基于离散傅立叶变换校正的电参量微机测量新算法及应用研究

IMPROVED SPECTRUM CORRECTION ALGORITHM OF ESTIMATING POWER ELECTRIC PARAMETERS AND ITS APPLICATIONS

离散傅立叶变换(DFT)是电参量微机测量的常用算法,但非同步采样引起的频谱泄漏及栅栏效应,使估计出的信号频率、幅值及相位有较大的误差。该文根据电气信号的频谱特点,对DFT频谱校正实现方法进行改进,提出了适合电参量微机测量的新算法,并通过选用不同的采样时间窗长度、采样点数及与之相适应的窗函数,使新算法可以满足高精度计量及快速电气测量等多种应用场合对测量精度、实时性等性能的不同要求。算法实现简单,速度快、精度高、通用性强,仿真分析和科研实践验证了其可行性和有效性。

DFT is one of the most common measuring algorithms of estimating power electric parameters. However, because of leakage and picket-fence effect caused by asynchronous sampling, the error occurs as the traditional estimating algorithm is applied. According to the characteristics of power electric signals, a novel algorithm, which is based on the improved DFT spectrum correction technology and needs no synchronous sampling, is present. By choosing different length of data window, sampling frequency, and corresponding windows, the algorithm can meet the different demands of computing speed and precision at various applying situation, such as measurement, control, and protection in power system. The algorithm can be easily employed; both the simulation results and the practices show its feasibility and effectivity.