基于品质因子可调小波变换与排列熵的电能质量信号检测方法

Power quality signal detection method with tunable Q-factor wavelet transform and permutation entropy

为有效检测电能质量信号,提出一种基于品质因子可调小波变换(TQWT)与排列熵的检测方法。方法利用电能质量信号与噪声信号品质因子的不同,通过品质因子小波变换将信号分解为高共振分量(电能质量信号)、低共振分量(脉冲噪声)及余项(随机噪声),从而实现电能质量信号与脉冲噪声和随机噪声的分离。通过排列熵值的变化检测出信号的突变点,捕捉扰动信号的起止时刻。该方法可有效抑制脉冲噪声与随机噪声,且波形畸变小、扰动特征提取准确。仿真结果验证了所提方法的可行性与有效性。

To effectively detect the power quality signal,a method with the tunable Q-factor wavelet transform(TQWT)and permutation entropy was proposed in this paper.Using the distinct Q-factor of power quality signal and noise signal,power quality signals were decomposed into high resonance component(power quality signal),low resonance component(impulse noise)and residual(random noise)by TQWT,which realized the separation of power quality signal,impulse noise and random noise.By changing of the permutation entropy to detect the mutation point of the signal,the starting and ending time of the disturbance signal were captured.The method could effectively suppress the impulse noise and random noise,the waveform distortion was small,and the disturbance feature was accurately extracted.Simulation results proved the feasibility and effectiveness of the proposed method.