A review on evaluation and improvement methods for commutation failure resistance ability in multi-infeed direct current system

The evaluation and improvement methods for commutation failure resistance ability in multi-infeed direct current (MIDC) system are of great significance for testing commutation failure characteristics, addressing assessment challenges, and applying commutation failure defense technology in power system planning and operation. Therefore, a systematic and scientific summary and generalization are conducted in this paper. Firstly, the fundamental definitions of MIDC system and commutation failure are presented, analyzes the impacts of various fault types on commutation failure, identifies key influencing factors, and summarizes existing commutation failure criteria. Secondly, the existing evaluation methods of commutation failure resistance ability are also reviewed. Then, the current improvement methods of commutation failure resistance ability in MIDC system are summarized from three aspects: reactive power compensation optimization, control and protection optimization, and converter topology improvement. Finally, the key issues that need to be focused on in the future mainly include: adopting a normalized effect evaluation method, conducting repeatable calibration on a simulation platform with standard significance, forming a systematic and comprehensive improvement method for the commutation failure resistance ability in MIDC system, and establishing a multi-level coordinated enhancement strategy encompassing converter station level, converter level and system level.