CONTROL METHOD AND APPARATUS FOR HIGH-VOLTAGE, DIRECT CURRENT FIRST COMMUTATION FAILURE IN ALTERNATING-CURRENT FAULT

A method, an apparatus and a device for suppressing a first HVDC commutation failure under an AC system fault are provided. The method includes: obtaining a three-phase voltage of a converter bus, and calculating a zero-sequence component amplitude and an αβ component amplitude; calculating a first trigger-angle command for a single-phase fault and a second trigger-angle command for a three-phase fault selecting a smaller one of the first trigger angle command and the second trigger angle command as a trigger-angle command for an extinction-angle controller; and adjusting a trigger angle of the HVDC transmission system by using the trigger-angle command as an upper limit value for an output of the extinction-angle controller of the HVDC transmission system.