Western Electricity Coordinating Council
Joint Synchronized Information Subcommittee
2011 – 2015 Workplan
DRAFT FOR DISCUSSION
September 26, 2011
WECC utilities and RCs are involved in wide-scale deployment of phasor measurement
units and their applications under the Smart Grid Investment Grant (SGIG) projects.
WECC Joint Synchronized Information Subcommittee (JSIS) is taking steps to align its
work plan with the needs of the SGIG projects to fully utilize the benefits of the
investments.
WECC JSIS focus areas include:
1. Analysis of power system dynamic performance (on-going activity by operating
entities)
a. Event analysis and system performance evaluation
b. Power plant performance analysis and model validation
c. Lesson’s learned papers
d. Analysis and studies to support the development of operating procedures
e. Operator training materials
f. Analysis and studies to support the development of synchro-phasor based
controls
2. Engineering applications of synchro-phasor data
a. Data mining and event detection tools
b. Power system dynamic performance baselining
c. Model validation tools
d. PMU placement guidelines
3. Wide-area situational awareness applications
a. Oscillation Detection application
b. Mode Meter application
c. Voltage stability applications
d. Synchro-phasor data conditioning and verification.
4. Synchro-phasor technology
a. Handbook “Introduction to Synchro-phasors”
b. PMU performance requirements and inter-operability
c. Synchro-phasor network communication standards
d. Synchro-phasor network security, availability and reliability
WECC JSIS will prioritize the activities and will work with NERC NASPI and DOE on
the resource plan to adequately support the critical activities.
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I.
Analysis of Power System Operations (under development)
A) Event Analysis
Coordinate with
- WECC OC / Performance WG
WECC JSIS will conduct event analysis as such need develops, and will support event
analysis teams in WECC and NERC.
WECC JSIS will use the synchro-phasor data to maintain the frequency response baseline
in the Western Interconnection:
- Interconnection frequency response at nadir
- Interconnection frequency response at the settling frequency, settling time
- Interconnection frequency response at 20, 30, 60, 90 seconds
- Power pick-up on major transmission paths
WECC JSIS will perform correlation analysis between the frequency response
performance and power system conditions (loading, generation mix, transfers, etc).
WECC JSIS will use the synchro-phasor data to maintain the oscillation baseline in the
Western Interconnection.
WECC JSIS will support the development of the lesson’s learned paper by WECC.
B) Power Plant Performance Analysis
Coordinate with
- WECC Control WG
- WECC Model Validation WG
WECC JSIS will work with WECC MVWG to distribute, support and provide training on
the Power Plant Model Validation (PPMV) application. WECC JSIS will use PPMV
application to produce reports of power plant performances during system events.
WECC JSIS will work with Control WG to develop “benchmark” performances for each
type of generators and will compare the actual/modeled plant performance versus the
benchmark.
C) Lesson’s Learned Papers
WECC JSIS will support the development of the lesson’s learned paper by WECC and
NERC.
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D) Operating Procedures
WECC JSIS will support the development of the operating procedures that use
synchronized wide-area information, including:
- Review study plans
- Review and conduct studies when requested
- Review actual operating data
- Review operating procedures
- Recommend alarm levels and settings
The operating procedures will apply to:
- Phase angle alarms
- Mode meter application
- Oscillation detection application
E) Training Materials
WECC JSIS will help with the development of training materials for system operators on
using the Wide-Area Situational Awareness applications
F) Wide-Area Control Schemes
WECC JSIS will review the development of the wide-area control schemes that use
synchronized wide-area information, including:
- Review study plans
- Review and conduct studies when requested
- Review actual operating data
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II.
Engineering Applications
A) Data Mining and Event Detection Tools
Coordinate with
- WECC OC / Performance WG
- NERC NASPI Planning Implementation Task Team
Vickie VanZandt summarized it well: “We are data rich, information poor.” WISP data
will generate tens of TBs of data every year. There is a need for automatic screening of
the data for disturbances or unusual system conditions.
