ABSTRACT

This research article implemented a new technique for a direct ac to ac power conversion in a three-phase quasi Z-source direct matrix converter (QZSDMC). The QZSDMC is designed by connecting a quasi Z-source impedance network in series with a normal direct matrix converter. In this system, three-phase fixed voltage and supply frequency has been received from the source, whereas the variable ac voltage and frequency are fed to the stand-alone system. The bidirectional operation capability of QZSDMC provides buck-boost action with a minimum number of control switches. Here, the voltage transferring capability is controlled by its shoot-through duty ratio value. Due to the direct duty ratio pulse width modulation technique (without harmonics injection) in QZSDMC, the output voltage is doubled along with variable frequency. However, the discussion is limited here because this technique is used for an odd number of output phases. The increased output voltage from 100 V to 245 V with a minimum amount of harmonics distortions has been observed using MATLAB simulation and the same is experimentally validated. In addition to this, the converter having the capabilities of converting a fixed frequency of 50 Hz into variable frequencies like 25 Hz, 75 Hz and 100 Hz.

摘要

本研究文章在三相准 Z 源直接矩阵转换器 (QZSDMC) 中实现了一种直接交流到交流电源转换的新技术。QZSDMC 是通过将准 Z 源阻抗网络与普通直接矩阵转换器串联连接而设计的。在该系统中，三相固定电压和电源频率已从电源接收，而可变交流电压和频率则馈送到独立系统。QZSDMC 的双向操作能力以最少数量的控制开关提供升降压动作。这里，电压传输能力由其直通占空比值控制。由于 QZSDMC 中的直接占空比脉宽调制技术（无谐波注入），输出电压随着频率的变化而翻倍。然而，此处的讨论受到限制，因为该技术用于奇数个输出相位。使用 MATLAB 仿真已观察到输出电压从 100 V 增加到 245 V，且谐波失真最小，并通过实验验证了这一点。除此之外，转换器还具有将 50 Hz 的固定频率转换为 25 Hz、75 Hz 和 100 Hz 等可变频率的能力。