【摘要】 构造了新型的用于高压输电线路保护的故障选相元件。利用小波分析良好的时频局部化特性,在暂态信号多尺度表示方法的基础上定义了用于特征提取的小波能量熵,并与模糊逻辑相结合形成新的选相原理。先对采集到的故障后电压信号进行适当的小波分解,并计算小波能量熵,然后构造包含故障信息的模糊语言变量作为模糊推理系统的输入,并建立相应的模糊逻辑推理系统,通过模糊逻辑的方法进行故障选相。仿真结果表明,小波能量熵随时间变化的规律能有效反映故障出现与否,并通过模糊逻辑做出选相判断。更多还原

【Abstract】 A new faulty phase selector for high voltage power transmission system is presented.Utilizing the time-frequency localization ability of wavelet analysis,on the basis of multi-scale expression of transient signals,the concept of wavelet energy entropy(WEE)for feature extraction is defined;integrating WEE with fuzzy logic,a new method to select faulty phase is formed.First,appropriate wavelet decomposition of acquired post-fault voltage signal is conducted and the WEE is calculated;then as the input of fuzzy reasoning system the fuzzy linguistic variables containing fault information are constructed and corresponding fuzzy reasoning system is built;finally,the faulty phase is selected by means of fuzzy logic method.Simulation results of PSCAD/EMTDC and Matlab show that the variation regularity of WEE with time can effectively reflect whether fault occurs or not,and the faulty phase can be judged by fuzzy logic.更多还原