摘要
给出了一种用于桥臂交替导通型多电平换流器的晶闸管换向方法。当换向开关门极信号发生变化时,不立即改变所对应子模块组的输出电压,而是继续保持输出电压以强迫串联晶闸管关断,即通过延迟桥臂交替控制晶闸管作为换向开关。该方法的优点在于:损耗低、直流侧故障耐受能力强,保证换流器具有电压源换流器的灵活性,避免了大量IGBT串联,大幅降低了换流器的实现难度和成本。建立了三相35 kV的240子模块换流器的仿真模型。仿真结果表明:给出的方法可以控制晶闸管关断换向,换流器能够四象限稳定运行,并在此过程中保持桥臂电抗尖峰电压和子模块电压波动均处在合理水平。
A thyristor-switch strategy of A2MC（Alternate-Arm Multilevel Converter） is proposed. When the gate signal of changeover switch changes,the output voltage of corresponding submodule is kept to force the series thyristor to turn off,i.e. taking the delayed arm alternation as the changeover switch to control the thyristor,which has following advantages：low loss,strong DC-side fault blocking capability,the same flexibility like voltage source converter,avoided mass series IGBTs and greatly reduced implementation complexity and cost. A simulation model of three-phase 35 kV 240-submodule converter is built and the simulative results show that,the thyristor-switch can be turned off by the proposed control strategy,the converter can operate stably in four quadrants,and the peak voltage of arm reactor and voltage ripple of submodule capacitor are kept at reasonable level.
出处
《电力自动化设备》
EI
CSCD
北大核心
2015年第1期30-35,共6页
Electric Power Automation Equipment
