The U.S Department of Energy’s (DOE) Office of Electricity (OE) hosted a dynamic load modeling workshop to review current related projects on March 24, 2022. The workshop highlighted and gathered feedback on OE research with respect to dynamic load modeling and built community among researchers and with industry.
Dynamic load modeling is a specialized means for representing the short-term (less than one minute) behavior of end-use loads in simulation-based transient stability studies of electric power systems. The models describe how loads respond to physical disturbances that affect the reliability of the power system. Use of dynamic load models is a requirement for planners who conduct these studies pursuant to North American Electric Reliability Corporation (NERC) reliability requirements.
Dynamic load modeling differs considerably from other forms of load modeling. For example, load forecasting models focus on predicting how loads on the power system might evolve over decades, years, seasons, days, or hours of one day. Over these time frames, consideration of changing demographic, economic, and meteorological factors is essential because they impact the resulting forecast directly. These are important, but not the focus of this workshop.
The workshop featured strong and broad participation from DOE, the National Labs, academia, and industry with over 120 registered participants. It opened with keynote presentations by Michael Pesin, Deputy Assistant Secretary for the Advanced Grid R&D program in DOE’s Office of Electricity and by Dmitry Kosterev, Senior Transmission Planner for the Bonneville Power Administration.
The first paper session featured presentations by Soumya Kundu, PNNL, on Harmonic Enhanced Load Modeling and Data Generation and by Nan Duan, LLNL, on Load Sculptor: Robust Dynamic Load Modeling and Uncertainty. Two, invited discussants - Song Wang, Transmission Planning, Pacificorp and Scott Hinson, Chief Technology Officer, Pecan Street - then provided industry perspectives on the papers.
The second paper session featured presentations by Joe Eto, LBNL, on Distribution-level Impacts of Plug-in Electric Vehicle Charging on the Transmission Grid during Fault Conditions, and Dave Chassin, SLAC, on Advanced Load Modeling. Two, invited industry discussants - Kannan Sreenivaaschar, Transmision Planning, ISO New England and Parag Mitra, EPRI - then provided industry perspectives on the papers.
New, rapidly growing electric loads (e.g., EV and heat pumps) and sources (e.g., DER, PV, and storage) require development of dynamic load models so that their reliability impacts on the grid can be assessed accurately and, if needed, to support the development of measures to address any negative impacts.
Access to real-world data is needed to confirm the insights from initial research studies conducted using simulations of toy-size systems. For example, real-world data (e.g., at the substation level) is needed to “train” machine learning approaches for characterizing the dynamic behavior of loads, especially EVs and DERs.
The importance of improving our understanding of and taking better account of power quality and harmonics in transmission planning is growing.
Transmission planners seek dynamic load modeling improvements that:
- Reduce the size of models in order to reduce the computation times required to run models with more sophisticated dynamic load models;
- Improve dynamic load modeling of power electronic loads;
- Improve the characterization of the dynamic behavior of distribution systems;
- Enable more detailed study of the dynamic impacts of load in “weak” transmission systems (e.g., those with significant amounts of inverter-based generation compared to traditional synchronous generation), especially to study the reliability impacts of wildfires and climate change; and
- Enable more detailed studies of synthetic inertia, droop control, etc. These studies should seek to improve our understanding of how the behavior of these devices affects the reliability of transmission systems and their interaction with distribution systems.
There is a need to begin development of standards or other means for ensuring future loads will be “grid friendly.” Conversations and engagement between transmission planners their manufacturing industry counterparts (eg. EV OEMs) will help improve dynamic load models and discuss standards for grid-friendly load-consuming equipment. DOE, through the transmission reliability and resilience (TRR) program, supports standards development through collaboration with industry, academia, and the National Labs. Additionally, the TRR program at DOE plays a role in developing modeling tools, including dynamic load modeling methods, to help accelerate innovation. This workshop will help inform future TRR program development in the area of dynamic line rating, and guide future collaborations with key stakeholders.