孤网失稳状态下频率和暂态谐波分析方法  

An Analysis Method for Frequency and Transient Harmonics of Isolated Network Under Instable Condition

作　　者：阳登辉 朱明星[1] 徐斌 YANG Denghui;ZHU Mingxing;XU Bin(School of Electrical Engineering and Automation,Anhui University,Hefei 230601,China;Electric Power Research Institute of State Grid Anhui Electric Power Co.,Ltd.,Hefei 230601,China)

机构地区：[1]安徽大学电气工程与自动化学院,安徽合肥230601 [2]国网安徽省电力有限公司电力科学研究院,安徽合肥230601

出　　处：《中国电力》2021年第8期27-34,共8页Electric Power

基　　金：国网安徽省电力有限公司科技项目(521205190025)。

摘　　要：针对孤网失稳状态下频率和谐波快速宽频变化导致的傅立叶谐波分析频谱泄漏问题,提出了一种基于自适应变带宽周期滑动滤波的频率和暂态谐波分析方法。首先通过基于周期滑动滤波原理的预处理系统消除非平稳信号的高频周期干扰,并剔除直流分量;然后对预处理后的序列采用零交法进行实时锁相,自适应调整周期滑动滤波器的带宽;最后根据计算的非平稳信号实时频率,利用DFT算法对非平稳信号进行谐波分析,准确得到每一个谐波成分的暂态信息。仿真结果及现场实测数据表明,该方法在多种非平稳状态下均具有较高的谐波测量精度,能够有效地对孤网失稳状态下频率和暂态谐波进行测量。Focusing on the problem of spectrum leakage in Fourier harmonic analysis caused by rapid broadband changes in frequency and harmonics in isolated network under unstable condition,an analysis method for frequency and transient harmonics is proposed based on adaptive periodic sliding filter with variable bandwidth.Firstly,the high-frequency periodic interference of nonstationary signal is eliminated by the preprocessing system based on the principle of periodic sliding filter,and the DC component is separated.Then the preprocessed sequence is locked in real time by zero crossing method,and the bandwidth of the periodic sliding filter is adjusted adaptively.Finally,according to the real-time frequency of the calculated non-stationary signal,the non-stationary signal is divided into harmonics by the discrete Fourier transform(DFT)algorithm,and the transient information of each harmonic component is obtained accurately.Simulation results and field measurement data show that the method has high harmonic measurement accuracy under a variety of non-stationary states,and can effectively measure the frequency and transient harmonics of isolated network under the unstable state.

关 键 词：孤网失稳 暂态谐波 自适应变带宽 周期滑动滤波 零交法 实时锁相 

分 类 号：TM935[电气工程—电力电子与电力传动]