Fall 2022 General Meeting

Hosted by: NC State


November 9 – 10, 2022


The Center for Advanced Power Engineering and Research (CAPER) is a collaboration among three universities and industry members focusing on research and educational needs in the electric power industry in the southeast region of the US. CAPER holds two General Meetings each year, spring and fall, each hosted by a member University. In attendance are CAPER researchers and students along with industry and government representatives to present current industry topics, update sponsored projects and take part in discussions about the Center’s research and education activities.


We wish to thank Dr. Mesut Baran, CAPER Center Co-Director at NC State University, for hosting this virtual meeting. Special thanks go to Shannon Jenkins for all the many arrangements that were required for this meeting. We also wish to thank our Industry Members, Faculty and Students for participating in the tutorial and General Meeting.


Location – The meeting took place at James B. Hunt, Jr. Library (Duke Hall, A-D)



Faculty – 17, Industry – 32, Students – 41


Wednesday November 9, 2022; 8 am – 12 noon – Tutorial: IBR Modeling 101 – 71 attendees


1:00 pm – General Meeting: Innovative Approaches of Integrating IBRs into the Grid


Steve Whisenant, Chair of CAPER Steering Committee opened the meeting with a warming welcome to those in attendance. Steve presented a background on CAPER, objectives for the day and sharing of In the News.


Plenary Session – Challenges of Operating a Power Grid with a High Penetration of IBR led by Mesut Baran, Center Co-Director NC State


Dr. Baran, opened the session stating that distributed energy resources (DER) had their beginning in rooftop solar. Now that are single installations in the hundreds of MWs interconnected to transmission systems.


These inverter-based resources (IBRs) present numerous impacts to the electrical circuits: voltage rise, power quality issues, excessive regulator operations, excessive transformer LTC operations, protection issues, capacity deferral, planning and operations. IBRs also present engineering challenges with the  intermittent power and generation control, low inertia and frequency regulation, location of generation and overloads on transmission systems and limited fault current creates protection challenges and stability.


Dr. Ian Hiskens, University of Michigan, a native of Australia; shared that Australia is on a path for 100% renewables in electric energy production with solar and wind leading the way. However, solar is more abundant in the middle of the country where there are no people and wind availability is mostly offshore. Where there are large populations, there is no wind. Current cost of electrical energy in Australia is $ 0.35 per KWh. Australia has experimented with storage but has concluded that lithium-ion batteries are not the solution. Australia is looking into ways to create more pumped hydro storage utilizing old, abandoned mines.


In May 2022m there was a market meltdown when 2GW of coal was lost and there was low wind and solar. Gas prices went high. On the spot market power was selling at $2000/MWh. Normal range is $60 – $100/MWh. Government introduced price cap at $300/MWh. Companies withdrew their capacity and electricity markets were withdrawn for the first time ever. Southern Australia has decommissioned their synchronous generation and added four synchronous condensers at a cost of $185M each.


Session I – Generation Control and EMS Considerations with High Penetration of IBR led by Mesut Baran Center Co-Director NC State


Weifeng Li, ERCOT, stated that the growth in renewables has led to reliability concerns caused by ramp rates created by solar and wind. The ramp can be as high as 1220MW/5min. ERCOT’s single generation contingency is 1375 MWs. Weifeng went on the explain the Security Constrained Economic Dispatch (SCED) and new Ancillary Services being set up within ERCOT.


Next Di Wu, PNNL, discussed energy storage analytics and demonstration projects that are underway. Storage can help solve problems in all parts of the grid. However, there is a lack of ability to model, optimize, value and control large energy storage systems (ESS).


Ignacio Vieto, GE Gas Power, shared challenges, and successes in Grid-Forming (GFM) wind turbines. GFM wind turbines can provide core support in inertia response and frequency droop. More advanced support would be in black start and islanding situations.


Victor Paduani, NYPA, explained the EMT models their AGile Lab is developing for Type 4 Wind Turbines.


Session II – CAPER Sponsored Sr. Design Projects led by Steven Whisenant, Chair CAPER Steering Committee


A Team from each of our three CAPER Universities presented their progress on this year’s CAPER sponsored senior design projects.


Reception – Hunt Library – Halls A-B

Job Fair – Commons Area 2nd Floor


Day Two:


The meeting started at 8:00 am with highlights of day one and objectives for the day by CAPER Steering Committee Chair, Steve Whisenant.


Session III – Emerging Modeling, Control, and Grid-edge Platforms for Operating High IBR Penetration Grids led by Badrul Chowdhury Center Co-Director UNCC


Hisham Othman, Quanta Technology, opened the session with a discussion of innovative transmission upgrades for IBR Integration. He stated that today in the US we have 1100 GWs of wind and solar installed capacity with another 1000 GWs in the queue. There will be a doubling in the next few years. Grid challenges are accelerating. There is a paradigm shift underway – Inverters are to be viewed as assets and improved grid utilization will allow more. We need to unlock the hidden capability by lowering curtailments and lowering interconnection costs.


Iqbal Husain, NC State, shared the work FREEDM Center is doing on Converter Modeling and Testing for IBRs. He introduced the Software in the Loop (SIL) development underway. He discussed “rules of the road” for integration of IBRs into the grid. He explored the question of how GFL and GFM IBRs should behave under AC fault conditions.


Johan Enslin introduced the team working on the CAPER base funded project, PG-02: Incorporating EV and EV Charging Stations into Integrated Resource Planning. The team provided an update on the progress since last meeting and remaining work to be performed.


