Study on commutation failure of multi-infeed HVDC system

Commutation failures (CF) are very frequent dynamic events in HVDC system. A new issue arising in a multi-infeed HVDC system is whether or not all the inverters will suffer from commutation failures simultaneously. In response to different AC system disturbances, an electromagnetic transient simulation study of commutation failure based on a dynamic dual-infeed HVDC test model has been carried out in this paper. The analysis of the causes leading to commutation failures in a multi-infeed HVDC system, specifically of the voltage reduction and phase shift is given. The effect of the coupling impedance in the dual-infeed test model on the simultaneous commutation failures is also discussed.