MMC变流器模块电压波动对输出电压的影响  

Effects of the module voltage fluctuation on the output voltage of modular multilevel converter

作　　者：雷鸣[1] 李耀华[1] 葛琼璇[1] 王晓新[1] 

机构地区：[1]中国科学院电工研究所电力电子与电气驱动重点实验室,北京100190

出　　处：《电机与控制学报》2014年第3期25-33,共9页Electric Machines and Control

基　　金：国家高技术研究发展计划(863计划)(2011AA050404)

摘　　要：为了研究模块化多电平变流器(modular multilevel converter,MMC)模块电压波动对输出电压的影响,建立了MMC的数学模型,忽略调制算法引起的高次谐波,推导了变流器输出电压的解析表达式,并针对MMC变流器实际应用过程中常采用的谐波抑制算法,简化了变流器输出电压表达式。分析表明,MMC变流器模块电容电压波动将会在输出电压中引入奇次谐波,同时将使得输出电压实际值与给定值之间出现偏差。为了度量偏差大小,定义了模块电容电压波动系数,并证明偏差大小取决于模块电容电压波动系数与输出电压调制度的比值。为了使得变流器能够正常工作,该比值应控制在一定范围以内。仿真实验的结果证明了理论推导与分析的正确性。In order to research the effects of the module voltage fluctuation on the output voltage of modular multilevel converter （MMC） , the mathematical model of modular multilevel converter （MMC） was established and the analytical expression of the converter＇s output voltage was deduced on the condition that high frequency harmonics caused by modulation algorithm was neglected. And for the circulating current restraint control method which was often used, the expression of output voltage was simplified. The analysis shows that caused by the fluctuation of module capacitor voltage, there are odd harmonics in the output voltage. Moreover there is a deviation between the actual value and the reference value of the output voltage. In order to measure the value of the deviation, fluctuation coefficientof module capacitor volt- age is defined, and it may draw a conclusion that the deviation is depended on the ratio of the fluctuation coefficientto the modulation degree of output voltage. To make sure that the converter can work properly, the ratio should be limited in a certain range. At last, experiment results demonstrate the validity of the theoretical derivation and analysis.

关 键 词：模块化多电平 数学模型 谐波分析 模块电容电压波动系数 输出电压 

分 类 号：TM464[电气工程—电器]