Dynamic modelling for distribution grid analysis in the time domain

With the proliferation of renewable energy sources such as solar and wind power, distribution systems are facing unprecedented challenges due to the intermittent and variable nature of these energy resources. To address this escalating complexity, appropriate analytic approaches are necessary to facilitate the integration of renewable energy sources. In this evolving landscape of electrical power systems, dynamic simulation in the time domain has become increasingly important for the analysis of distribution systems. Such simulations consider time-varying phenomena and transient events, that are essential for a comprehensive understanding of the behavior of distribution grids under changing conditions. This chapter presents the importance of dynamic simulation in the context of power system stability and reliability, with a focus on distribution system operation. Basic information on modeling the energy system in the time domain is presented and several generic models, including conventional power plants, DERs and energy storage systems, are described. The chapter not only provides a basic understanding of dynamic modeling on different time scales and the difference between RMS and EMT simulations, but also contains relevant references for interested readers who need further guidance in the field of dynamic simulation of electrical power systems. A case study on the provision of ancillary services in an island grid with high DER feed-in, utilizing some of the previously described modeling approaches, completes the chapter.