Flexible direct current transmission converter station and fault control method

The invention relates to a flexible direct current transmission converter station. The flexible direct current transmission converter station comprises a converter valve, a positive electrode transmission line, a negative electrode transmission line, a direct current breaking device set and two smoothing reactors. The two smoothing reactors are connected with the positive electrode and the negative electrode of the converter valve respectively, and the positive electrode and the negative electrode of the converter valve are connected with the smoothing reactors respectively and then correspondingly connected with the positive electrode transmission line and the negative electrode transmission line through the direct current breaking device set. The invention further relates to a fault control method for the direct current breaking device set of two structures. By the application of the direct current breaking device set, various faults can be effectively removed, and reliability of the flexible direct current transmission converter station is greatly improved.