SV Waveform Comparison Test Method Based on Fast Graph Fitting Algorithm

Abstract

The invention relates to a SV waveform comparison test method based on a fast graphic fitting algorithm, which acquires the original graphic data of two SV waveform curves, performs normalization processing on the acquired original graphic data, and calculates the root mean square of the difference And iterate a cycle, perform interpolation, take the smaller one of the two minimum points as the point obtained by interpolation, perform m interpolation calculations, and calculate the root mean square of the difference between the two fitted SV waveforms to obtain the measured merging unit sampling error. The two-way dichotomy fast interpolation method used in the present invention not only satisfies the demand for fast fitting of graphics, but also considers the accuracy. For the waveform sampled at 80 points, the calculation accuracy of 0.244 microseconds can be achieved only through 10 times of interpolation, which can fully meet the measurement accuracy requirements.

Description

technical field [0001] The invention belongs to the technical field of electric power automation, and in particular relates to an SV waveform comparison test method based on a fast graph fitting algorithm. Background technique [0002] As we all know, the power supply standard of China's power system is 50 Hz alternating current, which means that the voltage and current output by the power grid are constantly changing according to the amplitude of the sine wave in a period of 20 milliseconds, which is called the power waveform. In order to monitor the operation status of the power grid, it is necessary to collect the voltage and current in the power grid according to a certain ratio through voltage and current sensors to form simulated power grid status data. With the continuous development of power system equipment, power measurement and control equipment has gradually changed from the original analog acquisition method to digital acquisition method, that is, the voltage an...

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Problems solved by technology

[0006] At present, the SV waveform comparison method in the industry is: use the zero-crossing point as the starting point, and calculate the effective values ​​of multiple cycles for comparison. However, when the measured sampling value shows a symmetrical sawtooth waveform in this measurement method, the measurement error is relatively large.

There is also a method of calculating the tolerance of the zero-crossing point that can overcome the comparison error problem of the sawtooth waveform, but when the zero drift of the measured sampling value is too large, or the zero point offset is caused by inaccurate timing, the calculation error is also large; use graphic interpolation The method of moving fitting is limited to the selection of moving range, which will bring problems of slow convergence or low precision

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