【摘要】 针对电力系统中非线性负荷所产生的谐波电流特点,提出应用小波变换处理电能质量扰动信号,突出畸变信号以进行谐波阻抗估计,克服了傅里叶变换无法进行时-频局部化分析的缺陷,提取出局部时间范围内所需频带信号。介绍了其基本原理,以及小波分析窗口的选择和波动量的计算。应用Matlab建立电路模型进行仿真,结果表明该方法提高了系统谐波阻抗估计值的幅值精度。更多还原

【Abstract】 According to the characteristics of harmonic current caused by nonlinear load of power system,an approach to harmonic impedance assessment is proposed,which applies wavelet transform to process the disturbance signal of power quality and emphasizes the distorted signals. It over-comes the limitation of Fourier transform in time-frequency localizing analysis and obtains the signals of required frequency band. Its principle is introduced,and the wavelet window selection and distortion quantity calculation are detailed. The circuit model is established with Matlab. Results show that the proposed method helps to improve the amplitude accuracy of system harmonic impedance assessment.更多还原