Taxonomy of Power Converter Control Schemes based on the Complex Frequency Concept

This paper proposes a taxonomy of power converter control schemes based on the recently proposed concept of complex frequency. This quantity captures local frequency variations due to the change of both the phase angle and amplitude of bus voltages and current injections. The paper derives the analytical expressions of the link between complex power variations and complex frequency of each converter controller as well as the identification of critical control parameters. The main contribution of this work is to provide a general framework that allows classifying converters synchronization mechanisms and controllers. This framework also allows comparing converters with synchronous machines. To validate the theoretical results, extensive simulations are performed using a modified version of the WSCC 9-bus system. Examples of how the theoretical formulations of the paper can be used to improve power converter control in power system applications are showcased.

Acknowledgement

This work is partly supported by the Community of Madrid, research project PROMINT-CM (P2018/EMT4366), and Juan de la Cierva Incorporación program (IJC2019-042342-I) from the Spanish Government by funding D. Moutevelis, J. Roldán-Pérez and M. Prodanovic and by the Sustainable Energy Authority of Ireland (SEAI) by funding F. Milano under project FRESLIPS, Grant No. RDD/00681.