Method and device for measuring electrical signal phase of alternating current

Abstract

The invention discloses a method for measuring the phase position of AC electrical signals and a device thereof. The method comprises the following steps: the sine value and the cosine value of the phase position of the electrical signal are calculated by the instantaneous value of the electrical signal and the corresponding electrical signal change rate, and the phase position of the AC electrical signal is calculated according to the sine value and the cosine value of the phase position of the electrical signal. The device comprises a generation unit for the sine value and the cosine value of the phase position of the electrical signal that are connected with each other and a phase position calculation unit; the sine value and the cosine value of the phase position of the electrical signal is calculated by the generation unit for the sine value and the cosine value of the phase position of the electrical signal according to the instantaneous value of the electrical signal and the corresponding electrical signal change rate and output to the phase position calculation unit, the phase position of the AC electrical signal is calculated by the phase position calculation unit the sine value and the cosine value of the phase position of the electrical signal. The method for measuring the phase position and the device in the invention overcome the problem that the phase position ofsingle phase AC can not be calculated in real time with a universal method; in addition, the phase position measured by the method and the device of the invention is more stable and precise.

Description

Method and device for measuring electrical signal phase of alternating current technical field The invention relates to a method for measuring the electrical signal phase of alternating current, and also relates to a device for measuring the electrical signal phase of alternating current. Background technique The phase measurement of three-phase alternating current can usually obtain the phase through three-phase integrated vector and coordinate transformation. This method cannot calculate the phase for AC points with only single-phase voltage or phase loss. The measurement method of single-phase alternating current is usually to calculate the frequency and estimate the phase according to the zero-crossing point of its electrical signal. As shown in Figure 1, the specific implementation method is: through the comparator and related circuits, a rising edge signal is generated at the zero crossing of the electrical signal from negative to positive, and the time interval be...

AI Technical Summary

Problems solved by technology

The weak point of this prior art is: the collection of zero-crossing point must be accurate

If there is jitter near the zero-crossing point or the low sine degree causes the zero-crossing point voltage to be distorted, it will cause the rising edge signal to deviate from the actual zero-crossing point.

At this time, since the phases of other points are based on the zero-crossing point, this will lead to inaccurate judgment of the voltage phase within one cycle.

This will cause a relatively large error in the phase-lock adjustment

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