Frequency measuring method, system amd device and computer readable storage medium

Abstract

The invention discloses a frequency measuring method. The method comprises the steps that a measured signal is sampled according to a preset sampling frequency to acquire a sampling value, and the estimated frequency of the measured signal under sampling numbers of the power frequency whole cycle is calculated according to the sampling value; the range of actual whole cycle sampling numbers is determined according to the estimated frequency; the sum of the sample value of each segment corresponding to each whole cycle sampling number in the range is calculated; the whole cycle sampling numbercorresponding to the sum value closest to the zero value is selected as the actual whole cycle sampling number; and the measured frequency of the measured signal under the actual whole cycle samplingnumber is calculated according to the sample value. The frequency measuring method can reduce or even eliminate the influence of signal spectrum leakage on frequency measurement while taking into account the requirements of calculation accuracy and calculation speed, improves the frequency measurement accuracy, and meets measurement requirements. The invention further discloses a frequency measuring system and device and a computer readable storage medium, which have the above technical effects.

Description

technical field [0001] The present invention relates to the technical field of power systems, in particular to a frequency measurement method, and also to a frequency measurement system, device and computer-readable storage medium. Background technique [0002] Frequency is one of the important power quality indicators in power systems. Timely and accurate frequency measurement can provide an effective data basis for power grid stability monitoring systems, synchrophasor measurement systems, and power grid control strategies. There are many methods for measuring frequency at present, such as zero-crossing method, least square method, analytical method, DFT algorithm and so on. Among them, the DFT algorithm has been widely used in the fields of power system frequency measurement and phasor measurement because of its perfect filtering performance. However, when the grid frequency shifts, the spectrum leakage phenomenon is particularly serious. In view of this situation, the c...

AI Technical Summary

Problems solved by technology

However, when the grid frequency shifts, the spectrum leakage phenomenon is particularly serious. In view of this situation, the current processing methods are generally divided into two types: one is to take the average value of the measurement frequency, which will increase the delay; the other is to Using the FFT algorithm with window interpolation, the FFT algorithm has a large amount of calculation, which affects the calculation speed

Therefore, regardless of the Fourier algorithm or the improved algorithm of the Fourier algorithm, it is impossible to take into account the calculation accuracy, calculation speed, delay and other indicators.

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