The next project discussed is an enhancement project supported by all three Universities, EHP-09-PG: Developing large DER Protection Guidelines and Settings for Mitigating Systemwide Impacts across Transmission and Distribution Systems. This project is designed to create an integrated T&D model of a real T&D system with the objective of developing recloser protection settings at distribution DER sites. The protection settings are to be determined such that the recloser trips when required but does not trip the DER unnecessarily for transmission system faults. The team is using PSSE SINCAL as the software modeling tool in creating an integrated T&D model.


The session concluded with a project update on Phase III of the Power Flow Analysis to Improve Integrated Volt/Var Control (IVVC) and Energy Efficiency Programs. The Team provided a progress update and remaining work.


Session IV Grid Edge Platforms for High IBR Penetrations led by Ning Lu, NC State


Xiaonan Lu, Purdue University, discussed what the APECS is doing to study large scale integration of GFM inverters for resilient and sustainable energy systems and dynamic microgrids.


Amanuel Melese, ABB, explained how applying edge computing for distribution automation has the advantage of faster response time. Also, Mr. Melese discussed how data processing, communications, and analytics at edge of grid can better support microgrid formations.


Johan Enslin, Clemson, introduced a new base funded project with NC State, DM-03: Integrated Grid Operations System for Inverter-based Resources. The objective of this project is to utilize grid simulation resources such as RTDS at multiple locations by tying them together to perform co-simulations of T&D systems. Again, the objective is to determine how transmission system events impact DER sites in the distribution system.


Tiefu Zhao, UNCC, introduced the team of UNC Charlotte and Clemson working on PG-03: AI based Arc Fault Detection for PV Systems. Objective of this project is to utilize machine learning and artificial intelligence to accurately identify arc faults in PV systems. The team presented progress to date and plans for future work in this area.


After lunch, Steven Whisenant, Chair CAPER Steering Committee, introduced the 2023 Research Planning Session.


Session VI – 2022 Research Planning Session


The following Break Out groups met to discuss potential research topics in each of the five Research Themes:


Power Delivery Infrastructure and Systems               1 Drew Clarke
Energy Policy, Markets and Economics                     2 Badrul Chowdhury
Data Management, Analytics and Security                3 Klaehn Burkes
Power Generation, Storage, and Integration             4 Ning Lu
Power Utilization and Energy Efficiency                    5 Valentina Cecchi


Break Out Group summaries:


Group 1: Potential research topics –

  • What are minimum data requirements for useful model
  • How can we push interconnection limits, looking beyond only voltage and thermal limits
  • Control systems speed differences – how to make decisions and stacked uses
  • CVR – how is it changing or is there another method?
  • Should we try to make IBRs like synchronous generators or control them differently
  • Keeping bulk system stable while minimizing local impacts
  • Reliable communications without fiber or largescale control without communications
  • Considering diversity factor in EV impacts to the grid


Group 2: Potential research topics –

  • Flexible resources at grid edge and effects on resource adequacy
  • Rate structures to accommodate EV charging including managed charging. Peak will shift over time in future years, e.g. Initially, you might want to charge EVs at a single time. Eventually, you might want to stagger charging times
  • How do you price new (base) loads? What would you charge them?
  • Will there be aggregators (load, EV, DER) for DR? It’s happening in TX with Sunrun, and they also operate in SC. They’re doing solar + storage. What is the interplay between aggregators and the market: adequacy purposes, risk assessment?
  • Demand Response: DR is ‘crushing’ capacity prices. Need an alternative pricing mechanism acceptable to participants. There can also be a disparity between when it is ordered and when it is operational
  • Transactive energy: peer-to-peer transactions may not be happening yet within the utility space
  • Heating networks: Coordination between natural gas and electricity; hydrogen. Being done in China but may be too futuristic for current projects.
  • Tax credits: Impact on achieving zero-carbon.
  • What happens if there is a carbon price?
  • How would response differ from tax credits?
  • Construct algorithm to demonstrate economic equivalence
  • Integrated resource planning – Siting of EV fast chargers. Initial tranche may be relatively low-cost. Cost for additional units could be higher.
  • Will companies, such as trucking, work around delays in utility charging infrastructure? Or will they resort to independent micro grids, possibly temporary, if heavy-duty charging is not available? The companies might not do this if they must forgo subsidies – Not just a problem for Duke Energy, but also for co-ops
  • What are gaps in tools needed for the emerging SEEM?


Group 3: Potential research topics –

  • Build a resiliency matrix
  • Standard inverter response to faults and industry standard for controls response to faults
  • Wide area monitoring response for adaptive control for response to communications loss and load shedding


Group 4: Potential research topics –

  • Develop short-circuit model for energy storage systems, including negative and zero sequence components
  • For protection, mitigate impacts of backfeeding, harmonics, and short-circuit characteristics


Group 5: Potential research topics –

  • Modernizing our understanding of loads and CVR
  • How to better model user behavior and influence it with incentives, education, and policy
  • Can we take users out of the equation?


Steven Whisenant reviewed the Research Solicitation Process with timeline for the official Notice of Intent, and Proposal Submission dates.


Next Meeting – March 27 and 28, 2023 hosted by UNC Charlotte with the theme: Engineering a Regional Hydrogen Hub.


CLOSED MEETING– IAB Members Meeting – Open to all attendees of companies that are Industry Members of CAPER.


The IAB met to elect officers for 2023 and collect feedback on the fall meeting for submission to the CAPER Steering Committee. Drew Clarke, Duke Energy, was elected Chair and Rebecca Rye, Dominion Energy was elected Vice-Chair for 2023. Many thanks to Klaehn Burkes, SRNL, for several years of dedicated service as Chair of the IAB.


Presentations and Project Updates can be found by visiting www.caper-usa.com on the Members Only area of the website.