改进型UPF谐波电流检测方法仿真研究

Study of Simulation of Harmonic Detection Algorithm with Improved Unit Power Factor

谐波电流对电网的影响日益严重,准确检测谐波电流是抑制谐波和补偿无功功率的一项关键技术。针对传统的谐波电流检测方法计算过程复杂和在电压畸变下无法获得准确的相位信息的情况下,对基于双二阶广义积分器的锁相环的基本原理进行分析与建模,代替传统锁相环。并结合单位功率因数谐波检测方法,提出了一种改进型谐波电流检测方法,实现了在电压畸变的情况下仍能快速准确地实现对补偿量的检测。运用Matlab软件分别对传统的UPF检测方法与基于双二阶广义积分器锁相环的UPF方法在电压畸变的情况下进行对比研究,结果表明传统的UPF检测方法在电压畸变的环境下电流畸变率为13.81%,改进后的UPF检测方法的电流畸变率为3.12%,后者与前者比较,其受电压畸变影响较小,可以准确检测出负载电流的谐波及无功分量。

As the influence of harmonic current on power grids increases,accurate detection of harmonic current is a key technology to suppress harmonics and compensate reactive power.In case that the complicated calculation process of traditional harmonic current detection method and accurate phase information cannot be obtained under voltage distortion,the traditional phase-locked loop has been replaced by the double second order generalized integrator SPLL(DSOGI-SPLL),which is analyzed and modeled by the basic principle of phase-locked loop.Combining with the unit power factor harmonic detection method,an improved harmonic current detection algorithm is presented,which can realize the detection of the compensation amount quickly and accurately under the condition of voltage distortion.The Matlab software is used to compare the traditional UPF detection method with the improved algorithm in the case of voltage distortion.In the end,the results show that the traditional UPF detection method has a current distortion rate of 13.81%in the environment of voltage distortion,and current distortion rate of the improved algorithm is 3.12%.Comparing with the former,the latter is less affected by voltage distortion,and can accurately detect the harmonic and reactive components of the load current.