一种新型的矩阵变换器间接调制策略

A Novel Indirect Modulation Strategy of Matrix Converter

基于传统的矩阵变换器间接空间矢量调制思想,提出了一种利用输入电压瞬时值合成虚拟整流输出电压的策略,使矩阵变换器在非正常输入时期望的虚拟整流输出电压平均值仍能维持不变.着重对虚拟整流环节进行了分析,给出了具体的调制算法,并通过综合虚拟整流及虚拟逆变环节,得到了矩阵变换器占空比的计算公式.仿真及实验结果表明:所提出的调制策略,不但使矩阵变换器在理想输入时具有良好的输入、输出性能,且非正常输入时输出电流波形质量也较好,其THD值为2.4%;而相同条件下传统的间接空间矢量调制策略,其THD值为12.89%.新的调制策略能有效地抑制非正常输入引起的输出电压谐波.

A novel modulation strategy of matrix converter was proposed based on traditional indirect space vector modulation strategy. The input voltage instantaneous value synthesis method was adopted in the virtual rectifying process, which kept the average value of the expected virtual rectifying output voltage steady even if the input voltage was unbalanced and distorted. The virtual rectifying process was mainly analyzed, a concrete modulation algorithm was given, and a duty cycle formula was gained by integrating virtual rectifying processed and inverting process. The results show that matrix converter possessed good input/output performance in ideal input voltage, and good output performance even though in abnormal input. The input current THD is about 2.4%. Under the same parameters, the input current THD with the traditional indirect space vector modulation strategy is 12.89%. The output voltage harmonics brought by the abnormal input voltage is restrained effectively using the proposed control strategy.