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

TL;DR

This paper introduces a new taxonomy for power converter control schemes based on complex frequency, providing a unified framework for classification, comparison, and enhancement of control strategies in power systems.

Contribution

It develops a comprehensive framework using complex frequency to classify and compare power converter control schemes and their synchronization mechanisms.

Findings

Framework successfully classifies various control schemes

Analytical expressions link power variations to complex frequency

Simulations validate theoretical predictions

Abstract

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.