一种实时精确估计电力谐波和间谐波参数的方法

A Real-time Accurate Estimating Method for Electric Power Harmonics and Inter-harmonics

提出一种电力谐波和间谐波参数实时高精度估计的新方法。首先利用对称窗函数的能量谱重心导出各电力谐波的频率和相位的估计算法;接着使用Parseval定理推导出精确估计电力谐波幅值的计算公式;进而分析了估计误差,估计误差仅与加权窗函数的能量分布特性有关,某次谐波的估计相对误差不大于窗函数在频域中旁瓣所占能量与总能量的比值。最后,仿真试验表明,所提方法与其他加窗快速傅里叶变换插值校正分析方法在计算耗时上有明显优势。模拟试验证明,所提方法很适合用于嵌入式系统和数字信号处理器,是一种很实用的算法。

A new real-time accurate estimating method for electric power harmonic and inter-harmonic parameters is proposed. First,the estimating algorithm of frequency and phase estimation for a harmonic or inter-harmonic is deduced using the discrete spectrum power center of symmetric windows,and then the amplitude calculation of electric power harmonic is inferred by using Parseval theorem.The estimation error is analyzed.The estimation error of an electric harmonic is only related to the energy distribution of the weighted window function in the frequency domain.The relative error of an electric harmonic is no greater than the proportion of the spectrum energy of the window function in the side lobe to the total.Finally,the simulation tests show that the method proposed has apparent advantages in computing time consumption over other windowed Fourier transform interpolation corrective analysis methods.The results of physical simulation tests show that the method proposed is very suitable for embedded systems and digital signal processors.