Abstract Recently, various phase locked loop (PLL) methods have been improved for a reliable and robust synchronization under non-ideal grid conditions. One of the PLLs is a hybrid PLL (HPLL) which is an improved structure of the quasi-type-1 PLL (QT1-PLL) method. In this paper, an enhanced HPLL that offers both fast transient response and increased disturbance rejection capability for dominant harmonics is proposed. The proposed PLL includes adaptive all-pass-filters (APFs) in pre-filtering stage to eliminate fundamental frequency negative sequence (FFNS) component. Thus, window-width of the moving average filter (MAF) is reduced by three times compared with the HPLL by means of removing the FFNS component. So, the proposed PLL, which is called fast-hybrid PLL (FH-PLL), considerably ensures a fast transient response. Also, in case of grid faults (for example, type-B, type-C, type-D, and etc.), at the same time frequency change occurs, the FH-PLL completely blocks the FFNS component by means of using adaptive DAPF. In this study, it is experimentally implemented HPLL, QT1-PLL, and the proposed FH-PLL methods. The effectiveness of the FH-PLL is verified owing to experimental results and comparison with the QT1-PLL and HPLL.

中文翻译：

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异常电网条件下具有自适应全通滤波器的快速混合锁相环

摘要 最近，为了在非理想电网条件下实现可靠​​和稳健的同步，各种锁相环 (PLL) 方法已经得到改进。PLL 之一是混合 PLL (HPLL)，它是准 1 型 PLL (QT1-PLL) 方法的改进结构。在本文中，提出了一种增强型 HPLL，它既提供快速瞬态响应，又提高了对主要谐波的干扰抑制能力。建议的 PLL 在预滤波阶段包括自适应全通滤波器 (APF)，以消除基频负序 (FFNS) 分量。因此，通过去除 FFNS 分量，移动平均滤波器 (MAF) 的窗口宽度与 HPLL 相比减少了三倍。因此，建议的 PLL，称为快速混合 PLL (FH-PLL)，可显着确保快速瞬态响应。还，在电网故障（例如B型、C型、D型等）的情况下，在发生频率变化的同时，FH-PLL通过使用自适应DAPF完全阻断FFNS分量。在这项研究中，它通过实验实现了 HPLL、QT1-PLL 和建议的 FH-PLL 方法。由于实验结果和与 QT1-PLL 和 HPLL 的比较，验证了 FH-PLL 的有效性。