Technical Studies Subcommittee (TSS) Joint Users Group (JUG)
Meeting #4 Minutes
May 6, 2015
Salt Lake City, UT
1.
Welcome
Philip Augustin, Incoming Technical Studies Subcommittee (TSS) Chair, called the meeting to
order at 8:15 am on May 6, 2015. A list of attendees is attached as Exhibit A.
Enoch Davies reviewed the WECC Antitrust Policy.
Attendees introduced themselves.
2.
Review Agenda
Mr. Augustin reviewed the agenda.
3.
Approval of Meeting #3 Minutes
Lesley Kayser-Sprouse reviewed the minutes from the last meeting.
APPROVAL ITEM: John Gross made a motion to approve the minutes that was seconded by David
Gustad. The motion passed unanimously.
4.
Composite Load Model
Eric Bakie presented his observations using the WECC Dynamic Composite Load Model
(CMPLDW) based on a couple of validation events – one single-line ground fault and one threephase fault. He noted that a significant amount of load tripping is being observed in the model for
three-phase faults due to low voltage, even including loads far away from the fault location. It
appears that the CMPLDW motor trip pickup level and time delay parameters are very sensitive
and may be too conservative. This information will also be shared with Modeling & Validation
Work Group (MVWG) and WECC-0100 project team.
Jun Wen also mentioned that some MVWG members are performing some sensitivity studies,
and Mitsubishi Electric Power Products, Inc. (MEPPI) is also performing some sensitivity studies
with Phase 2 under a DOE-funded project.
It was agreed that the model structure is good and the issues are related to the data/parameters.
ACTION ITEM: MVWG to continue performing model validation with CMPLDW, review typical
motor-trip settings in the model (i.e., pickup level and time delay), provide recommended
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TSS JUG Meeting Minutes May 6, 2015
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changes, and provide guidance on how much load should be tripping for different types of faults.
MVWG to review whether there is the need for more complexity of the CMPLDW model.
ACTION ITEM: System Review Work Group (SRWG) to continue working with data submitters to
review the data for the CMPLDW and provide more accurate data.
ACTION ITEM: Eric Bakie to work with Joe Smith. Mr. Smith is requesting information from Mr.
Bakie’s study so that Power System Simulator for Engineering (PSS®E) can also perform
benchmark simulations to compare results.
5.
TPL-007
SRWG created a subgroup that developed a spreadsheet of the data to be requested for
Geomagnetic Disturbance (GMD) analysis (not program-vendor specific).
Enoch Davies will lead an advisory team that will:

decide which case/scenario(s) to study for GMD impacts;

evaluate other issues (e.g., sharing of lat/long info) for collecting the Geomagnetically
Induced Currents (GIC) data (including data validation); and

perform the GMD studies.
This advisory team will consist of eight representatives (two each) from:

Planning Coordination Committee (PCC)

Technical Studies Subcommittee (TSS)

System Review Work Group (SRWG)

