Review of Commutation Failure on HVDC Transmission System Under Background of Multi-infeed Structure

The rapid development of multi-infeed HVDC transmission projects has met the increasing demands for energy transmission to a certain extent. However, the increase of the DC drop points make the coupling characteristics of the AC-DC hybrid power system more complicated, and the problem of commutation failures is particularly prominent. This paper elaborates on the commutation failure problem in the multi-infeed HVDC system, analyzes the influencing factors of the commutation failures in the multi-infeed HVDC system. It introduces the commutation failure judgment and risk assessment methods in the multi-infeed HVDC system, and compares their similarities and differences. The suppression measures for multi-infeed HVDC commutation failures are summarized, and the engineering-level research conclusions based on the actual multi-infeed grid model simulation are listed. Finally, it points out that the practical engineering analysis of harmonic factors, the coupling effect analysis in layered and multi-terminal single-layer structure, and the applicability expansion of commutation failure suppression measures in the multi-infeed HVDC systems are the key issues in the future research field of commutation failures of multi infeed HVDC systems. Taking the multi-infeed structure as the breakthrough point, this paper comprehensively expounds the characteristics of the HVDC system commutation failure problem under the background of the multi-infeed structure from the perspective of its definition, analysis, and control. © 2022, Power System Technology Press. All right reserved.