The invention discloses a method for starting
hybrid MMC (Modular Multilevel Converter) including full-bridge submodules, and belongs to the technical field of flexible high-
voltage direct-current
power transmission. The method comprises an uncontrolled charging stage and a controlled charging stage, wherein at the uncontrolled charging stage, all the submodules are locked, and capacitors in the submodules are charged by an alternating-current
power grid. At the end of the uncontrolled charging stage, the controlled charging stage is entered, a current converter is unlocked, a closed-
loop control loop is added to control submodule switch tubes, and submodule capacitors are further charged to a rated
voltage. A starting process is finished when voltages of all submodule capacitors reach therated
voltage and a direct-current side voltage reaches a rated direct-current
bus voltage. By adopting the method, the current converter is controlled to run under an increased voltage at the controlled charging stage by means of the negative level output capabilities of the full-bridge submodules, so that an alternating-current side output voltage is increased;
impact current of the alternating-current
power grid in a charging process is reduced; a current-limiting
resistor is switched off under low current; and influence on the service life of a power device is avoided.