According to operating experience of HVDC transmission project

commutation failure in inverter station

which is mostly caused by AC system fault

will also be caused by AC filter switching-on. This paper

referring to the commutation failure cases happened in Guangzhou converter station of Tian-Guang HVDC project and to study the record of transient fault recorder

is to prove that AC filter switching-on at a wrong timing is the cause of the incidents. By testing the discreteness of motion of the AC filter circuit breaker in Guangzhou converter station

the result of switching-on at a wrong timing is caused by the incoordination between circuit breaker and phase-selecting device. By using the RTDS model of Gui-Guang II Line HVDC project for simulation

AC filter switching-on at a wrong timing will cause the commutation failure or not

is relative to the AC system strength of inverter side of HVDC system. Base on the summary and analysis of the reason of commutation failure

the improvement and further research suggestion is given.