Measuring method, measuring device, measuring procedure and carrier for phase difference of three-phase circuit

Abstract

The invention adopts the symmetry of a three-phase circuit, and provides a phase difference measuring method for the three-phase symmetric circuit. The voltage and the current are sampled simultaneously to produce discrete signals of the three-phase voltage and the three-phase current, the mobile phase of current signals is scanned, the sum of the corresponding products of the three-phase voltage and the three-phase current is calculated, the mobile phase interval of the current with 90-degree voltage and current phase differences of corresponding phases is obtained through judging the absolute value of the sum of the products, and then the phase difference is obtained. The method needs not to depend on zero-crossing points of signals for calculation, the detected back-and-forth jittering of actual signals near the zero-crossing point caused by harmonic waves, noise, interference and other factors in actual applications cannot affect the calculation of the method; the requirements of the method for the signal cycle accuracy are low; and the algorithm in the method is simple, and the method has good real-time performance. The invention also provides a measuring device, a measuring procedure and a carrier for the phase difference of the three-phase circuit.

Description

technical field [0001] The invention relates to a phase difference measurement method, in particular to a phase difference measurement method and a measurement device used in a three-phase symmetrical circuit. Background technique [0002] The phase difference measurement of the same frequency signal is widely used in many fields such as power system and industrial automation. The power factor of various power system equipment and industrial automation equipment is one of the main performance parameters, and the measurement of power factor is actually for the Measurement of phase difference of voltage and current signals. [0003] There are many methods of measuring phase difference. In recent years, computer and digital signal processing technology have made great progress, and phase difference measurement is gradually developing towards digitalization. The advantages of digital measurement are low hardware cost and strong adaptability. For different measurement objects, on...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problems of the prior art that it is difficult to identify the zero-crossing point in practical applications and that Fourier has high requirements for accurate measurement of the period, the present invention provides a phase difference measurement method, a measurement device, and a measurement method suitable for three-phase symmetrical circuits. Program and carrier, adopting the present invention can eliminate the defect of zero-crossing interference, improve the measurement accuracy, and do not need to consider the accuracy of the signal period

Images