3×4矩阵变换器

3×4 matrix converter

针对3×3矩阵变换器(MC)不能带非平衡负载的问题,提出一种新型的MC,其拓扑结构在传统的3×3 MC的基础上,增加了一中线桥臂N连接到负载的中性点,构成3×4 MC。建立了3×4 MC的等效交-直-交拓扑,并分析了原拓扑与等效拓扑开关之间的对应关系。对等效拓扑中的整流级采用二维电流空间矢量调制,为逆变级提供一直流电压。介绍了三维电压空间矢量的调制原理,并通过对逆变级拓扑的分析后,将三维电压空间矢量用于逆变级的调制,便可以在负载上产生所期望的电压。将整流级和逆变级的调制进行整合,就可以得到3×4 MC的控制策略。应用Matlab/Simulink进行了仿真,结果表明:在平衡或非平衡负载情况下,3×4 MC及其控制策略都可以输出理想的三相对中线的对称电压波形。

For unbalanced load, 3×4 MC（Matrix Converter） is proposed, which is based on 3 ×3 MC with an added neutral bridge connecting to the neutral point of load. Its equivalent AC/DC/AC topology is established and the relationship of switches between the original topology and the equivalent topology is analyzed. The rectifier is modulated by the two-dimensional current space vector modulation for the DC voltage of inverter while the inverter is by modulated the three-dimensional voltage space vector modulation for the expected voltage of load. The control strategy of 3 × 4 MC is achieved by integrating the modulations of rectifier and inverter. Simulation results show that, under the 3 × 4 MC control strategy, three-phase symmetrical line voltages are obtained under both balanced and unbalanced load conditions.