Unidirectional power hybrid MMC and control for startup and DC short circuit fault ride-through
In the scenario of unidirectional power transmission,the coordinated control space of full-bridge submodule(FBSM)and half-bridge submodule(HBSM)inside the bridge arm is explored,and the device-saving semi-half-bridge submodule(SHBSM)and a new unidirectional power hybrid MMC composed of SHB-SM and FBSM are proposed.Aiming at the potential issues of capacitor voltage imbalance,voltage stress and current stress during the startup stage and DC short circuit fault ride-through stage,a startup strategy suitable for the topology is proposed.A DC short circuit fault ride-through control strategy based on DC circulating current injection is proposed to ensure reliable operation of the equipment in the whole opera-tion area.A simulation model based on MATLAB/Simulink is built to verify the feasibility and effective-ness of the proposed control strategy.Compared with the existing hybrid MMC,the proposed topology saves one switching device inside the HBSM while ensuring DC short circuit fault ride-through capability,and has a good cost advantage.
unidirectional powersemi-half-bridge submodulehybrid MMCcoordinated controlstartup strate-gyDC short circuitfault ride-through
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维普
