基于IEC 61850的数字化电能表用快速准同步谐波测量算法

Fast Quasi-Synchronous Harmonic Algorithm for IEC61850 Based Digital Energy Metering Devices

按IEC 61850-9-2 LE要求,数字化测量装置主要采用80′fr的固定采样率,在非同步采样下进行谐波分析,容易引起频谱泄漏。准同步算法具有较高的准确度,但计算复杂,硬件开销较大,不适合数字化电能表进行在线谐波分析和电能计量。该文针对数字化测量装置的特点,提出一种高效准同步谐波算法,具体采用等效加权窗函数与组合数快速傅里叶（fast Fourier transform,FFT）算法相结合的方式,使理论计算量减少了90%以上。通过仿真和试验,与Triangular窗插值离散傅里叶（Discrete Fourier transform,DFT）算法、Hanning窗插值DFT算法、Nuttall4（III）窗插值DFT算法进行比较,证明了该文提出的算法准确度更高,且硬件开销具有明显优势。

According to requirements of IEC 61850-9-2 LE, digital energy metering devices mainly adopt fixed 80′frsampling rate. When harmonic analysis is carried out with asynchronous sampling, it likely produces large errors due to spectral leakage. Quasi-synchronous algorithm has high accuracy, but its calculation process is complicated and its hardware expenditure is high. Based on the characteristics of digital energy metering devices, this paper puts forward an efficient quasi-synchronous harmonic algorithm using equivalent weighting window function combined with mixed radix fast Fourier transform algorithm. It reduces calculation amount by more than 90%. Compared with Triangle/Hanning/Nuttall4（III）-Windowed interpolated fast Fourier transform（FFT） algorithm, the proposed algorithm performs better in accuracy and hardware expenditure.