基于复化梯形的准同步采样频率测量算法

Quasi-synchronous Sampling Algorithm for Frequency Measurement Based on Multiple Segment Trapezoidal Rule

电力系统频率波动使严格的同步采样难以实现。由于不可避免的存在非同步采样偏差,电力系统频率及其它参数测量准确度受到限制。为此,该文研究基于数值积分的准同步采样算法,推导基于复化梯形的准同步采样频率测量算法,建立电力系统频率测量实现流程。并且仿真分析基于复化梯形的准同步采样算法、基于4项3阶Nuttall窗和Hanning窗插值快速傅里叶变换(fast Fourier transform,FFT)算法的频率测量精度和抗噪性。仿真结果表明,与插值FFT算法相比,所提基于复化梯形的准同步采样算法能有效地提高频率测量的准确度,且能有效抑制白噪声的影响。利用标准功率源的频率测量实验验证了所提算法的有效性和准确性。

Fluctuations of power system frequency make it difficult to implement the synchronous sampling strictly. In the case of asynchronous sampling, deviation of frequency measurement is inevitable, which limits the accuracy of measurement of the power system frequency and the other parameters. Therefore, this paper studied the quasi-synchronous sampling algorithm based on numerical integration, deduced the quasi-synchronous sampling algorithm based on multiple segment Trapezoidal rule and established the calculation flow of power system frequency measurement. Some simulations were conducted to analyze the accuracy of frequency measurement and the ability of anti-noise of the quasi-synchronous sampling algorithm based on multiple segment Trapezoidal rule, the interpolation fast Fourier transform （FFT） algorithm based on four-item and third-order of Nuttall window and Hanning window. Simulation results show that, compared with the interpolation FFT algorithm, the proposed method in this paper can not only improve accuracy of frequency measurement effectively, but also inhibit the influence of white noises effectively.Frequency measurement experiment has confirmed the effectiveness and accuracy of the proposed method in this paperby using standard power source.