Review of Data Change Management Processes for RTCA and Planning Models (Recommendation 16) March, 2017

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1 Review of Data Change Management Processes for RTCA and Planning Models (Recommendation 16) March, 2017 Background In April 2012, the Federal Energy Regulatory Commission (FERC) and the North American Electric Reliability Corporation (NERC) issued the joint report, Arizona-Southern California Outages on September 8, 2011 (Outage Report). Discrepancies identified between real-time contingency analysis (RTCA) and planning models were the subject of Recommendation 16 of the Outage Report: [Western Electricity Coordinating Council] WECC should ensure consistencies in model parameters between its planning model and its RTCA model and should review all model parameters on a consistent basis to make sure discrepancies do not occur. The Modeling Working Group (MWG) recommended implementation of data change management processes that include requirements for Generator Owners (GO) and Transmission Owners (TO) to notify Transmission Planners (TP), Transmission Operators (TOP), Reliability Coordinators (RC), Planning Coordinators (PC), et al, whenever there are changes made to the system that must be reflected in planning, operational, and real-time models. The NERC Planning Committee approved the following implementation plan for reviewing data change management processes: 1. Review existing requirements in the NERC Reliability Standards. (February 2014) 2. Review existing requirements in the Regional procedures. (February 2014) 3. Identify industry best practices and communicate them to the regions (March 2014) 4. Identify gaps in data change management processes, if any. (April 2014) 5. Ascertain status of North American Transmission Forum (NATF) and North American Generation Forum (NAGF) efforts on data change management. (July 2014) 6. Write a summary of the findings from steps 1 through 4. (August 2014) 7. Develop a list of recommended practices for approval by Planning Committee or Operating Committee. (Sept 2014) 8. Work with Regional Entities to facilitate the implementation of these recommended practices. (Dec 2015) The summary of the findings (step 6) and the list of recommended practices (step 7) are presented in this document.

2 NERC Standards Current NERC standards do not provide specificity on data change management processes for modeling elements in real-time or off-line models; rather, these specifics are left to procedures that the standards mandate be created. The most direct requirement for a data change management process is found in FAC R1 requires that Each Transmission Owner shall document Facility interconnection requirements, update them as needed, including generation, transmission and end-user facilities. R3 requires that TO s incorporate procedures for coordinated studies of new or materially modified existing interconnections and their impacts on affected system(s). IRO-010-1a 2, R3 requires each TO and GO to provide the modeling information to RCs for the models that support Real-time monitoring, Operational Planning Analyses, and Real-time Assessments of its Reliability Coordinator Area to prevent instability, uncontrolled separation, and cascading outages. (R1 requires the RC to develop a procedure for the provision of such data.) Similarly, MOD requires Each Balancing Authority, Generator Owner, Load Serving Entity, Resource Planner, Transmission Owner, and Transmission Service Provider to provide steady-state, dynamics, and short circuit modeling data to its Transmission Planner(s) and Planning Coordinator(s) according to the data requirements and reporting procedures developed by its Planning Coordinator and Transmission Planner. The Planning Coordinator is then required to provide the modeling data for its footprint to the appropriate party responsible for building the Interconnection wide cases. NPCC The Northeast Power Coordinating Council, Inc. (NPCC) does not perform any Reliability Coordinator (RC) or Planning Coordinator (PC) related functions. Pursuant with NERC Reliability Standard MOD-032-1, data from applicable data owners are submitted to the associated TP and Planning Coordinators. NPCC s SS-37 Working Group on Base Case Development was established in the 1990s and is still in existence today. SS- 37 is comprised of the NPCC area PCs. Through the SS-37 working group, NPCC coordinates the development of designated power flow base cases, including the dynamics data by the PCs. The SS-37 deliverables are created using the guidelines and procedures codified in the Eastern Interconnection Reliability Assessment Group (ERAG) Multiregional Modeling Working Group (MMWG) Procedural Manual. The ERAG-MMWG is comprised of representatives from the Planning Coordinators (PC) in the Eastern Interconnection as well as liaison representatives of the North American Electric Reliability Corporation (NERC), the Federal Energy Regulatory Commission (FERC), and the Regional Entities in the Eastern Interconnection. At least one member of the NPCC SS-37 working group serves as the NPCC PC representative on the ERAG-MMWG, thereby ensuring seamless communications between SS-37 and the ERAG-MMWG. 1 FAC Facility Interconnection Requirements 2 IRO-010-1a Reliability Coordinator Data Specification and Collection 3 MOD Data for Power System Modeling and Analysis Discrepancies Between RTCA and Planning Models (Recommendation 16) 2

