电力信号相位差测量方法之探讨

A discussion about the measurement methods of power signals phase difference

在电力系统中常常需要对两个同频率信号(如工频电压和工频电流)之间的相位关系进行准确的测量。本文对“相位—时间”法和“功率比例法”这两种传统的相位差测量方法进行了较为详细的分析,对基于离散付里叶变换的相位测量原理进行了详细的讨论,并给出了实测数据。分析表明,基于离散付里叶变换原理的相位测量方法具有测量精度高、抗干扰能力强、电路设计简单等特点。

The phase difference often needs to be measured between two signals with the same frequency in power system,such as power voltage and power current signals.The limitation of two traditional methods to measure the phase difference,i.e., the 'phase-time' method and the 'power proportion' method are discussed in detail in this paper;the principle based on discrete fourier transform (DFT)is also discussed thoroughly,and actual field datas are given here. It is pointed out that the method based on DFT can measure the phase difference with high accuracy.The analysis shows,compared with the traditional methods,the DFT method is characterized with high measuring accuracy,favorable anti-disturbance ability and simple circuitry.