基于直流储能的15电平混合级联变换器调制策略比较  

Comparison among Modulation Strategies for 15-level Hybrid Cascaded Converter Powered by DC Energy Storage

作　　者：周思璇 ZHOU Sixuan(State Grid Hubei Electric Power Company Economic ＆ Technology Research Institute,Wuhan 430077,China)

机构地区：[1]国网湖北省电力有限公司经济技术研究院,武汉430077

出　　处：《电源学报》2018年第4期43-51,共9页Journal of Power Supply

摘　　要：多电平级联变换器由H桥子模块串联而成。将3个H桥子模块级联而成的传统级联7电平变换器的直流储能供电电压之比从1:1:1改为4:2:1,可得到一种改进版基于直流储能的15电平混合级联变换器。针对此调制策略进行研究,提出了一种新的适用于由直流储能装置供电的多电平变换器开关角度的算法。基于Saber仿真软件,分别应用阶梯波调制、PWM以及部分PWM 3种不同的调制策略进行验证和比较。最终,基于不加任何滤波器的输出电压总谐波失真、低次谐波分量以及该变换器开关损耗方面的仿真结果进行了对比,并对相应的调制策略进行了探讨。A multi-level cascaded converter consists of H-bridge sub-modules in series. Similarly, a conventional 7-level cascaded converter is composed by three H-bridge sub-modules, and when the voltage supply ratio of its DC energy storage units is changed from 1：1：1 to 4：2：1, an improved 15-level hybrid cascaded converter can be obtained. The modulation strategies for this 15-level cascaded converter are studied, and a novel algorithm for calculating the switching angles is proposed, which is suitable for a multi-level converter powered by DC energy storage units. Based on a simulation software Saber, verifications and comparisons are conducted under three different modulation strategies, i.e.,staircase modulation, PWM, and partial PWM. Finally, comparisons are performed based on simulation results of the total harmonic distortion of output voltage without any filter, the lower order harmonic components, and the switching loss of the proposed converter; meanwhile, the corresponding modulation strategies are also discussed.

关 键 词：混合级联多电平变换器 阶梯波调制 脉宽调制(PWM) 部分PWM 谐波 

分 类 号：TM921.52[电气工程—电力电子与电力传动]