Method for measuring instantaneous phase of alternating current electrical signal

Abstract

The invention provides a method for measuring instantaneous phase of an alternating current (AC) electrical signal, which is also suitable for measuring the instantaneous phase of a low frequency signal. The method comprises the following steps of: firstly, preprocessing sampling values of the AC electrical signal; then, looking up table and calculating zero crossing point time of the AC electrical signal when the AC electric signal changes from low to high for previous cycles of the alternating current electrical signal; secondly, calculating the period of the alternating current electrical signal through the zero crossing point; thirdly, predicting the periods of the previous cycles; and finally, calculating the instantaneous phase of the alternating current electrical signal through the zero crossing point time, the predicted alternating current electrical signal period and the current time. Compared with a traditional zero crossing method, the alternating current electrical signaldoes not need to be converted into square wave, so the method overcomes the defect of poor anti-interference capability of the traditional zero crossing point detection, is particularly suitable for the measurement of the instantaneous phase of the alternating current electrical signal and has convenient system detection and low hardware cost; and meanwhile, the method has the advantages of simple and rational implementation, accurate and reliable data, great improvement on the measuring accuracy and anti-interference capability and the like.

Description

technical field [0001] The invention relates to an instantaneous phase measurement method of alternating current signals, which is also suitable for the instantaneous phase measurement of low frequency signals. Background technique [0002] In the daily life and production process, it is often necessary to measure the instantaneous phase of the AC signal. The more accurate the measured instantaneous phase is, the better the application effect is. In the existing instantaneous phase measurement methods, most of them use the traditional zero-crossing method to measure the instantaneous phase of a certain signal. This algorithm is easy to implement, but it is easily affected by interference, which makes the measurement accuracy low. Contents of the invention [0003] The technical problem to be solved by the present invention is that the measurement accuracy of the instantaneous phase of the AC signal in the prior art is not accurate enough, and a method for measuring the ins...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is that the measurement accuracy of the instantaneous phase of the AC signal in the prior art is not accurate enough, and a method for measuring the instantaneous phase of the AC signal is proposed. Compared with the traditional zero-crossing method, the measured Accuracy, anti-interference and other aspects have been improved

Images