基于同步旋转坐标下多倍频DFT算法和重复控制的APF快速控制策略

Fast Control Strategy of APF Based on Multiple Frequency DFT Algorithm and Repetitive Control in Synchronous Rotation Coordinates

传统DFT谐波检测算法和重复控制均存在一定的固有延时,严重影响有源电力滤波器的动态响应性能。为了改善系统动态响应能力,本文首先结合负载谐波电流经同步旋转变换后的特征,提出同步旋转坐标下6倍基础计算频率的DFT加速算法,缩短谐波提取固有延时的同时,减少计算量及数据占用空间。其次,建立倍频化重复控制结构,给出n倍控制频率重复控制准内模衰减函数的设计方法和表达形式。并对基于同步旋转坐标的6倍频重复控制展开详细的控制参数设计。最后,搭建实验样机验证了所提方法的有效性。

Traditional DFT harmonic detection algorithm and repetitive control both have certain inherent delay,which affects seriously the dynamic response performance of active power filters.In order to improve the dynamic response capability of the system,in this paper,the he accelerating DFT algorithm in synchronous rotation coordinates with six-fold basic calculating frequency is proposed with combination of the feature of load harmonic current through synchronous rotation transformation so to,at the same time of shortening the inherent delay of harmonic extraction,reduce the computation amount and data space occupied by the algorithm.Secondly,the control structure of multiple frequency repetitive control is set up and the design method and expression form of quasi-internal model attenuation function of n-fold control frequency based repetitive control are given.Then detailed control parameters design is carried out for six-fold frequency repetitive control based on synchronous rotation coordinates.Finally,the effectiveness of proposed method is verified by the experimental prototype.