3 MRO The Midwest Reliability Organization (MRO) does not perform any Reliability Coordinator (RC) or Planning Coordinator (PC) related functions. The appropriate RCs and PCs within the MRO Region are responsible for the daily operations and planning of the bulk power system. These entities either develop their own in-house operations and planning models or utilize the ERAG-MMWG Powerflow models as the off-theshelf starting base case models which is then updated by each of the RCs and PCs to meet their needs. MRO also does not perform any Real Time Contingency Analysis (RTCA) or any other related real-time studies. The applicable registered entities are expected to provide accurate modeling data based upon their current operations and planning topologies to MMWG consistent with the Eastern Interconnection Designee modeling requirements and the current MOD and MOD standard requirements. SERC SERC Reliability Corporation does not perform any of the NERC registered entity related functions. RCs, PCs, and TOPs within the SERC footprint and their associated TPs are responsible for the daily operations and planning of the bulk power system within their boundary areas. The applicable registered entities within SERC coordinate within the SERC committee structure and provide accurate data for regional model building and assessments. Within the SERC committee structure, four study/working groups listed below compile planning models, perform regional assessments and analysis. While the PCs are responsible to provide the data associated with MOD , the SERC Long-Term Study Group (LTSG), Dynamics Study Group (DSG), and Short Circuit Data Working Group (SCDWG) are the vehicles to provide coordinated information to support the requirements associated with MOD SERC Study/Working Groups SERC Near-Term Study Group (SERC-NTSG) Steady State Models SERC Long-Term Study Group (SERC-LTSG) Steady State Models SERC Dynamics Study Group (SERC-DSG) Dynamic Models SERC Short Circuit Data Working Group (SERC-SCDWG) Short Circuit Models Coordinated data include but are not limited to the following: Bus (substation) information Generating Units AC/DC Transmission Line or Circuit Transformer Reactive Compensation Interchange Schedules Discrepancies Between RTCA and Planning Models (Recommendation 16) 3

4 Inter-Regional Tie Line list Dynamics Data Short Circuit Data Special Protection Schemes (SPS)/Remedial Action Schemes (RAS) Operation Guides Equipment Ratings Contingency/monitored elements RF The ReliabilityFirst (RF) staff in conjunction with its stakeholder group, the Transmission Performance Subcommittee (TPS) performs several regional transmission assessments on an annual basis. The TPS is comprised of registered TO and the two independent system operator (ISO) s (PJM and MISO) within the RF footprint. For each study, a base case is selected from the latest series of Eastern Interconnection Reliability Assessment Group (ERAG) Multiregional Modeling Working Group (MMWG) cases and the TPS members are given an opportunity to update their footprint. While neither RF nor the TPS maintains a model building procedure document, the study procedure documents include several checks for model and contingency list inconsistencies. Also, many of the members of TPS use databases, excel workbooks or Model on Demand to assure accurate models. For the past two years, ReliabilityFirst staff has been performing comparisons of the summer seasonal power flow model with selected values from the time of the MISO and PJM summer peaks. These comparisons include a comparison of voltages at selected substations at 345 kv and above, and a review of the ratings and loadings of facilities that were heavily loaded on a first contingency basis in operations. SPP The Southwest Power Pool (SPP) is responsible for the daily operations and planning of the bulk power system for the SPP System and performs both Reliability Coordinator (RC) or Planning Coordinator (PC) related functions. As the Reliability Coordinator, SPP is responsible to monitor reliability and for emergency response pursuant to related SPP Tariff, SPP Criteria, NERC and SPP Regional Reliability Standards, and the all other applicable requirements. SPP is responsible for and performs its Planning Coordinator (PC) function, including transmission planning, in accordance with North American Electric Reliability Corporation (NERC) reliability standards. To perform its RC and PC function, SPP works with the appropriate registered entities and other applicable entities within the SPP System to develop appropriate operations and planning models that are utilized to meet the needs of SPP and other applicable entities. In regards to the RC function, SPP Operations utilizes the Alstom Model Change Submission Tool (MCST) to assemble real-time/power flow and Market data from the applicable Modeling Contacts. The MCST projects and profiles that are submitted by the Modeling Contacts follow an approval process internal to Discrepancies Between RTCA and Planning Models (Recommendation 16) 4