Objectives
2a. Develop “an engineering
tool” that automatically
detects grid disturbances
and unusual operating
conditions
Tasks
Task 2a:
Develop and implement an “engineering tool” that detects
grid disturbances and unusual system conditions such as:
- system events
o network faults and line outages
o off-nominal frequency events
o fault-induced delayed voltage recovery
events
o forced oscillations
- changes in power plant controls
o frequency response
o voltage controls
o power system stabilizers
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B) Power System Dynamic Performance Baselining
Coordinate with
- WECC OC / Performance WG
- NERC NASPI Planning Implementation Task Team
Baseline (noun) is a self-consistent set of measurements and performance metrics that
can be used as a reference for the evaluation of future observed and anticipated
conditions.
Baselining (verb) is comparing the data characterizing some condition of interest with an
appropriately chosen of baseline measurements. Baselining involves two processes (a)
getting and archiving the baseline and (b) using the baseline.
Getting and archiving the baseline:
• Record system measurements that best indicative of system stress:
– Total generation in an interconnection
• Percent of dispatchable load-following generation
• Percent of variable energy resource generation
– Phasor angles
– Generation clusters
– Power flows on key flowgates
– Reactive power reserves, etc
– Status of critical lines and flowgates
– Status of critical generators
– Simultaneous phasor angles and power flows on different interfaces
(especially bringing power to the same sink)
• Calculate dynamic performance indicators:
– Frequency response performance (pre-disturbance, dip and settling
frequency, time of minimum dip, size of generation event, etc)
– Oscillation performance (frequency, damping, energy, mode shapes)
– Voltage stability and power-angle indicators
• Correlate dynamic performance indicators with measurements
Using the baseline:
• Tracking system performance over time
• Detecting and acting upon acute changes in the system performance
• Comparing observed dynamic performance against the models
Baselining to be done at various levels:
• Interconnection
– Control area (Balancing Authority / Transmission Operator)
• Power Plant
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Availability of a complete set of wide-coverage synchro-phasor data sets is a prerequisite for all tasks below.
Objectives
2B-1 Develop and maintain
seasonal baselines for
phasor angles in an
interconnection
Tasks
Task 2B-1a:
Record phasor angles and develop norms for each
operating season / day of week / on- and off-peak.
Task 2B-1b:
Record phasor angles from seasonal and week ahead SOL
studies. Compare the angles with the norms established
during the baseline. Determine if phasor angles can be
used to back up operating nomograms.
2B-2. Develop and maintain
a frequency response
baseline for Western
Interconnection
Task 2B-2a:
For each qualified system frequency event, record the
following:
 Disturbance size
 include event details (generator breaker trip
vs. turbine trip, simultaneous vs. staggered
trip, other actions such as dynamic braking
or load shedding during the event)
 Pre-disturbance frequency, system frequency dip,
and settling frequency
 save system frequency profile
 On-line generation and generation capacity
 amount of synchronous generation
 amount of non-synchronous generation
A qualified event is the one when the system frequency
either drops below 59.9 Hz or raises above 60.06 Hz.
Task 2B-2b:
Compare observed system frequency performance with
that produced by simulation models and advise modeling
work group.
2B-3. Develop and maintain
a baseline for inter-area
power oscillations in
Western Interconnection
Task 2B-3a:
Based on system studies, identify critical factors that
affect inter-area oscillations, such as:
 Status of critical lines
 Phasor angle separation across the system
 Flows on major flowgates
 Status and generation levels of generation
injections groups
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
Reactive support, etc
Task 2B-3b:
Continuously calculate and archive the following
quantities from wide-area PMU data:
 Inter-area oscillation modes, including their
frequency, estimated damping, energy, and mode
shapes
Correlate damping indicators with the system conditions.
Task 2B-3c:
Compare observed oscillatory performance with the
behavior observed by power system models and advise
modeling work group.
