Repetitive controller provides a very low third harmonic dimension in the quantities under control. It exhibits an inherent issue when operated to track variable frequency references. The article deals with the analysis of the operating conditions when the controller is executed at variable frequency without any resynchronization with respect to the pulsewidth modulation carrier, which is the most common mode of operation. The delays introduced are then evaluated analytically concerning the sampling and output frequency that must be tracked. The proposed analysis allows obtaining the maximum delay affecting the control chain, which was introduced by the repetitive control desynched operation. The knowledge of the delay introduced in the control loops is at the basis of any control tuning procedure and gains selection, even when adaptive control strategies are used.

中文翻译：

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交流变频应用中基于 FPGA 的重复控制器的分析延迟评估

重复控制器在控制量中提供非常低的三次谐波维度。当用于跟踪可变频率参考时，它表现出固有的问题。本文分析了当控制器以可变频率执行而无需与脉宽调制载波（这是最常见的操作模式）进行任何重新同步时的操作条件。然后对引入的延迟进行分析评估，涉及必须跟踪的采样和输出频率。所提出的分析允许获得影响控制链的最大延迟，这是由重复控制失同步操作引入的。即使在使用自适应控制策略时，控制环路中引入的延迟的知识也是任何控制调谐过程和增益选择的基础。