Reliability Subcommittee (RS)
The Request for Proposals (RFP) has not yet been awarded. The scope is currently to collect the
GIC data, perform data validation, and get the data set up in a software program to be ready for a
study. Performing the study would be the next step. WECC management will select a proposal
and inform the JUG, preferably by the next PCC meeting.
Mr. Davies will be setting up a GMD RFP advisory team WebEx meeting.
6.
Conversion Issues between PSS®E and Positive Sequence Load Flow (PSLF)
Gordon Comegys presented that he is seeing an issue with converting multi-section lines from
PSLF Electronic Product Code (EPC) to PSS®E raw file format in the conversion program because
the from bus and to bus are sometimes swapped. This is still being seen even though about a year
ago, WECC has started using a mapping file to make dummy bus numbers consistent for all cases.
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There was discussion about how and when multi-section lines should be modeled. It was
discussed that there should be no more dummy buses for modeling series compensation. The
group discussed the modeling concept to make sure it is making improvements to move toward
being able to easily compare against West-Wide System Model (WSM) node-breaker model.
ACTION ITEM: SRWG to discuss the use of dummy buses (no longer use multi-section lines) in the
Interconnection-wide base cases (explicitly model series compensation with buses on both sides).
ACTION ITEM: Gordon Comegys to work with Rikin Shah/Joe Smith to see if they can fix the
conversion file for multi-section lines.
Mr. Comegys said he is seeing an issue with converting the series capacitor from PSLF to PSS®E –
a bypassed Static Var Device (SVD) will be converted to a very small impedance line, and you
would lose the SVD model. The raw file format does not have a flag that it was a series capacitor.
Options that were discussed included: 1) add a bypass flag in PSS®E and 2) model the series
capacitor as a separate line. PSS®E SVD's had an ID, so PSLF and PowerWorld does not need to
create one.
Gordon requested for the PSS®E software to handle multiple SVD's at a single bus (instead of
creating separate individual buses that are dummy buses), similar to PSLF and PowerWorld.
ACTION ITEM: SRWG Chair (John Gross) and PSS®E Program User’s Work Group Chair (Rikin Shah)
to make a written request to PSS®E to not lose the series capacitor information when converting
the data from PSLF, and to be able to model multiple SVDs connected to a single bus.
The Intermountain (IPP) line is modeled as a multi-terminal DC line in PSLF and a two-terminal DC
line in PSS®E. This model needs to have the same model in all programs.
ACTION ITEM: Rikin Shah to follow up to make sure the same model for IPP is being used in PSS®E
and PSLF.
John Gross identified the need for the eight ratings to be able to properly convert into PSS®E’s
three ratings. Joe Smith informed the group that this will be taken care of in PSS®E V34 because it
is being expanded to have 12 ratings.
ACTION ITEM: Rikin Shah to discuss the conversion program so that it takes the appropriate PSLF
ratings (see the TSS Data Preparation Manual for the description of the eight ratings) and
converts them into PSS®E’s existing three ratings.
ACTION ITEM: Rikin Shah to follow up with PSS®E user group to determine how they want to
handle the eight ratings when they have 12 ratings available.
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TSS JUG Meeting Minutes May 6, 2015
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4
Post-Transient Methodology
Tracy Rolstad commented that there is an old WECC post-transient methodology from the late
1990’s (Section 6 of “Voltage Stability Criteria, Undervoltage Load Shedding Strategy, and
Reactive Power Reserve Monitoring Methodology,” May 1998) and recommends that the posttransient methodology be updated (e.g., the list of governors that are blocked is out of date). Mr.
Rolstad also commented that this will benefit study engineers because there has been an issue
that the assumptions used by operations engineers and planning engineers have been different
and therefore seeing different issues.
He also discussed ensuring the programs are capable of modeling the devices that can act in the
post-transient time frame (e.g., shunt devices, SVCs, governors). Jamie Weber presented the
relevant items that are in the RAS and contingency common format, particularly whether
generators can respond (Automatic Generation Control), how much of each responds based on
make-up power (e.g., participation factor), max megawatt response for each unit, and how it
responds (such as with line drop compensation). There is also a way to define a Voltage Control
Group that consists of multiple switched shunts that can respond to contingencies.
ACTION ITEM: Tracy Rolstad to update the WECC post-transient methodology and make it an
independent document. He is to get feedback from SRWG, MVWG, and TSS.
John Gross raised the desire to represent some of the transient modeling data in the steady state
environment for contingency analysis, such as LHVRT, MSC1. Overcurrent relay model
specifications (LOCTI, TIOCR1, TIOCRS) are already included this request.
ACTION ITEM: Philip Augustin to work with Program User Work Group Chairs to request the
program vendors to add the capability to take information from the dynamic models LOCTI,
TIOCR1, TIOCRS, LHVRT, and MSC1 and be able to model the appropriate actions in the steady
state environment for contingency analysis.
8.
RAS and Contingency Workshop
Scheduled for May 27-29, 2015, in person only.
9.
Action Items
Stephanie Lu reviewed the action items.
10. Adjourn
Mr. Augustin adjourned the meeting at 12:15 pm on May 6, 2015.
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Exhibit A: Attendance List
In Attendance
Name .................................................................................................................................. Affiliation
Philip Augustin .................................................................................... Portland General Electric Company
Enoch Davies .............................................................................. Western Electricity Coordinating Council
Long Duong ............................................................................. Public Utility District of Snohomish County
David Franklin ................................................................................... Southern California Edison Company
John Gross ..................................................................................................................... Avista Corporation
David Gustad .............................................................................................................. Tri-State Generation
Lesley Kayser-Sprouse ...................................................................... Hetch Hetchy Water & Power (CCSF)
Stephanie Lu ..................................................................................................................... Seattle City Light
Chris Mensah-Bonsu .................................................................. California Independent System Operator
Tracy Rolstad ................................................................................................................. Avista Corporation
Rikin Shah .................................................................................................................................... PacifiCorp
Joe Smith ................................................................................................................................... Siemens PTI
Jun Wen ............................................................................................. Southern California Edison Company
via Webinar
Name .................................................................................................................................. Affiliation
Bob Micek ............................................................................................................. Turlock Irrigation District
CJ Jing ............................................................................................... Southern California Edison Company
Eleanor Ewry ................................................................................................................ Puget Sound Energy
Eric Bakie ................................................................................................................... Idaho Power Company
Gordon Comegys......................................................................................................................WestConnect
James Hadley ............................................................................................................ NorthWestern Energy
Jamie Weber ........................................................................................................ PowerWorld Corporation
Jonathan Young....................................................................................................................... ColumbiaGrid
Joseph Gillette .................................................................................. Sacramento Municipal Utility District
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Nathan Powell ............................................................................ Western Electricity Coordinating Council
Shawn Carlson ......................................................................................... Basin Electric Power Cooperative
Shengli Huang .............................................................................................................. Puget Sound Energy
Western Electricity Coordinating Council