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C) Power System Model Validation Tools
Coordinate with:
- WECC TSS / Modeling and Validation WG
- NERC NASPI Planning Implementation Task Team
Decisions on power system operating limits are based on power system studies. The
studies rely on the accuracy of power system models in predicting system performance
for anticipated disturbances. Periodic system model validation is necessary to ensure that
the power system models are accurate and up to date. Actual disturbances present great
opportunities for model verification and model improvements. The need for a continual
system model validation is recognized in a white paper prepared by NERC Model
Validation Task Force under Transmission Issues Subcommittee in May 2010. The need
for generating unit model validation is addressed by NERC MOD-026-27 standards.
Model validation needs to be performed at various levels:
• Interconnection
– Power Plant
– Load center
– Grid controllers like HVDC, SVC, etc
Objectives
2C-1. Support WECC
MVWG in developing tools
and conducting regular
power plant model
verification studies using
disturbance data
Tasks
Task 2C-1a:
Develop a lesson’s learned paper on using PMUs for
power plant model validation.
Task 2C-1b:
Develop requirements for the grid simulators to have
disturbance playback capabilities in their software
packages
Task 2C-1c: develop automated tools that use disturbance
recordings for power plant model verification
Task 2C-1d: develop processes and tools for managing
data, both model data and disturbance records, for power
plant model validation
Task 2C-1e: develop understanding of the sensitivities of
power plant data and controls with respect to observed
dynamic performance
Task 2C-1f: apply similar methods for validation of load
models and grid controllers
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Task 2C-1g: provide training for use of the tools for
power plant model verification
2C-2. Support WECC
MVWG in conducting
regular system-wide model
verification studies using
disturbance data
Task 2C-2a: put in place systems for disturbance data
collection and for system performance analysis
Task 2C-2b: develop understanding of the sensitivities of
system model data with respect to observed dynamic
phenomena
Task 2C-2c: continue developing tools for system-wide
model validation
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D) PMU Placement Criteria
Coordinate with:
- WECC TSS / Modeling and Validation WG
- NERC NASPI Planning Implementation Task Team
Objectives
3D-1. Review and revise
WECC PMU placement
guideline
Tasks
Task 3D-1a:
Maintain and review WECC PMU Placement Guideline
Task 3D-1b:
Identify substations and signals that are needed for
reliability applications
3D-2. Support the
development of NERC
disturbance monitoring
standards
Task 3D-2a: Review, comment and support the
development of NERC disturbance monitoring standards
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III.
Wide-Area Situational Awareness Applications
Coordinate with:
- WECC OC
- NERC NASPI Operations Implementation Task Team
A) Oscillation Detection Application
Detection of power oscillations is one of the premier applications of the synchro-phasor
technology. There is variety of power oscillations in the system, including:
- inter-area electromechanical power oscillations – energy exchanges between large
groups of generators, usually at 0.2 to 0.7 Hz frequencies in the WECC today
(e.g. COI power oscillations on August 10, 1996 and August 4, 2000)
- local electromechanical oscillations – a generator is oscillating against the
interconnection, usually at 0.7 to 1.5 Hz frequencies (Boundary oscillation)
- control oscillations (PDCI oscillation in January 2008)
- generator torsional oscillations
Usually, the oscillations are limited in the magnitude. The problem is when the
oscillations are growing or sustained at high amplitude. Growing or large oscillations
often result from high system stress, failed/malfunctioning controllers or a resonance
condition. There is a need for an operational application to alarm dispatchers when an
oscillation represents stability risk. Oscillation Detection application would scan dozens
of signals over a wide frequency range for any signs of growing or large oscillations.
Objectives
3A-1. Support development,
deployment, testing and
performance evaluation of
Oscillation Detection
applications
Tasks
Task 3A-1a:
Develop performance requirements for Oscillation
Detection application
Task 3A-1b:
Review capabilities of the available Oscillation Detection
applications
Task 3A-1c:
Develop test procedures and back-test the Oscillation
Detection applications using historic data
Task 3A-1d: review / recommend settings for Oscillation
Detection applications
Task 3A-1e: review performance of Oscillation Detection
applications
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B) Mode Meter Application
Oscillation Detection application described above is “reactive”, it indicates a problem
after an oscillation is developed. The value of the Oscillation Detection application is that
it catches all oscillations up to 30 Hz, including those cause by controller malfunctioning
or failure.
