一种混合递推的DFT相量测量算法  

A mixed recurrence DFT algorithm for phasor measurements

作　　者：杨力森[1] 汪芳宗[1] 孙水发[1] 

机构地区：[1]三峡大学电气信息学院,湖北宜昌443002

出　　处：《继电器》2008年第5期23-27,共5页Relay

摘　　要：电力系统的稳定、安全、经济的运行需要快速准确地采集实时的电压和电流的有效值(幅值)与相位。然而,电网的频率是波动的,使采样很难做到对被测信号进行整周期截断,FFT算法的栅栏效应和泄漏现象,将导致明显的测量误差。提出一种混合递推的DFT相量测量算法。首先,利用频谱修正法获得精确的电网频率,然后采用相量校正算法纠正误差。通过滑动数据窗的递推算法提高了计算效率和时间响应,仿真证实了所提算法是有效和可行的。Accurate and quick acquisition of effective values（or amplitudes） and phases of real time current and voltage is needed to guarantee the stability, security and economics of power systems, However, the frequency of the grid is always fluctuating, which makes the sampling signals non-synchronous. And the railing effect and leakage of FFT algorithm will result in obvious measurement errors. This paper introduces a mixed recursive DFT algorithm for phasor measurements. First, the spectrum correction theory is applied to obtain the precision frequency of the grid. Furthermore, an improved phasor computing algorithm is proposed to correct the error. This algorithm based on a sliding window can enhance the computational efficiency and time response greatly. The simulation results verify the effectiveness and practicability of the algorithm.

关 键 词：相量测量 递推DFT 频谱修正 滑动窗口 

分 类 号：TM933.3[电气工程—电力电子与电力传动]