中文摘要：

基于传统快速傅里叶变换（FFT）频谱分析,提出测量功率因数角获取功率因数的方法,分析该方法的实现原理,完成一套以定点数字信号处理器（DSP）为核心的测量装置.在同步采样和非同步采样方式下,进行正弦信号与方波信号的测量实验.实验结果表明,采用该方法,正弦信号在同步采样和非同步采样情况下都能够获得准确的相角差;而方波信号即使在非同步采样情况下通过提取基波信号也能够获得准确的相角差.

英文摘要：

The traction motor of linear metro is the large air gap linear induction motor and its power factor floats with the operating conditions simultaneously.Based on the traditional fast Fourier transform（FFT） spectrum analysis,a method of obtaining power factor by measuring power factor angle was proposed.After the analysis of this method＇s implementation principle,a set of measuring device was established,using a fixed-point digital signal processor（DSP） as the core.Experiments of sine signals and square wave signals were took respectively,in synchronous sampling and non-synchronous sampling cases.The experimental results show that the accurate phase angle difference of sine signals could be obtained by using the proposed method in synchronous sampling and non-synchronous sampling cases while for square wave signals,the accurate phase angle difference could also be obtained through extracting the fundamental signals,even in the case of non-synchronous sampling case.