Morlet复小波算法在自适应电流保护中的应用研究  

Study on application of Morlet complex wavelet on adaptive current protection

作　　者：揭林玲[1] 唐昆明[1] 张太勤 

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030 [2]重庆新世纪电气有限公司,重庆400030

出　　处：《电力系统保护与控制》2009年第22期40-43,48,共5页Power System Protection and Control

摘　　要：自适应电流保护算法中关键之一是实时而准确地计算系统等值参数。一般傅氏算法在计算系统等值阻抗时受短路电流非周期分量和电网频率不稳定的影响,会产生较大的误差。而Morlet复小波算法具有频率特性好,不受非整次谐波、非周期分量及电网频率波动的影响,因此本文提出了采用全周Morlet复小波算法计算系统等值参数的方法,通过选择合理的Morlet复小波函数参数,提取配电网典型故障电流电压的工频分量来计算系统等值参数。经仿真分析表明用该方法实时计算等值参数,精度高,能满足保护性能要求,具有很高的工程实用价值。Real-time calculating system equivalent parameters is one of keys of adaptive current protection. Full-wave Fourier algorithm will cause high error because of the non-periodic component and unstable power frequency. A Morlet complex wavelet based algorithm is presented which is better than general Fourier algorithm in stability and robustness and is unaffected by non-integer harmonics, non-periodic component and fluctuant frequency. The algorithm is to choose proper parameters and filter out fundamental frequency components of typical faults voltages and currents. The results of simulation show that the complex wavelet algorithm is of high accuracy and can satisfy adaptive protection＇s need, so it is highly valuable for engineering practice.

关 键 词：配电网 电流保护 自适应保护 傅氏算法 Morlet复小波 

分 类 号：TM771[电气工程—电力系统及自动化]