
Synchrophasor sys.(50 samples/sec)
VS
SCADA sys. (4 to 10 samples/sec)
***http://www.nrldc.org/docs/documents/Papers/Challenges_Final_As%20Submitted.pdf
Network Security
• “Security was a major concern during
implementation of the project.”
***http://www.nrldc.org/docs/documents/Papers/Challenges_Final_As%20Submitted.pdf
Other Concerns
• Cost
– “The average price of a synchrophasor unit
amounted to $3,000 per unit in 2013.”
– Does not include cost of the network, labor
and maintaining/operation of the device.
**http://finance.yahoo.com/news/research-markets-synchrophasors-smart-grid
Synchrophasor
Task 4: Challenges
Synchrophasor: Challenges
Challenge
Impact
Approach
Accuracy &
Reliability
Control
New device
Advanced Algorithm
WAMS-based Controller
Price
Quantity, Implement
New device
Optimal topology
Installation
Cost of installation and
maintenance
Non-contact measurement
Synchophasor
Task 5: Applications
Haoyang Lu
Applications
•
•
•
•
•
•
Improvement on state estimation
Power flow analysis
Oscillation detection and control
Voltage stability monitoring and control
Load modeling validation
System restoration and event analysis
PMU & FDR
PMU
FDR
Frequency Disturbance Recorders
• Deployed in the distribution line
 ordinary 120 V outlets
• GPS synchronized
• Single phase measurement
 Voltage amplitude, frequency and phase angle
• FNET - a low-cost, FDR-based wide-area power
system frequency measurement network
 http://fnetpublic.utk.edu/
Sample Event: East Coast Earthquake
The effects of a 1600 MW generator trip caused by the East Coast Earthquake on
8/23/2011. Frequency drops from 60.00 Hz to 59.92 Hz.
Location of Disturbance - Frequency-based
• Basic Principle
 Frequency perturbations travel throughout the grid as
electromechanical waves at measurable speeds
 The TDOA (Time Delay of Arrival) is approximately proportional
to the distance of sensors from disturbance center.
• Using frequency “time delay of arrival” in locating the
source of the power system disturbance
On-line Event Location
Sample Event: East Coast Earthquake
https://www.youtube.com/watch?v=XUN_h-k8kBg&feature=youtu.be
Reference
1. Zhong Z, Xu C, Billian B J, et al. Power system frequency monitoring
network (FNET) implementation[J]. Power Systems, IEEE
Transactions on, 2005, 20(4): 1914-1921.
2. ERPI. Phasor Measurement Unit (PMU) Implementation and
Applications. 2007.
3. Phadke, A.G.; Thorp, J.S.; Nuqui, R.F.; Zhou, M. Recent developments
in state estimation with phasor measurements. Power Systems
Conference and Exposition, 2009. PSCE '09. IEEE/PES , vol., no., pp.1,7,
15-18 March 2009
Synchrophasor
Task 6: Related Research Paper
Jiecheng Zhao
Source
Conventional Problems
• Only detect local fault
• Stand alone decision
Proposed Technique
• PMU network
• Faults identification
Technique
Voltage reduction
min 𝑉1 , 𝑉2 , … 𝑉𝑛
Power flow direction
ΔΦ𝑚𝑚 = Φ𝑚𝑚 − Φ𝑛𝑛
max ΔΦ𝑚𝑚 , ΔΦ𝑚𝑚 … ΔΦ𝑚𝑚
Case & Conclusion
Case & Conclusion
•
•
•
•
Data sharing
One Relay
Unit protection
One decision
References
[1] M. M Eissa, M. E. Masoud, M. Magdy Mohamed
Elanwar, “A novel back up wide area protection technique
for power transmission grids using phasor measurement
unit,” IEEE Trans. Power Del., vol. 25, no. 1, Jan. 2010.
Thank You
Any Questions?