Frequency stability: Nordic system case through the lens of a researcher
Abstract:
Frequency stability is essential for the safe and reliable operation of every power system. It represents a system-level and continuous balance between active power generation and load. To ensure appropriate frequency quality, disturbance rejection, and power dispatch between units in the large system, frequency controllers must be carefully tuned and sufficient power reserves must be maintained at all times. Even more, such power reserves should be distributed in accordance with acceptable cost compensations.
The new projections for the near-future Nordic energy mix indicate substantial integration of inverter-based units and, consequently, system operation under changing inverter shares and, therefore, inertia. An interesting challenge concerns fast frequency control and the role of invert-based units. There are efforts to optimize solutions between the use of associated frequency reserves and stability improvements. Furthermore, with the more pronounced introduction of potentially inverter-based units (e.g., batteries, wind, HVDC, electric vehicles), other implications for system stability can arise. Specific concerns relate to the synchronous generators' ability to synchronize in the presence of large, rapid power injections from inverter-based units. Additional challenges emerge as frequency control becomes more dispersed, including appropriate system-level and component modelling, optimal control, qualification requirements, the choice of dimensioning disturbance, and others that make this problem unique and relevant for the coming period.
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.
Date and Time
Location
Hosts
Registration
-
Add Event to Calendar
- KTH Campus
- Teknikringen 33
- Stockholm, Stockholms lan
- Sweden 114 28
- Building: H-huset
- Room Number: Room 2306 (Ivar Herlitz), Floor 3
- Starts 20 March 2026 11:00 PM UTC
- Ends 08 April 2026 10:00 PM UTC
- 8 in-person spaces left!
- No Admission Charge