一种新的基于小波变换和混沌理论的触电信号检测方法

A novel detecting method of electric shock signal based on wavelet transform and chaotic theory

提出一种集小波多分辨分析和李雅普诺夫指数于一体的触电电流混沌检测新方法。该方法对触电前后的总泄漏电流进行消噪和滤波,根据混沌系统从混沌状态到大尺度周期状态的分岔行为具有对小信号敏感性和对噪声免疫性的特性,将最大李雅普诺夫指数作为判断混沌系统相变的量化依据,自动判别触电前后混沌系统的临界状态,从而计算出其中包含的触电电流分量。仿真结果表明,该方法能够从包含强噪信号的总泄漏电流中检测出微弱的触电电流信号,对于开发新一代剩余电流保护装置具有一定的参考价值。

A novel chaotic detection of the electric shock current integrating wavelet multi-resolution method and Lyapunov exponent is introduced.First of all,the summation leakage current before and after electric shock is de-noised and filtered.And then,electric shock current component is extracted according to the characteristic that chaotic system’s bifurcation action from chaotic state to scale periodic state is sensitive and immune to weak signals and noises respectively.The largest Lyapunov exponent is proposed as the judgment criterion of phase transition of chaotic system.It can automatically recognize the critical state before and after electric shock.Simulation results show that this method can detect weak electric shock current in the summation leakage current containing strong noise.The detecting method is of a certain reference value for developing new generation residual current operation devices.