Comprehensive review of commutation failure in HVDC transmission systems.

• An overview of state-of-the-art commutation failure (CF) is provided. • A review of the impact of multi-infeed structure on CF is undertaken. • The advantages and limitations of different CF prevention methods are examined. • Suggestions and potentially important future research directions are put forward. [Display omitted] Commutation failure (CF) is the main fault type in high voltage direct current (HVDC) systems with line commutated converters. To mitigate CFs, considerable researches have been done either in modelling or control methods. However, with the operation of more and more large-capacity HVDC projects, the coupling characteristics between HVDC and power grid are more complex. The existing reviews tend to focus only on the CFs of a single HVDC itself. This paper provides a more systematic overview of CFs, covering fifteen specific aspects in six areas, including four types of system structures, such as multi-infeed HVDC, and various types of CFs. The mechanism, discrimination, modeling, and prevention of CFs are reviewed extensively in combination with the latest literature. In particular, the advantages and limits of various CFs prevention methods are analyzed and compared in order to reveal the latest research results. Finally, it points out that the analysis and control of multi-infeed HVDC and hierarchical infeed HVDC, the application of artificial intelligence (AI) technology, the improvement of communication-based on 5G technology, harmonic problems, and control and coordination strategies of new auxiliary equipment are challenges and research directions of HVDC CFs in the future. [ABSTRACT FROM AUTHOR]