基于线性滤波器的三相四线制谐波电流检测

摘要

Aiming at the structure of three-phase four-wire system and the limitation of some existing detecting methods for harmonic currents, a novel harmonic currents detection algorithm for unbalanced three-phase four-wire system is proposed based on the 2-D linear filter and instantaneous symmetrical components.The detection principle lies in that asymmetrical fundamental components are extracted by 2-D linear filters, then fundamental positive sequence components can be obtained with improved instantaneous symmetrical components, lastly, harmonic components can be extracted.The model of three-phase four-wire APF has been built in Simulink to verify the feasibility and validity of the proposed method.The results of simulation show that the proposed method has an accurate and fast response to the extraction of harmonic currents and reactive currents, and it has a good static performance and dynamic performance.%针对三相四线制电力系统的结构特点及现有谐波检测方法的不足,提出了一种基于二维线性滤波器和瞬时对称分量计算的不对称三相四线制谐波电流检测新算法.该算法的检测原理是利用二维线性滤波器分别检测出各相不对称基波电流,通过改进瞬时对称分量法得到各相电流基波正序分量,从而检测出各相谐波电流.理论推导和Simulink仿真结果表明,该方法能够准确快速地检测出三相四线制电力系统中的谐波电流及无功电流,具有较好的动静态性能.