NERC LMTF: Current Activities Ryan Quint, PhD, PE Staff Coordinator, NERC Load Modeling Task Force WECC MVWG Meeting June 2016

RELIABILITY | ACCOUNTABILITY2 Update Chair: Dmitry Kosterev, BPA Meetings  Kickoff Meeting – Salt Lake City, January 2016  Second Meeting – Washington DC, May 2016  Next Meeting – TBD, Sept/Oct 2016 Coordination with Regional load modeling groups Broad group of expertise involved  Utility planners  Software vendors  Modeling and load behavior experts Looking for full industry coverage/participation  “Consolidate” load modeling practices across industry

RELIABILITY | ACCOUNTABILITY3 LMTF Tasks Task #Task 1Technical Reference Document Out for comment/review now, approval call scheduled for Friday, June 17 July: SAMS approval; September: PC acceptance (publication) Current state of dynamic load modeling Follow-up to FIDVR Workshop in Alexandria, VA in 9/2015

RELIABILITY | ACCOUNTABILITY4 LMTF Tasks Task #Task 2 Common Initialization Procedures Standardized procedures for software initialization – overcome “crashing” issues 3Network Boundary Equations Common practices for dealing with current source in dynamics – motor model numerical issues resulting in “crashing” Source: PowerWorld

RELIABILITY | ACCOUNTABILITY5 LMTF Tasks Task #Task 4Load Model (Software) Benchmarking Ongoing benchmarking of PSS®E, PSLF, PowerWorld, etc., composite load models Uncovering and fixing software issues – standardize platforms Source: PacifiCorp Source: PowerWorld

RELIABILITY | ACCOUNTABILITY6 LMTF Tasks Task #Task 5Improved Protection System Modeling Discrete protection system operations is not sufficient – addressing this issue Source: PowerWorld Source: J. Undrill

RELIABILITY | ACCOUNTABILITY7 LMTF Tasks Task #Task 6 Improved Single-Phase Motor Model Performance model replacement 7Improved Three-Phase Motor Model Improved motor modeling for 3-phase motors – not a major issue Three-phase motor dynamic models using flux equations  Consistent with motor1 model in PSLF Upgrade ld1pac model numerical performance Explore stalling characteristic changes Protection and controls models integration

RELIABILITY | ACCOUNTABILITY8 LMTF Tasks Task #Task 8Robust (Default) Data Sets Develop robust data sets for use across regions Develop regionally (load type) reasonable starting points Consistency in datasets Understanding sensitivities Regional, local starting points for default values Consistent protection and control parameters

RELIABILITY | ACCOUNTABILITY9 LMTF Tasks Task #Task 9Reliability Guideline: Load Composition Developing a Reliability Guideline on developing load composition data Source: WECC Source: CEUS Source: BPA

RELIABILITY | ACCOUNTABILITY10 LMTF Tasks Task #Task 10Educational Materials & Industry Webinar Ongoing industry education – webinar/workshop in the works Planning industry webinar on dynamic load modeling Broader industry engagement  Fundamentals  Composite load model  Parameters and their meaning  Load composition  Distributed generation modeling  System analysis and modeling Data TBD (Q3/4 2016) – coordinating with Regional groups

RELIABILITY | ACCOUNTABILITY11 LMTF Tasks Task #Task 11System Impact Studies Hearing from entities on findings/experiences

RELIABILITY | ACCOUNTABILITY12 LMTF Tasks Task #Task 12Efficient Data Format & Model Management Exploring new composite load model structure and model management concepts

RELIABILITY | ACCOUNTABILITY13 LMTF Tasks Task #Task 13Distributed Generation Modeling Guidance Best practices on how to handle DG in simulations Exploring best approach for including DG in dynamic load models  Developing “industry best practices” – technical guidance for industry Usability and accuracy testing and validation

RELIABILITY | ACCOUNTABILITY14 LMTF Tasks Task #Task 14Dynamic Load Modeling in Real-Time Stability Analysis Surveying what dynamic load models are being used in real-time studies Survey of LMTF member practices Benefits/needs Relation to planning realm Impacts on online transient stability analysis Inclusion of induction motor load of some sort Obstacles, challenges, path forward

RELIABILITY | ACCOUNTABILITY15 Coordination Items with WECC LMTF & MVWG Distributed Generation Modeling Guidance Software Benchmarking Robust Default Datasets Modularized Approach

RELIABILITY | ACCOUNTABILITY16 Modeling Guidance: Distributed Generation For purposes of this discussion, we use the following definitions: Distributed Generation (DG): Utility-scale generating resources integrated at the distribution level such as industrial or commercial rooftop solar photovoltaic (PV) installations, or solar PV power plants. Distributed Energy Resources (DER): Smaller-scale individual installations of generating resources at the distribution level such as residential rooftop solar or other behind-the-meter generation.

