A High-accurate Commutation Failure Identification Method for LCC-HVDC System

Line-commuted converter based high voltage direct current (LCC-HVDC) technology has been developed rapidly. Commutation failure (CF) is one of the most common phenomenon in LCC-HVDC systems. To identify the CF fast and accurately to take efficient measures of control system, by analyzing the relationship between the LCC-HVDC commutation voltage and arm current during the commutation process, this paper proposed a new CF identification method based on commutation voltage and arm current. During the specified sampling time, if the commutation failure factor KCF is positive, it can be judged that the CF occurs. Simulation results show that the proposed method can identify the CF effectively and it is simple and easy to apply in engineering practice.