Analysis on commutation failure caused by AC faults in multi-infeed HVDC systems

Commutation failure (CF) is one of the common faults in HVDC system, a new issue arising in multi-infeed HVDC systems is whether all the inverters will suffer from commutation failures concurrently, and the interaction between AC and DC systems is much more complicated. According to the mechanism of commutation failure, influencing factors and judgment basis, this paper proposed a commutation failure detection method based on the critical multi-infeed interaction factor (CMIIF). A three-infeed HVDC system was modeled in PSACD/EMTDC, The simulation results of the test system and an actual system proved the accuracy and validity of the proposed method.