Thyristor-based Modular Cascaded Converter Topology and Its Coordinated Control Strategy
To completely solve the problem of commutation failure of line-commutated converter based high voltage direct current(LCC-HVDC),a thyristor commutation module with controllable output voltage and adjustable impedance during commutation is proposed,and a novel converter topology which can completely resist commutation failure is constructed by its cascade.The fixed trigger timing of the thyristor without additional fault detection and the automatic switching mode of the commutation module according to the running state of the system is presented.The coordinated control strategy between the commutation current module and the valve arm and the parameter design method of the components in the commutation module are proposed.Finally,the analysis and verification is carried out in PSCAD/EMTDC,and the results show that the proposed novel converter can not only completely solve the problem of commutation failure,but also maintain a certain level of power transmission capacity even during the fault.The proposed parameter design method is reasonable,and the stress of the converter module components is within the design allowable range.
line-commutated converter based high voltage direct current(LCC-HVDC)commutation failurethyristor converter modulenovel converter
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维普
