Historically, transmission (T) system and distribution (D) system analysis has been done separately. The main reasons are 1) different... Show moreHistorically, transmission (T) system and distribution (D) system analysis has been done separately. The main reasons are 1) different modeling frameworks, i.e., positive-sequence versus three-phase unbalanced, 2) system size, and 3) lack of dynamic two-way interaction between T&D. The typical power system usually consists of tens of thousands of transmission buses and thousands of distribution feeders with hundreds of customers per feeder. In the past, distribution networks have been largely passive with relatively little dynamic interaction with the transmission network. However, due to the new trends that the electric grid has been witnessing in the last decade with the installation of distributed energy resources (DERs) on the distribution level, such as behind-the-meter generation and energy storage units, electric vehicles, etc., dynamic simulation tools for combined T&D will become necessary in the near future. These tools will aid system operators and planning engineers in understanding the impact of these new trends on large-scale power systems. Taking advantage of the advancements in the field of high performance computing and parallel computing could enable accurate, wide-area T&D dynamics simulation. These comprehensive simulation capabilities would dramatically improve our ability to predict the complex interactions among DERs, customer loads and traditional utility control devices, thereby allowing higher penetrations of renewable energy, electric vehicles and energy storage. Show less
