ABSTRACT This paper presents a new control scheme for the ac-dc-ac nine-switch converter (NSC) with induction motor operated at constant frequency. The NSC at constant frequency operates optimally and its application for induction motor drive with re-active power compensation is proposed. In industries for various applications, induction motors are operated at constant frequency but at different loading conditions. These motors are operated at lagging power factor. The power distribution company demands high power factor operation and it gives benefits to consumer on operating a system closer to unity. In this paper, a control scheme is proposed to operate NSC drive at unity as well as at leading power factor with sinusoidal input current. The independent active–reactive power control technique is developed. The input–output active power relation is developed such that with the change in load, output active power matches input active power without affecting dc-link voltage. This results in faster dynamic response as compared to conventional dc-link balancing control techniques. With the proposed control scheme, the NSC is operated at desired leading power factor to compensate reactive power at point of common coupling. The simulation and experimental results show the feasibility of the proposed control scheme.

中文翻译：

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恒频运行的 NSC 驱动器的独立有功-无功功率控制方案

摘要 本文提出了一种新的控制方案，用于交流-直流-交流九开关转换器 (NSC)，感应电机以恒定频率运行。提出了恒定频率下的 NSC 优化运行，并提出了其在无功功率补偿感应电机驱动中的应用。在各种应用的工业中，感应电机以恒定频率但在不同负载条件下运行。这些电机以滞后的功率因数运行。配电公司要求高功率因数运行，它使消费者受益于运行更接近统一的系统。在本文中，提出了一种控制方案，以在单位以及正弦输入电流的超前功率因数下操作 NSC 驱动器。开发了独立的有功-无功功率控制技术。输入-输出有功功率关系是这样发展的，即随着负载的变化，输出有功功率与输入有功功率相匹配，而不影响直流母线电压。与传统的直流链路平衡控制技术相比，这导致了更快的动态响应。使用建议的控制方案，NSC 以所需的超前功率因数运行，以补偿公共耦合点的无功功率。仿真和实验结果表明了所提出的控制方案的可行性。NSC 以所需的超前功率因数运行，以补偿公共耦合点的无功功率。仿真和实验结果表明了所提出的控制方案的可行性。NSC 以所需的超前功率因数运行，以补偿公共耦合点的无功功率。仿真和实验结果表明了所提出的控制方案的可行性。