Item 8- Overhead Distribution Resilience Study — original pdf

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Overhead Distribution Resilience Study A step toward a comprehensive Distribution Resiliency Plan David Tomczyszyn Vice President, Electric System Engineering & Technical Services Austin Energy Michael Cote Project Delivery Director – Energy & Utility Consulting 1898 & Co. July 2025 © Austin Energy Item 8Agenda Austin Energy System Overview & Background Overhead Resilience Study Next Steps & Questions 2 The Why Recent Events Recent storms, including Uri, Mara, and the May Microburst — reinforce the importance of investments to strengthen the electric grid. Federal Funding Austin Energy proactively sought federal funding to assess and improve resiliency. Goal Strengthen Austin Energy’s electric distribution system to better withstand and recover from major events. 3 FEMA Building Resilient Infrastructure and Communities (BRIC) Pre-Project Funding Grant Assess the current-state overhead distribution system for opportunities to harden, automate, and sectionalize to enhance load shed, critical load isolation, and cold load pickup capabilities during blue sky and severe weather events. 4 Distribution Resiliency Plan Overhead Resiliency Study Underground Feasibility Study Distribution Resiliency Plan Existing Reliability Programs 5 STUDY INTRODUCTION 6 1898 & CO. PART OF BURNS & McDONNELL 1 8 9 8 & C o . | P E O P L E 600+ Specialists in Planning, Technology, and Consulting T E X A S R E S I L I E N C Y S T U D Y E X P E R I E N C E ( S P S O N L Y ) 7 STUDY SCOPE OVERHEAD DISTRIBUTION RESILIENCE STUDY Grant Funded Opportunity AS-IS STATE: Analyze the design and operation of the distribution system against Austin Energy’s current philosophies and standards to identify areas of improvement. FEEDER COORDINATION STUDIES: Individual coordination studies performed on each feeder incorporating Austin Energy’s current fusing and grid automation devices. FUTURE STATE: Initiatives detailing new technologies and industry trends Austin Energy should consider when developing future resilience strategies. TASK 1 TASK 2 TASK 3 Included interviews across Austin Energy work groups. Benchmarked against industry trends. 8 AS-IS STATE 9 AS-IS STATE| SCOPE Evaluate the current capabilities of Austin Energy’s overhead distribution system to inform future planning. STANDARDS CAPACITY ANALYSIS LOAD SHED DER HOSTING CAPACITY Evaluate design standards and check equipment compliance using Geographic Information Systems (GIS) and system models Identify feeders and substations nearing thermal or voltage limits Quantify current and potential load shed capability in response to ERCOT-directed events Assess system readiness to integrate more Distributed Energy Resources (DERs) without power quality issues 10 AS-IS STATE| RECOMMENDATIONS Prioritize Replacement of Legacy or High-Risk Infrastructure Conduct condition-based assessments and accelerate phased replacement of aging, underperforming, or non-standard equipment, particularly those on lower-performing feeders. 01 Improve Data Integration Across Systems Develop consistent asset identification numbers/names that enable data- sharing and correlation across Advanced Metering Infrastructure (AMI), Supervisory Control and Data Acquisition (SCADA), Geographic Information System(GIS), and planning models to streamline studies. 02 Monitor High-Need Substations for Capacity Planning Consider prioritizing the substations identified as nearing thermal or voltage thresholds for modeling refinement and closer monitoring for potential upgrades. Expand Load Shed Flexibility Through Automation Austin Energy can shed through full-circuit SCADA control. Enhancing automation with reclosers and smart switches could boost load shed capacity while minimizing customer impact. 03 05 Modernize Distributed Energy Resource (DER) Interconnection Standards Include smart inverter settings, voltage and frequency ride-through behavior, limited export functionality, and enhanced screening processes aligned with IEEE 1547-2018 and peer utility practices. 04 Refine Hosting Capacity Methodology Incorporate forecasted load profiles, raise transformer DER penetration thresholds, and tighten voltage deviation limits. Consider proactive hosting capacity infrastructure upgrades and refined DER siting support to alleviate future bottlenecks. 06 11 FEEDER STUDIES 12 FEEDER STUDIES| SCOPE Feeder-by-feeder studies to recommend devices and evaluate protection coordination to support grid resiliency. Determine recommended count and location of mainline reclosers per circuit for optimal sectionalization. Determine recommended count and location of lateral reclosers per circuit to further improve resiliency. Coordinate recommended protective device as defined in the Austin Energy protection manual. 