2nd China International Youth Conference on Electrical Engineering (CIYCEE 2021)

The renewable energies-dominated power generation revolution and the terminal electrification-dominated energy consumption revolution have been promoting the modern power system marked by high penetration of various converters for power generation, transmission, distribution, and consumption. At the same time, with the gradual change of leading equipment and the associated evolution of power system dynamic characteristics, the safe and stable operation of converter-dominated power systems is facing major challenges, especially the most urgent frequency stability issues. In recent years, several power blackouts caused by frequency events have occurred in many countries. Therefore, there is an urgent need to pay more attention to the frequency stability of the modern power system, and especially to the power converters with frequency-interactive stability.
In this lecture, we will review typical cases of grid frequency events all over the world, summarize technical requirements and development trends of grid codes, and introduce key technologies of frequency-interactive converters actively supporting grid frequency stability by using basic concepts, principles, and methods adopted in power system and power electronics communities. The main contents include a Review of the historical development of power system frequency stability issues, classification of typical frequency-interactive control strategies for converters supporting system frequency stability, comparison of existing technical solutions from the perspectives of technical performance and economic cost, especially introduction of the frequency trajectory planning based converter control strategy that can take into account regulatory requirements of grid code and economic benefits of power producers simultaneously, and finally, a summary of ten key technologies remain to be resolved for frequency-interactive converters actively supporting the grid frequency stability.