WECC LMTF Update
NERC LMTF meeting, Salt Lake City
January 2016
Why it Matters
• The load model has a major impact on oscillation damping
• The load model has a major impact on FIDVR
• A significant amount of load loss can occur due to end-user
tripping
• Loads are becoming less grid-friendly (more power electronics)
• Distributed generation is increasing
History of Load Modeling (in WECC)
• Analysis of August 1996 disturbance showed that a dynamic load
model was needed to better capture inter area oscillations
History of Load Modeling (in WECC)
• 2002 – WECC “Interim” Load Model
 20% induction motor (MOTORW), remaining static load
 Was intended to be temporary fix
 Model limitations were recognized and need for a better model was clear
• In August 2000, another disturbance occurred
• Analysis showed that even the 20% induction motor was not
adequate to represent oscillation damping
August 4th, 2000 disturbance
546
544
542
540
538
536
534
532
530
528
526
524
0
5
10
Voltage Actual
15
20
25
Simulations - Conentional
30
35
40
Simulations - Composite Load Model
45
50
WECC Load Modeling Task Force
• 2002 – WECC develops the Load Model Task Force
• 2005 – WECC developed ‘explicit’ model
 Added distribution equivalent
 Modeled induction motor and static loads
 Numerical stability in Interconnection-wide study
o This was a big step … 10 years ago … still unavailable in the East …
• 2007 – First version of the composite load model in PSLF
 Three phase motor models only, no single phase represented
• 2006-2009 – EPRI/BPA/SCE testing residential air conditioners and
developing models
• 2009 – single phase air conditioner model added to composite load
model
• 2013 – WECC approved use of CMPLDW phase 1 model for planning
and operational studies
The CMPLDW Model
Recent Work
• June 2015 meeting
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Building Survey: Motor Protection and Control (Kueck, James, PNNL)
Single Phase AC performance testing (Bernie, Dmitry)
3ph and 1ph motor analysis (John Undrill)
Model Validation
o Idaho Power event (Eric Bakie)
o Southern California Edision event (Jun Wen)
 Efficient data management
• November 2015 meeting
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MEPPI sensitivity study
Phase 2 roadmap discussion
Porting CLM to WSM cases (breaker node model)
Update to WECC voltage dip criteria
Future Vision
• 1-2 years
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Consistent, robust rules for initialization (phase 1 and phase 2)
Efficient data management
Improved Protection Modeling
Load Model Data tool development
Benchmarking between software programs (phase 1 and 2)
• 2-5 years
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Component Model Flexibility (Plug and Play Capability)
Improved Air Conditioner Models
Updates to Distributed Solar Generation and Energy Storage Models
Model Validation studies
• 5-10 years
 Collecting and Coordinating load model data
 Adopt CLM for steady state studies
• 10+ years
 Promote CLM as standard load model for bulk grid studies (IEEE wide)
Current Priorities
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•
•
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Priority 1: Robust initialization rules
Priority 2: Improved Protection Modeling
Priority 3: Efficient Data management
Priority 4: Benchmarking between programs
Full Work Plan
Coordination with NERC LMTF
• Need to expand user base
 Educational Webinars and Workshops
• Develop data sets for different regions
• Expand model validation studies
• Develop industry wide knowledge of impact of dynamic load
modeling
• Distribution/Load modeling will become more important for
bulk grid studies of the future