Abstract This work presents a phase-locked loop (PLL) algorithm for the detection of positive-sequence and negative-sequence grid voltages in three-phase systems. Since it employs an adaptive filter (AF), it is possible to track the fundamental component of the grid voltages accurately even in the presence of harmonics, subharmonics, and interharmonics. This aspect is of major concern for practical applications, especially because some popular algorithms present limited performance in such scenarios, e.g., the decoupled double synchronous reference frame PLL (DDSRF-PLL) and double second-order generalized integrator frequency-locked loop (DSOGI-FLL). A thorough comparison among the proposed method and other similar structures is presented in terms of steady-state and dynamic behaviors to show that the introduced PLL presents high immunity to power quality disturbances. Unfortunately, a possible drawback lies in the slow dynamic response due to the AF. In order to verify the applicability of the proposed approach, it is also incorporated to the control structure of a grid-connected power converter operating as a static synchronous compensator (STATCOM). This converter aims at regulating the ac voltage at the point of common coupling (PCC) and power factor correction. A detailed mathematical analysis is presented and experimental results are also discussed to validate the theoretical assumptions.

中文翻译：

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三相锁相环算法及其在静态同步补偿器中的应用

摘要 这项工作提出了一种锁相环 (PLL) 算法，用于检测三相系统中的正序和负序电网电压。由于采用了自适应滤波器 (AF)，因此即使存在谐波、次谐波和间谐波，也可以准确跟踪电网电压的基波分量。这方面是实际应用的主要关注点，特别是因为一些流行的算法在这种情况下表现出有限的性能，例如去耦双同步参考框架 PLL (DDSRF-PLL) 和双二阶广义积分器锁频环 (DSOGI- FLL）。所提出的方法与其他类似结构在稳态和动态行为方面进行了彻底的比较，以表明引入的 PLL 对电能质量干扰具有很高的免疫力。不幸的是，一个可能的缺点在于由于 AF 导致的动态响应缓慢。为了验证所提出方法的适用性，它还被纳入作为静态同步补偿器 (STATCOM) 运行的并网功率转换器的控制结构中。该转换器旨在调节公共耦合点 (PCC) 和功率因数校正点的交流电压。提出了详细的数学分析，并讨论了实验结果以验证理论假设。一个可能的缺点是由于 AF 导致动态响应缓慢。为了验证所提出方法的适用性，它还被纳入作为静态同步补偿器 (STATCOM) 运行的并网功率转换器的控制结构中。该转换器旨在调节公共耦合点 (PCC) 和功率因数校正点的交流电压。提出了详细的数学分析，并讨论了实验结果以验证理论假设。一个可能的缺点是由于 AF 导致动态响应缓慢。为了验证所提出方法的适用性，它还被纳入作为静态同步补偿器 (STATCOM) 运行的并网功率转换器的控制结构中。该转换器旨在调节公共耦合点 (PCC) 和功率因数校正点的交流电压。提出了详细的数学分析，并讨论了实验结果以验证理论假设。