RELIABILITY | ACCOUNTABILITY17 Modeling Guidance: Distributed Generation Simple Powerflow Modeling Modeled Distribution Transformer

RELIABILITY | ACCOUNTABILITY18 Modeling Guidance: Distributed Generation Composite Load Model in Stability Programs

RELIABILITY | ACCOUNTABILITY19 Modeling Guidance: Distributed Generation DER in the Composite Load Model

RELIABILITY | ACCOUNTABILITY20 Modeling Guidance: Distributed Generation DER and DG in the Composite Load Model

RELIABILITY | ACCOUNTABILITY21 Modeling Guidance: Distributed Generation Recommended Modeling Practice for DG and DER in Dynamic Load Models

RELIABILITY | ACCOUNTABILITY22 Modeling Guidance: Distributed Generation Thresholds for DG and DER Modeling DG Modeling: Any individual DG facility rated 10 MVA or higher should be modeled explicitly in the powerflow case at the low- side of the transmission-distribution transformer. A dynamics record, such as PV1 model, is required to account for the transient behavior of this plant. DER Modeling: If the gross aggregate nameplate rating of all distributed resources including DG and DER exceeds this threshold, these distributed resource should be accounted for in dynamic simulations as part of the dynamic load model. While this may not require any explicit representation in the base case, the amount of DER should be accounted for in the load record and/or integrated into the dynamic model.

RELIABILITY | ACCOUNTABILITY23 Modeling Guidance: Distributed Generation Thresholds for DG and DER Modeling (Cont.) EXAMPLE What should these thresholds be? Looking for WECC MVWG/LMTF/REMTF input here.

RELIABILITY | ACCOUNTABILITY24 Modeling Guidance: Distributed Generation Recommended Modeling Practices Defined thresholds for DG for explicit modeling in powerflow and dynamics cases Defined thresholds for DER for explicit representation in the dynamic load model (and powerflow, as applicable) Inclusion of DER as part of powerflow modeling requirements Use of PV1 model, or comparable, for representing the DG Use of composite load model, or comparable, for representing the DER in the dynamics case Use of (modified) LTC1 model to represent LTC actions in dynamics (area- or zone-based with voltage thresholds) Looking for feedback on draft recommended practices

RELIABILITY | ACCOUNTABILITY25 Software Benchmarking Need to coordinate on benchmarking efforts WECC LMTF developing report on benchmarking  How is this getting integrated into a standardized process?  Have each of the Coordinated plan at last NERC LMTF meeting  Utility industry (NERC/WECC LMTF members) develop test suite of event datasets  Provide test datasets to vendors  Vendors to perform benchmarking for each test dataset using playback models  Vendors to provide results in standardized data format for NERC/WECC LMTF review and reporting Future models must be numerically stable for all test datasets

RELIABILITY | ACCOUNTABILITY26 Software Benchmarking Load Model Test Dataset Underfrequency Event Overfrequency Event Voltage Ramp Normally Cleared 3-phase Fault Delayed Clearing 3-phase Fault Sustained Voltage Sag – 90% Sustained Voltage Sag – 75% Voltage Swell (Overvoltage) Oscillation Frequencies

RELIABILITY | ACCOUNTABILITY27 Robust Default Datasets Hamody brought up discrepancies between current WECC.dyd compared with NERC LMTF recommended default parameters Motor protection parameters changed based on recent meeting discussion and understanding of end-use loads  Ttr1A changed from 0.02 ms to 0.1 ms –EMS-type tripping, not contactors  May have significant impact for normally cleared main grid faults Slightly different Vtr1A/1B/1C voltage trip thresholds  Reduced by 0.05 pu, may have impact on simulation results Questions:  Process for making these type of changes to the WECC CLM records?  Is WECC LMTF/MVWG going to adopt these new default parameters? Want to bring this up for discussion with WECC LMTF membership

RELIABILITY | ACCOUNTABILITY28 Modularized Modeling Approach Modular, simplified load model dataset is a need across industry PSLF currently testing new approach  What are other software vendors doing? What is their plan? This needs to be coordinated. Discussions at NERC LMTF to explore simplified CLM/new CLM  Represents distribution system  Uses more up-to-date motor models  Includes progressive tripping/stalling functions for motors  Significantly simplified dataset  Would like to get WECC LMTF membership feedback

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