摘要
简述模块化多电平变流器的应用和阶梯波调制的优点;分析采用基于拉格朗日乘子的阶梯波调制算法的原理,指出算法对多电平计算的优势,叙述利用牛顿-拉尔逊法实现该阶梯波计算的过程;计算阶梯波算法的调制范围,利用傅立叶分析对输出电压的谐波含量进行分析,确定调制比的合理范围;针对调制范围较窄的缺陷,提出用不同电平的阶梯波和多重载波混合调制的控制策略;通过对7电平的变流器的无功功率变化和低电压穿越进行仿真,对混合调制策略进行了验证;最后得出结论混合调制在提高模块化多电平变流器控制能力方面有显著效果。
This paper briefly describes the application of modular multi-level converters and the advantages of step wave modulation,analyzes the principle of step wave modulation algorithm based on the Lagrange multiplier,and points out the advantages of the algorithm over the multi-level calculation. It demonstrates the process of implementing the step wave calculation in the Newton-Larsson method,calculates its modulation range,and analyzes the harmonic component of the output voltage in the Fourier analysis method to determine the modulation range reasonably. Furthermore,in view of the disadvantage of narrow modulation range,it presents a control strategy using hybrid modulation of step waves of various levels and multiple carriers. The hybrid modulation strategy is verified through simulation of changes of the reactive power and low-voltage ride through of the 7-level converter. Finally it is concluded that hybrid modulation can remarkably improve the control ability of the modular multilevel converter.
出处
《电气自动化》
2015年第6期14-17,共4页
Electrical Automation
基金
上海市科委科技攻关计划(13dz1200401)
关键词
模块化多电平变流器
阶梯波混合调制
拉格朗日乘子
傅立叶分析
低电压穿越
modular multi-level converter
step wave
hybrid modulation
Lagrange multiplier
Fourier analysis
low-voltage ride through