5 the Modeling Contacts, with final acceptance and approval by SPP staff. These different steps access the validity of the data: Once the data has been submitted, approved, and accepted through MCST, the projects are timed for inclusion in the proper model build/update. SPP updates the operations network model once a month. SPP and its modeling contacts make sure that the data in the MCST is up to date and coordinated with SPP s first tier companies throughout the year. One example of this is a monthly call with MISO and TVA where changes to each system are discussed. SPP s tools allows for the validation of the following data in the network model, among other things: Branch impedance Branch ratings Generator maximum limits Load and generation registration Transmission line flows sum to a reasonable mismatch at all SPP market area buses Results of contingency analysis are compared with BAs, thus validating our models against member s contingency analyses Generator outputs do not exceed modeled maximum and minimum capacities Compare the impacts of coordinated flow-gates with those entities Exchange EMS models with neighboring RCs and utilities The equipment changed (add/remove/edit) with each monthly model update is reviewed with a record by record validation that changes the following items where intentional: Stations Buses Breaker and breaker connectivity Generation unit Lines, transformers, bus load, and reactive devices System one-lines of each substation are generated and reviewed so that topology changes can be visualized. TOP and GOP submitted outages for transmission elements and generators are mapped against the EMS model any divergence indicates missing transmission elements or generators. For the PC Function, SPP utilizes the SPP Models on Demand (MOD) Web Portal to obtain data submitted by applicable registered and non-registered entities, which are data owners responsible for providing the data necessary to model their assets to its Transmission Planner(s) (TPs) and Planning Coordinator(s). SPP uses the MOD data submitted by the responsible entities to build and update the applicable annual SPP Discrepancies Between RTCA and Planning Models (Recommendation 16) 5

6 Planning Model Series (i.e. the SPP steady-state, dynamics, and short circuit models). The MOD is updated periodically with the most current planning topology by the applicable registered entities (TP), (TO), (GO) and Resource Planners (RP), etc.) and applicable non-registered entities within the SPP System. These models are then updated with planning topology by each of these registered entities to create the annual SPP Model Series. Some features of the MOD tool and process includes: Web based Portal database entry system. Review and acceptance process by SPP Staff for all input data (projects, profiles, ratings, etc.). Continuous review of the models by the owners at each Pass of the case creation process and when model changes are applied to the database. For each set of SPP models created from MOD, a related Excel based Data Submittal Workbook is also generated. The Data Submittal Workbook includes: Transactions, Generator Data, Owner Mapping, Load Mapping, Expanded Bus Names & Translation, Non-Scalable Load, Area Summary Report, and Regional Ties. The Data Submittal Workbook is posted on the SPP File Sharing site. SPP reviews and validates the model data provided from the responsible entities and any issues where the cases and/or data do not match the expected workbook values are flagged and provided to the owners for correction. SPP performs and completes model building activities based on requirements of applicable SPP procedures, which are jointly developed, reviewed, and approved by applicable SPP Working Groups. SPP has several working groups that focus on model building for the SPP System, two primary groups are the Transmission Working Group (TWG) and Model Development Working (MDWG). The MDWG is responsible for building and maintaining the steady-state models and the SWG is responsible for maintaining the dynamic models. FRCC The FRCC has two working groups that focus on model building for the region, the Transmission Working Group (TWG) and the Stability Working Group (SWG). The TWG is responsible for building and maintaining the steady-state models and the SWG is responsible for maintaining the dynamic models. The FRCC utilizes Siemens Model on Demand (MOD) software to compile the regional load flow databank with inputs from all TOs in the FRCC region. The FRCC region adheres to the model building process outlined in the "FRCC Load Flow & Short Circuit Databank Procedural Manual" and in FRCC Dynamics Data for Power System Modeling and Analysis. The FRCC databank models are updated periodically throughout the year as changes are required. Discrepancies Between RTCA and Planning Models (Recommendation 16) 6

