Synchronous rapid measuring method and device for ultralow frequency sinusoidal signal phase difference

Abstract

The invention relates to a synchronous rapid measuring method and device for ultralow frequency sinusoidal signal phase difference, belonging to the technical field of electronic measurement. By combining with the synchronous measurement technique and a virtual instrument technique, the phase value of a sinusoidal signal is obtained by utilizing partial wave form far less than a wave form period, so as to measure the ultralow frequency sinusoidal signal phase difference rapidly. The rapid measuring device comprises a first signal conditioning circuit, a second signal conditioning circuit, a first analog-to-digital conversion circuit, a second analog-digital conversion circuit, a first data register circuit, a second data register circuit, an interface circuit, a computer, an input and output circuit, a clock circuit and a logic control circuit. According to the invention, the phase difference of two paths of sinusoidal signals is obtained by utilizing the partial wave form of less than a period, thus avoiding multicycle wave from measurement and multiple-noise error influencing factors which exist in the traditional phase measurement method. The method and the device disclosed by the invention can be applied to making of ultralow frequency phase measurement systems and metering and aligning of ultralow frequency phase parameters.

Description

technical field [0001] The invention relates to a synchronous and rapid measurement method and device for an ultra-low frequency sinusoidal signal phase difference, belonging to the technical field of electronic measurement. Background technique [0002] Phase difference measurement and reproduction technology is one of the basic technologies in the fields of electronics, electromagnetism and radio measurement, which is of great significance and far-reaching influence. For example, the power factor in the AC electric energy measurement test needs to measure the phase difference between the two-phase or three-phase AC voltage and current to finally determine it. In fact, two channels (one voltage, one current) or six channels (three voltages, Three-way current) The phase difference between the sinusoidal signals. In addition, the time difference measurement in many occasions is obtained indirectly through the phase difference measurement, so the synchronous and accurate meas...

AI Technical Summary

Problems solved by technology

However, the rapid measurement of the phase difference of ultra-low frequency sinusoidal signals has always been a difficult problem. The main problem is that the usual phase difference measurement methods need to be carried out under the condition of obtaining multiple signal waveform cycles, and the ultra-low frequency signal cycle itself is very long, such as for The vibration period of the ultra-low frequency shaking table studied in earthquake monitoring and other researches can reach more than 1000s, and the lower limit of the frequency of a synthetic signal source is 1μHz, which makes it difficult to quickly obtain the ultra-low frequency sinusoidal phase difference, and the real-time refresh of the phase measurement value is also difficult to achieve

In addition, the accuracy of phase measurement is affected by many factors such as delay, noise, time base distortion, time base jitter, time drift, trigger noise, trigger jitter, sampling interval, and waveform distortion of different measurement channels, making it difficult to achieve high-precision measurement. It is also difficult to obtain high phase measurement resolution

[0003] Most of the existing phase measurement technologies are based on the principle of zero-crossing detection. The phase difference is calculated by the ratio of the time difference between the zero-crossing points of two sine waves to the signal period. In addition to the need to measure and obtain multiple signal waveform periods, its main disadvantages are: 1) The zero-crossing point is greatly affected by noise and distortion, and the jitter and fluctuation are large, so it is difficult to obtain high precision; 2) The zero-crossing point of the small phase difference is difficult to be distinguished, and the phase measurement resolution is limited; 3) When two sine waves When the amplitude difference is huge, the phase measurement is difficult to realize, or the error is huge; 4) The measurement of the ultra-low frequency sine wave phase difference cannot be realized quickly

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