不平衡及谐波电网下基于多模块复数滤波器的电网阻抗检测方法

摘要

For the purpose of acquiring the accurate value of grid impedance rapidly under unbalanced grid voltage and background harmonics,a grid impedance detection method is proposed based on multiple complex coefficient filters (MCCF)and uncharacteristic harmonic injection. MCCF is applied to accurately extract the uncharacteristic harmonic components of the voltage and current at the point of common coupling, and further calculate the resistive and induc-tance components of grid impedance. The basic principle and design method for extracting uncharacteristic harmonics through MCCF are studied, and the optimization design of MCCF parameters is performed from aspects of extraction ac-curacy and dynamic performance. Finally, simulation results verify the feasibility and effectiveness of the proposed grid impedance detection method.%为保证电网不平衡及电网背景谐波情况下快速获取准确的电网阻抗信息,提出了一种基于多模块复数滤波器MCCF(multiple complex coefficient filters)和非特征次谐波注入的电网阻抗检测方法.所提电网阻抗检测方法使用MCCF实现对公共耦合点电压非特征次谐波分量和电流非特征次谐波分量的准确提取,从而计算得出电网阻抗的阻性分量和感性分量.研究了在电网不平衡及电网背景谐波情况下MCCF 提取非特征次谐波的基本原理及设计方法,并从提取精度和动态性能等方面对MCCF的参数进行了优化设计,最后仿真验证了所提电网阻抗检测方法的可行性和有效性.