Valve base control device and method for modular multi-level convertor

A valve base control device and method for a modular multi-level convertor (4). The modular multi-level convertor (4) is provided with a bridge arm comprising a plurality of cascaded submodules. The valve base control device comprises the following components constructed in a hierarchical control architecture: a current control unit which is used for realizing the current control of a convertor and the real-time generation of the input number of bridge arm submodules, acquiring the current direction of the bridge arm, and sending number information and current direction information; a bridge arm collection control unit which is used for determining submodules to be input or cut out according to the received state of each submodule and the number information and the current direction information which are received from the current control unit, and sending a determination result; and a bridge arm subsection control unit which is used for realizing the input or cut out of each submodule according to the determination result received from the bridge arm collection control unit, and acquiring the state of each submodule and sending same to the bridge arm collection control unit. The above-mentioned hierarchical control architecture disperses the functions of the valve base control device for a convertor to a plurality of hardware devices, so as to reduce the load of a single hardware device.