After an AC fault occurs on the inverter side of the high voltage direct current (HVDC) system

the electrical quantities change dramatically

and controller interactions become complex

resulting in unclear factors affecting subsequent commutation failure (SCF). To address this

this paper conducts an in-depth analysis of the factors affecting SCF based on full-process transient modeling of the system. Firstly

by categorizing the regular commutation process based on the conduction status of valve groups during commutation failure

a comprehensive full-process transient modeling method is proposed

which accounts for the dynamic characteristics of multiple electrical quantities and the influence of the DC control system. Secondly

through the analysis of the phase variation in the AC bus voltage

it is concluded that the firing angle deviation caused by the transient error of the phase-locked loop (PLL) will quickly reduce the current error controller (CEC) output

which is the primary factor causing SCF. Then

the risk level of SCF under various fault occurrence moments is further analyzed from the perspective of the severity of commutation failure. Finally

based on the CIGRE HVDC benchmark system

the proposed transient modeling method and analysis of factors affecting SCF are verified in PSCAD/EMTDC.