基于全复数型滤波器的三相锁相环技术  

A Three-Phase Phase-Locked Loop Technique Based on All Complex Coefficient Filter

作　　者：何宇[1,2] 漆汉宏[2] 邓小龙[1] He Yu;Qi Hanhong;Deng Xiaolong(School of Intelligent Engineering Jiangsu Vocational College of Information Technology,Wuxi 214153,China;School of Electrical Engineering Yanshan University,Qinhuangdao 066004,China)

机构地区：[1]江苏信息职业技术学院智能工程学院,无锡214153 [2]燕山大学电气工程学院,秦皇岛066004

出　　处：《电工技术学报》2021年第10期2115-2126,共12页Transactions of China Electrotechnical Society

基　　金：江苏省高等学校自然科学研究项目(19KJB460028,20KJB520021);江苏省高等学校优秀科技创新团队项目(2019SJK07);江苏信息职业技术学院2020年重点科研课题项目(JSITKY202008)资助。

摘　　要：近年来,前置复数滤波器(CCF)的锁相环(PLL)技术成为电网同步研究中的热点。然而,现有的CCF-PLL已被证实其数学模型和控制性能与传统的实数滤波器型PLL基本一致。为提高系统的控制性能,该文提出一种CCF结构完全复数化的三相PLL技术。首先,给出前级滤波结构关于电压的传递函数,验证该结构可以准确分离出电网的基波正负序分量。其次,进行前级结构关于基波正序相位的数学建模,结合后级的同步旋转坐标系PLL,构建整个PLL系统关于相位的数学模型,并利用三阶最佳校正法对系统进行设计,确定相关控制参数。研究发现,若采用与CCF-PLL相同的开环截止频率,所提PLL的中频段宽度更宽、相位裕度更大。另外,还设计了多重全复数滤波结构级联的三相PLL,以便更彻底地抑制电网谐波。最后,通过仿真和实验进行验证,结果表明,相比CCF-PLL,所提PLL的控制性能更佳。Recently,the complex-coefficient-filter(CCF)-based phase-locked loop(PLL)technique has become a hotspot in grid synchronization research.However,the mathematical model and control performance of the current CCF-PLL have been confirmed to be basically consistent with the traditional real coefficient filter PLL.In order to improve the control performance,a novel three-phase PLL based on all complex coefficient filter is put forward.Firstly,the voltage transfer function of the pre-stage filter structure is given,and it is demonstrated that the structure can accurately separate the fundamental positive-and negative-sequence components.Then,the mathematical model of the pre-stage structure on the fundamental positive-sequence phase is derived.Combined with the post-stage synchronous rotating frame PLL,the mathematical model of the entire PLL system is built,and then the system is designed by the third-order optimum correction method.Wherein,the related control parameters are determined.It is shown that with the same open-loop cut-off frequency,the proposed PLL has a wider mid-frequency band width and a larger phase margin than the CCF-PLL.In addition,a multiple all-complex-coefficient-filter based PLL is designed to thoroughly eliminate harmonics.Finally,simulation and experimental results show that the control performance of the proposed PLL is better than that of the CCF-PLL.

关 键 词：锁相环 复数滤波器 控制性能 相位裕度 

分 类 号：TM464[电气工程—电器]