Simulation analysis of commutation failure in a multi-infeed HVDC system

This paper provides a detailed simulation of commutation failures in line-commutated thyristor converters. Theoretical analysis of commutation failure is presented. Influencing factors (such as voltage drop, voltage decreasing velocity, phase shift over zero of commutation voltage, HVDC controller) of both AC system and HVDC system on commutation failure are discussed in this paper. Then improvement of the characterization of the firing angle control is used to avoid commutation failure. Theory validation by simulation is also given.