基于解耦的双同步坐标系的三相锁相环设计

Design of three-phase PLL based on decoupled double reference frame

快速准确地跟踪电网电压是并网变换器稳定运行的保障。针对传统锁相环在电网电压畸变或不平衡下,不能实时并精确检测出基波正序分量幅值和相位的问题,提出了一种基于解耦的双同步坐标系(DDSRF)的三相锁相环设计方法,该方法通过引入解耦的双同步坐标系分离出基波正序分量,实现了基波正序分量的精确检测。仿真结果表明该三相锁相环能够在电网不平衡和畸变时快速准确地检测出电网电压基波正序分量的幅值和相位。

Accurate and fast tracking of utility voltage were essential to ensure correct operation of the grid-connected power converters. A method, three-phase phase-locked loop（PLL） based on decoupled double reference frame（DDSRF）, was put forward to deal with the problem that traditional PLL couldn＇t real-time and accurately detect the fundamental frequency positive-sequence component of the utility voltage under unbalanced and distorted conditions. By introducing the decoupled double reference frame, the fundamental positive-sequence component was isolated, then the precise detection of fundamental positive-sequence component was achieved. The simulation results show that the proposed design method of three-phase PLL can accurately and fast detect the amplitude and phase of the positive sequence component of utility voltage under unbalanced and distorted conditions.