The Nordic Power System in the Fossil-Free Transition: Insights from Ongoing RISE Research

Seminar abstract:

Power systems worldwide are experiencing steadily increasing electricity demand. Meeting this demand with fossil-free solutions while maintaining safe, stable, and reliable system operation represents a major challenge. One approach is to develop a diverse generation portfolio that combines renewable resources such as wind and solar with low-carbon conventional sources such as nuclear and hydropower.

Large-scale integration of inverter-interfaced components offers significant opportunities to improve system stability and resilience. However, inverters also have limitations that can alter system dynamics and established control and operation paradigms. While inverters provide flexible control and fast response, they can also reduce the system's strength, making it more prone to control interactions that may lead to severe oscillations. Therefore, increasing inverter penetration and applying new solutions must be carefully managed to avoid adverse effects on the stability and operation of large conventional power plants.

The seminar will introduce several ongoing projects led by RISE tackling the above-described challenges relevant to the Nordic power system. Among others, the ones presented in more detail are:

• (NU-ACTIS) Navigating Uncertainties: Advanced Control Solutions for Inverter-Dominated Power Systems, CETP-funded

• Black-start and island operation of wind farms in Sweden – Pre-study and initial analysis, SWC-funded

• Nuclear generator behavior under the grid’s forced oscillations, Energiforsk/GINO-funded

Speaker Bio:

Danilo Obradović is a researcher at RISE Research Institutes of Sweden AB in the Electric Power System unit, focusing on power system stability, control, and modelling at various levels of integration of inverter-based resources. He obtained a PhD from the Electric Power and Energy Systems division at EECS, KTH Royal Institute of Technology in Stockholm, Sweden, and an MSc from the Department of Power Systems at EECS, University of Belgrade, Serbia. He has previous experience working on commercial and customer-facing projects through various system studies as an HVDC control design and simulation engineer at Hitachi Energy Sweden AB. Danilo has developed expertise in frequency and small-signal stability, having been involved in several research projects and the publication of scientific articles. He is currently co-leading research projects assessing converter-driven instability, black-start and islanding operation using wind power, and the impact of forced oscillations on nuclear power plants. He is an IEEE and CIGRE member.