基于最小二乘法和时频原子变换的谐波/间谐波测量算法  

Monitoring of Power System Harmonic/Inter-Harmonics Based on Least Squares Algorithm and Time Frequency Transform

作　　者：曹健[1] 林涛[1] 徐遐龄[1] 张蔓 刘林[1] 

机构地区：[1]武汉大学电气工程学院,武汉430072 [2]南方电网超高压输电公司,广州510405

出　　处：《电工技术学报》2011年第10期1-7,共7页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(50677044)

摘　　要：提出了最小二乘法与时频原子变换相结合的谐波/间谐波测量方法。应用最小二乘法对整个测量频段扫频,获取谐波/间谐波分量的个数和大致频率。依次对各个分量跟踪配置时频原子变换对应的带通滤波器,精确测量其频率和幅值。时频原子变换是具有自适应复带通滤波特性的新型时频分析方法,其频窗宽度与频窗中心相互解耦,可以灵活调整而不受窗函数中心频率的限制。通过构造频窗互不交叉的复带通滤波器来抑制频率邻近分量之间的干扰,同时能在非同步采样条件下抑制基波频率波动对测量精度的影响。仿真结果表明该方法具有测量精度高、计算量小、抗噪性能好等优点。A new harmonic/inter-harmonic detecting method is presented in this paper,which is based on least-square method and time-frequency transform（TFT）.In the first step of approach,least-square algorithm is used to obtain the number and approximate frequency of harmonic and inter-harmonics by scanning the whole frequency band.Then,TFT is applied to detect harmonics interharmonics＇ accurate frequency and amplitude of each component through configuration of complex band pass filter（CBPF） corresponding to TFT.TFT is a novel time frequency analysis method with the characteristic of adaptive complex band pass filter.It decouples the center and the width of frequency window,so the the width of frequency can be adjusted freely without the restriction from the center frequency window.Mutually uncrossed CBPF is constructed to inhibit interference of adjacent frequency component.Also,it can inhibit the influence of fundamental frequency＇s fluctuation on measuring accuracy under asynchronous sampling.The simulation results indicate that this method has the advantage of high detecting accuracy,low calculation amount and great anti-noise performance.

关 键 词：电力系统谐波 间谐波 最小二乘法 时频原子变换 复带通滤波器 

分 类 号：TM714[电气工程—电力系统及自动化]