Method for quickly measuring instantaneous phase of alternating current electrical signal

Abstract

The invention provides a method for quickly measuring an instantaneous phase of an alternating current electrical signal, which is applicable to the measurement of the instantaneous phase of a low-frequency signal. The method comprises the following steps of: pre-processing a sampling value of the alternating current electrical signal; directly calculating zero crossing point time when the alternating current electrical signals in previous cyclic waves of the alternating current electrical signal are changed from low to high; calculating the cycle of the alternating current electrical signal according to the zero crossing point; forecasting the cycle of the current cyclic waves; and finally calculating the instantaneous phase of the alternating current electrical signal according to the zero crossing point time, the forecast cycle of the alternating current electrical signal and the current time. Compared with the traditional zero crossing method, the method has the advantages that the alternating current electrical signal is not needed to be converted into a square wave, and the disadvantage of low interference resistance of the traditional zero crossing point detection is overcome, so the method is particularly suitable for instantaneous phase measurement of the alternating current electrical signal; moreover, the system is convenient to detect and the hardware expense is low; meanwhile, the method is implemented easily and rationally, and the data is accurate and reliable; and aspects such as measurement precision, interference resistance and the like are improved.

Description

technical field [0001] The invention relates to a method for quickly measuring the instantaneous phase of an alternating current signal, which can be used in new energy fields such as wind power generation and solar power generation. 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. What the industry needs is a software instantaneous phase measurement method with a small amount of computation and certain measurement accuracy. Contents of the invention [0003] The technical problem to be solved by the ...

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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 quickly measuring the instantaneous phase of the AC signal is proposed. Compared with the traditional zero-crossing method, the measurement The accuracy, anti-interference and other aspects have been improved to a certain extent

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