Mode Meter is “predictive.” It estimates damping of power oscillations from ambient
“noise” data. Mode Meter, however, applies only to specific modes of the inter-area
power oscillations.
Objectives
3B-1. Support deployment,
testing and performance
evaluation of Mode Meter
applications
Tasks
Task 3B-1a:
Develop/review performance requirements for Mode
Meter application
Task 3B-1b:
Review capabilities of the available Mode Meter
applications
Task 3B-1c:
Develop test procedures and back-test the Mode Meter
applications using historic and simulated data
Task 3B-1d: review / recommend settings for Mode Meter
application
Task 3B-1e: review performance of Mode Meter
application
Task 3B-1g: perform correlation analysis between Mode
Meter estimates and the power system conditions
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C) Voltage Stability Application
Many transmission paths are voltage stability limited in the West. While there has been
significant amount of research done in developing voltage instability indicators, there is a
need to test and validate them in the production environment.
Objectives
3A-1. Support development,
deployment, testing and
performance evaluation of
Voltage Stability
applications
Tasks
Task 3A-1a:
Review available Voltage Stability applications for
dispatcher situational awareness. Determine the course of
actions, work with DOE and EPRI in framing the research
agenda
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D) Synchro-phasor Data Conditioning and Validation
A production-grade synchro-phasor network is designed to the highest levels of reliability
and cyber security. Yet, the critical real time applications must be designed to tolerate
data dropouts and glitches, and must be capable of recognize corrupted data. A higherlevel data validation is required.
Objectives
3E-1. Develop methods for
on-line validation of
synchro-phasor data
Tasks
Task 3E-1a:
Request NASPI Research Task Team to provide guidance
on methods that can be used for synchro-phasor data
validation. These should include data glitches, data
dropouts, CT-PT failures, stale data, loss of
synchronization, intrusion in the data system, etc.
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IV.
Synchro-phasor Technology
A) Synchro-phasor Handbook
Coordinate with
- NERC NASPI
Several utilities have asked for a PMU Handbook. The most common questions are
related to the There is a need for a common place to answer the
- Why should a utility install a PMU? What does a company get out of installing a
PMU? (This is asking more for a cost-benefit analysis/justification.)
- How much does it cost ? - device, telecom, control center work, are there any endto-end solution providers?
- Does it have to be CIP compliant ?
- Can I upgrade my relays to PMU functionality? Does it have CIP implications?
- What PMU data can be used for ? Where can I get the apps ?
- Where can I get help with a business case ?
- What is the cost comparison between installing a PMU vs a DFR? For the unit
itself, other associated equipment, and typical overall cost (including labor).
- What are the advantages/disadvantages or pros/cons for installing a PMU vs
DFR?
- Where should a PMU be installed? At generation sites? At transmission
substations? At what voltage levels?
- What does it take to install a PMU? In addition to the PMU unit, what other
equipment needs to be installed to make a PMU functional?
- What data are we looking for? What data to record? How much data storage
would be needed?
- Does the PMU data need to be streamed to the control center?
- What are the pros and cons for using a separate PMU unit vs the PMU
functionality in existing relays?
- Is it still worthwhile to install a PMU if there are not enough internal resources to
analyze the data?
- How do you install a PMU?
B) PMU Performance Requirements and Interoperability
Coordinate with
- IEEE
- NASPI Performance and Standards Task Team
WECC JSIS will provide input to IEEE and NASPI on PMU dynamic performance
requirements.
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C) Synchro-phasors Data Network Standards
Coordinate with
- IEEE
- NASPI Performance and Standards Task Team
WECC JSIS will provide input to IEEE and NASPI on PMU dynamic performance
requirements.
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