13 DEVICE PLACEMENT| PURPOSE AND METHOD OBJECTIVE Install more sectionalizing devices (Recloser) to increase Austin Energy’s ability to isolate a fault or perform maintenance. OUTCOMES Fewer customers will be impacted by planned and unplanned outages by reducing customers per zone with potential alternative paths to supply power. Before Reclosers Circuit A Breaker A Circuit B Substation Breaker B After Reclosers Circuit A Substation Breaker A Switch open S1 Circuit B Breaker B Fault due to tree limbs, equipment failure, storm S2 Switch open Faulted section isolated S2 Switch open R Recloser 2A - Open R Recloser 2B - Closed R Recloser 1A - Open R Recloser 1B - Closed S3 Switch closed 14 DEVICE PLACEMENT| PURPOSE AND METHOD Sub • Feeder ‘X’ has 2,200 customers with a peak load of 9 MW • This feeder will be segmented into functional “pods” • Ideally, pods should contain an equal load, the same overhead exposure, a similar number of customers • Due to the factors, including critical load locations, achieving ideal device placement is not always possible Pod Description Feeder Length (Mi) Customers MW 1 2 3 Next to station breaker Downstream of Recloser R1 Downstream of Recloser R2 Total 3.6 2.1 0.7 6.4 400 1,000 800 2,200 2.1 3.1 3.8 9.0 R1 Clear Momentary R2 Faults Tie Feeder - 1 Tie Feeder - 2 15 DEVICE PLACEMENT | RECOMMENDATIONS Expand Mainline Reclosers Segment feeders with additional reclosers to isolate faults, reduce outage impacts, and lay the groundwork for future automation like Fault Location, Isolation, and Service Restoration (FLISR). Deploy More Lateral Reclosers Prioritize lateral reclosers in high-risk or remote areas to reduce sustained outages from momentary faults and enhance service reliability. Standardize Breaker Relay Settings Align relay settings where feasible to streamline coordination, simplify future recloser deployments, and support system consistency. 01 03 05 Leverage and Strengthen Feeder Ties Increase capacity of existing ties and consider creating new ties to enable faster restoration and improve flexibility for load transfers during outages. Modernize Lateral Protection Strategy Combine lateral reclosers with updated fuse coordination practices to improve protection timing and reduce unnecessary fuse operations. 02 04 16 FUTURE STATE 17 FUTURE STATE | PURPOSE AND METHOD Developed 24 actionable initiatives, grouped into five major themes to guide long-term resiliency investments. Infrastructure Resilience Strengthen grid assets to better withstand extreme weather and future demands. Data-Driven Operations Use analytics to guide proactive, risk-informed operational decisions. Grid Connectivity Expand and automate monitoring and control to improve real-time visibility and flexibility. Emergency Readiness Operational Excellence Enhance preparation, training, and coordination to speed response and restoration during extreme events. Optimize internal processes, governance, and resource management to accelerate resiliency outcomes. 18 FUTURE STATE | RECOMMENDATIONS 1898 & Co. recommends that Austin Energy take a low-risk parallel pathway approach that will provide some near-term impacts and establish a sustainable long-term program to transition infrastructure and operational practices toward a robust and resilient future. Near-term Initiatives Tackle priority initiatives in separate areas with distributed ownership for immediate impacts in various areas. Realize modest improvements in areas and capture lessons learned to inform a comprehensive program. Long-term Preparation Develop Distribution Resiliency Plan and structure a comprehensive program and budget. Launch Long-term Program Launch a comprehensive and sustainable long-term program. 19 NEXT STEPS 20 Distribution Resiliency Plan Overhead Resiliency Study Underground Feasibility Study Distribution Resiliency Plan Existing Reliability Programs 21 Next Steps Timeline Analyze Undergrounding Study Results Receive Overhead Study Results Ongoing May 2025 Develop Comprehensive Distribution Resiliency Plan Use studies, further analysis and stakeholder engagement to inform near- and long-term priorities Present Distribution Resiliency Plan Late 2025 22 QUESTIONS? ©Austin Energy. All rights reserved. Austin Energy and the Austin Energy logo and combinations thereof are trademarks of Austin Energy, the electric department of the City of Austin, Texas. Other names are for informational purposes only and may be trademarks of their respective owners.