Z-source inverters (ZSIs) are recent solutions for single-stage power conversion with boosted dc rail voltage. Trans-ZSI, employing a coupled inductor, allows high boost with lower shoot-through duty ratio. Albeit the several advantages, these converters exhibit unsatisfactory performance at low power factor due to discontinuous current conduction modes—a major concern in applications like motor drives at light loads. The objective of this article is to develop an improved Trans-ZSI with multilevel output voltage that performs well irrespective of load power factor. The proposed topology has continuous input current, low input current ripple, and the presence of active switches in the impedance network allows bidirectional current flow. Also, there is output voltage control flexibility by adjusting the coupled inductor turns ratio, shoot-through time, and modulation index. Partial shoot-through states allow nearest three vector switching for obtaining multilevel output voltage and reduced dv/dt. The output stage retains all the advantages of active-neutral-point-clamped (ANPC) inverter. Operating principles, analysis and a ‘simple boost control’ with carrier-based space vector pulse width modulation (CSVPWM) scheme for capacitor balancing are presented. Simulation and hardware results on three-phase, 3 HP, 220 V, 1440 rpm, V/f-controlled induction motor drives are presented to validate the proposed scheme.

中文翻译：

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改进的 Trans-Z 源有源中性点钳位多电平逆变器，具有用于感应电机驱动的连续输入电流


Z 源逆变器 (ZSI) 是具有升压直流轨电压的单级功率转换的最新解决方案。 Trans-ZSI 采用耦合电感器，可实现高升压和较低的直通占空比。尽管有几个优点，但由于不连续电流传导模式，这些转换器在低功率因数下表现出不令人满意的性能，这是轻负载电机驱动等应用中的一个主要问题。本文的目标是开发一种改进的 Trans-ZSI，具有多级输出电压，无论负载功率因数如何，其性能都良好。所提出的拓扑具有连续输入电流、低输入电流纹波，并且阻抗网络中的有源开关的存在允许双向电流流动。此外，通过调整耦合电感器匝数比、直通时间和调制指数，可以灵活地控制输出电压。部分直通状态允许最近的三矢量切换以获得多级输出电压并降低 dv/dt。输出级保留了有源中性点钳位 (ANPC) 逆变器的所有优点。介绍了工作原理、分析以及用于电容器平衡的基于载波的空间矢量脉宽调制 (CSVPWM) 方案的“简单升压控制”。三相、3 HP、220 V、1440 rpm、V/f 控制感应电机驱动器的仿真和硬件结果旨在验证所提出的方案。