双级矩阵变换器的过调制策略

针对双级矩阵变换器常规调制策略电压传输比低的问题，在不改变双级矩阵变换器拓扑结构的前提下，该文提出了一种可以提高电压传输比的双级矩阵变换器调制策略。该调制策略将双级矩阵变换器分为两级控制：整流级采用常规电流空间矢量合成法；逆变级根据电压传输比的不同要求将电压空间矢量调制区域分为线性调制区和过调制区。根据过调制程度要求的不同,又将过调制区域分为过调制区域Ⅰ和过调制区域Ⅱ，各个区域分别采用不同的调制模式控制逆变级的输出。论文从理论上分析了过调制策略的原理。仿真和实验结果表明, 双级矩阵变换器过调制时输出电压基波可以精确控制，谐波畸变率比较小，输入输出电流波形质量好。

Analysis of the Overmodulation Strategy for Two-stage Matrix Converter

Aim to the low voltage transfer ratio problem of the conventional modulation method, a modulation method to enhance voltage transfer ratio of dual stage matrix converter is proposed without changing the topology. The proposed control method is divided into two control stages. Conventional current space vector modulation (SVM) is used for rectifier stage. In inverter stage, a two-level control, linear modulation level and over-modulation level, is used according to different required voltage transfer ratio. The over-modulation level is combined with two over-modulation sections, over-modulation section I and over-modulation section II, both of which are implemented by different inverter stage modulation methods. Over- modula- tion is theoretically analyzed. Simulation and experimental results demonstrate that the output fundamental voltage can be accurately controlled with small total harmonic distortion and good input/output current quality.