小波分析在电力系统谐波相位检测中的应用

为了防止电力系统谐波危害,保证系统安全运行,必须确切掌握电力系统中谐波的实际情况,正确分析电能质量.根据电网谐波中既存在稳态谐波分量又有暂态谐波分量的特点,依据小波分析具有对非平稳信号的分析和处理能力及多分辨率的特性,将小波变换理论应用于电网谐波检测中,提出了利用小波变换实现测量信号各次谐波相位的方法.仿真算例表明,小波多分辨分析法能够正确地提取电力系统的谐波信号,利用小波分解的尺度系数能得到各次谐波的精确相位,验证了该方法的可行性.

Application of wavelet analysis to phase measurement of power harmonic

In order to prevent the harmfulness of power harmonic to ensure the safety of power system,it is necessary to understand exactly the harmonic component in power system and analyse correctly the power quality.According to the characteristic of the power harmonic which includes steady and transient components and the wavelet analysis ability which processes unsteady signals and has the characteristic of multi-resolution analysis(MRA),the method of wavelet transform is applied to the detection of power harmonic.The theoretical basis for phase measurement of harmonic directly from the wavelet transform is proposed.It is proved that the harmonic signal can be exactly extracted by using the method of wavelet MRA and the phase value of harmonic component can be exactly obtained by using the approximate coefficient of wavelet decomposition by the simulation results.Simulation validates the feasibility of the proposed method.