基于改进FFT的合并单元检测方法研究

Research on Testing Method of Merging Unit Based on Improved FFT

采用传统快速傅里叶变换作为合并单元计量性能检测装置的信号分析算法时,由于存在频谱泄漏问题,比差和角差易超出0.05级检测装置的精度要求。对此,提出了基于加Nuttall窗的插值快速傅里叶变换法,在PSPICE平台上对改进算法和传统算法进行含谐波信号的仿真分析和比较,结果表明,改进算法的信号分析精度较高,更适合用于合并单元计量性能校验。最后搭建实测平台进行了校准试验,测试数据表明检测装置的误差能满足0.05级精度要求,验证了本文方法的可行性。

When the conventional FFT algorithm is used as the algorithm of the combined unit metrology perform- ance calibrator, because of the spectrum leakage and fence effect, the ratio difference and the difference do not meet the 0. 05 level accuracy requirement. In this regard, based on the conventional FFT, put forward FFT interpo- lation algorithm with Nuttall window, comparison, simulation on PSPICE platform for Harmonic Improvement Algo- rithm and conventional F^F algorithm. The results show that the calculation of this algorithm is of high accuracy and is more suitable for measuring performance verification of merging unit. Finally, the calibration test of the combined unit metering performance calibrator is carried out at the Wuhan high voltage station. The test data show that the calibrator meets the requirement of 0.05 level accuracy, which verifies the feasibility of the method.