Flexible DC power transmission converter valve black module detection method

The invention discloses a black module detection method for a flexible direct current transmission converter valve, which comprises valve control and comprises the following steps: step 1, when a sub-module is a normally operating sub-module block, if a bypass switch can be normally closed, it is indicated that the sub-module is successfully bypassed, and the closing number of the bypass switch is reset; step 2, determining that the sub-module is a normal sub-module if the sub-module is a bypass switch closing sub-module before the sub-module, detecting that uplink communication is normal and no bypass switch is closed for 2 ms, and judging that the sub-module is a normal sub-module, and resetting the normal communication count; step 3, if the sub-module is a black module and the bypass switch is detected to be closed for 150ms, judging that the sub-module is a normal bypass sub-module, and resetting the closing count of the bypass switch; and step 4, if it is detected that uplink communication is normal and