7 Texas RE The Network Model Management System (NMMS) is the centralized repository used by ERCOT for storing all network model information for the Texas Interconnection. This single application is used for submitting and changing the network model that is used to populate the application data bases for real time operations, the operating horizon, and the planning horizon. Some benefits of the Network Model Management System are: Single point of entry for Transmission entities. Members can only change data that they own or operate and can submit time-based model changes. The application database (EMS, MMS, OS, etc.) are updated 47 to 52 times per year, roughly once per week with a new database that reflects a specific point in time. Common Information Model (CIM) based, with ERCOT extensions. An industry standard format to exchange model data enables applications from different vendors to use the same model format. Topology Processor. Converts the CIM node-breaker model to a PSSE formatted bus-branch model for the planning horizon for specific points in time. Model On Demand (MOD). MOD is used in conjunction with the Topology Processor to synchronize the planning model with the CIM model used to populate the other network modeling processes such as EMS Operations. Planned projects are then added to MOD to produce models for specific dates in the future. Contingency definition builder. An ERCOT application that uses the topology of the network model to create the contingency definitions for each time-based model. Contingency names stay the same but the definition could change based on topology changes. The contingency definition always matches the network model. The ERCOT Network Modeling team and stakeholders, in accordance with ERCOT Protocols, ERCOT Planning Guide, and ERCOT Operating Guides, are involved in reviewing the input and output of the data management system to assess its data quality. Some challenges have been experienced with this data change management process: Multiple CIM schema extensions were needed as technology and business process for model management matured. Multiple vendors, multiple CIM driven software, and multiple road maps had to be coordinated. Cross-system synchronized upgrades and enhancements have posed logistical challenges. End-use driven modeling expectations can at times result in conflicting modeling practices for same type of equipment. Isolated alternate modeling methodologies were incorporated to supplement targeted end-user models. Data change execution strategies were defined so as to provide end users opportunities for a slow & guided transition. Dynamics data. CIM for dynamics models is in development. Currently a manual process is used to manage dynamics data changes. Discrepancies Between RTCA and Planning Models (Recommendation 16) 7

8 WECC In the Western Interconnection there are two separate, independent processes for updating interconnection wide cases 1) for the West-wide System Model (WSM) state estimator and 2) for base cases. WSM When there are changes that affect the models, the equipment owners are required to notify Peak Reliability and provide one-line diagrams and other documentation regarding the changes. The modelers at Peak Reliability then make the changes to the WSM based upon the information received. Base Cases When there are changes that affect the models, the equipment owners are expected to incorporate the changes into future data submittals. For planning cases, each Transmission Planner submits each case individually for their part of the system based upon a data request. WECC System Review Work Group (SRWG) and WECC Staff merge the submitted case into one system-wide case and send it out for review. The equipment owners then have another chance to verify their submittals. These procedures are documented in the "WECC Data Preparation Manual for Steady-State and Dynamic Base Case Data." Verification Using Events At least a couple of times a year WECC and/or Peak Reliability creates a case using WSM and Base Case as a starting point and simulates a system event. Event simulation results for WSM and base case derivative cases are compared with measurements to verify matching results. Industry Best Practices MWG identified the following best practices among data change management procedures: Benchmarking cases against events Quarterly update of databank models A single database (e.g. ERCOT NMMS) which provides a common source for real-time operations, operating horizon, and planning horizon models Gaps in Data Change Management Processes MWG did not identify any gaps in the NERC standards or Regional procedures for data change management. MWG did note that use of a single point of entry for interconnection model data significantly reduces the probability of errors and mismatches between operating and planning models, provided that data entries are checked for accuracy against their intended values. MWG notes that good software algorithms help identify erroneous data entries. Many such algorithms are based on the principle that each type of data generally lies within a known range. Discrepancies Between RTCA and Planning Models (Recommendation 16) 8

9 Recommended Practices MWG presents the following recommended practices for data change management to the NERC Planning Committee and Operating Committee for their approval: A database (e.g. ERCOT NMMS) that serves as a common source for real-time operations, operating horizon, and planning horizon models should be developed and used by the appropriate entities involved in model construction. Whenever system changes occur, the updated data should be entered into the database as soon as possible and notice be sent to the end user (an update script - idv file or similar- can be prepared or equivalent commands be inserted on user s scripts to implement the change in existing data sets.) Tracking of all data changes and the person(s) making them is essential. Benchmark cases against dynamic events or steady state operating conditions. Discrepancies Between RTCA and Planning Models (Recommendation 16) 9