Method for measuring instantaneous phase of alternating current

Abstract

The invention provides a method for measuring instantaneous phase of alternating current (AC), which is also suitable for measuring the instantaneous phase of a low frequency signal. The basic principle for the method comprises the following steps that: firstly, calculating zero crossing point (the zero crossing point when an AC electric signal changes from low to high) time for previous cycles of the alternating current through sampling values; secondly, calculating the period of the alternating current through the zero crossing point; thirdly, predicting the periods of the previous cycles; and finally, calculating the current phase of the alternating current through the zero crossing point time, the predicted alternating current period and the current time. Compared with a traditional zero crossing method, the alternating current does 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 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 technology of alternating current, which is also suitable for the instantaneous phase measurement of low frequency signals. Background technique [0002] In daily life and production process, it is often necessary to measure the instantaneous phase of alternating current. 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] Purpose of the invention: [0004] The main purpose of the present invention is to solve the inaccurate measurement accuracy of the instantaneous phase of the alternating current in the prior art, and propose a me...

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Problems solved by technology

In the existing instantaneous phase measurement methods, most of them use the traditional zero-crossing method to measure the instantaneous phas

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