任先文,王勋,刘雅轩,夏庆生.应用于模块化多电平VSC-HVDC的新技术[J].电测与仪表,2012,49(2):55-59. REN Xian-wen,WANG Xun,LIU Ya-xuan,XIA Qing-sheng.New Technologies in the Application of MMC-VSC-HVDC[J].Electrical Measurement & Instrumentation,2012,49(2):55-59.
应用于模块化多电平VSC-HVDC的新技术
New Technologies in the Application of MMC-VSC-HVDC
This paper presents a novel topology on precharge and step-wave modulation for VSC-HVDC application.Firstly,a traditional precharge process of MMC was modeled in MATLAB,its drawbacks were summarized and a novel topology was proposed based on submodules charged synchronously;Secondly,concerning the drawbacks of traditional PWM modulation technologies,i.e.,SVPWM and SHPWM,an improved staircase waveform modulation control technology based on energy equivalent principle.The proposed modulation technology makes the individual semiconductors have much lower switching frequency,resulting in lower switching losses and the whole process is completely independent of AC system frequency,which can be calculated off-line.The technologies and conclusions are validated by simulations in MATLAB.The theory analysis and simulation results indicate that these new technologies have great potentiality in the application of VSC-HVDC projects in future.