Dominant Device Identification in Multi-VSC Systems by Frequency-Domain Participation Factor

With fast development of power electronic technology, the power system is undergoing a great revolution to a power-electronic-based one and it poses a great challenge to the dominant device identification for the system stability analysis. As an alternative approach, this paper proposes a frequency-domain participation factor method based on the open-loop transfer function matrix of power imbalance model. It also clarifies the relation between different (time-domain, frequency-domain closed-loop, and frequency-domain open-loop) participation factor analytical methods, showing that they are all certain sensitivities against parameter disturbance on different matrix elements. Furthermore, by using this method we study the classical IEEE 10-generator-39-bus system where the synchronous generators are completely replaced by grid-following or grid-forming converters and show that the system stability can be improved by modifying the corresponding parameters of the identified dominating converter.