Capacitor voltage balance control method based on bundling type switching of multiple sub modules

The invention provides a capacitor voltage balance control method based on bundling type switching of multiple sub modules. By means of a bundling mode, the quantity level of the sub modules of a modularization multi-level converter valve is degraded for one level, lowering of the capacitor voltage balance control calculated amount is facilitated, and the requirements for control equipment are lowered. After the sub modules are bundled into a module group, switching is conducted overall, the voltage balance of the sub module group is achieved by using a capacitor voltage balance algorithm, voltage-sharing is achieved on the inner portion of the sub module group through self-adaptation, and total voltage-sharing of the sub modules can be achieved. By means of the capacitor voltage balance control method based on bundling type switching of the multiple sub modules, the problem of the control of a high-capacity voltage source converter based high voltage direct current converter valve based on a modularization multi-level converter mode can be effectively solved, and controlling and monitoring of the converter valve with large-scale amount can be achieved.