SV waveform comparison test method based on fast graphic fitting algorithm

Abstract

The invention relates to an SV waveform comparison test method based on a fast graphic fitting algorithm. According to the method, original graphic data of two SV waveform curves are obtained; the acquired original graphic data are normalized; a root mean square of the difference is calculated and iteration is carried out by one cycle; interpolation is carried out; small one of two minimum pointsis taken as a point obtained by the interpolation; m-times interpolation calculation is carried out; and a difference root mean square of two fitted SV waveforms is calculated and a sampling error ofa tested combined unit is obtained. According to the invention, with the bidirectional dichotomy fast interpolation method, the requirement of fast fitting of the graph is met and the precision is considered. For the waveform of 80-point sampling, the 0.244-microsecond calculation precision can be reached only by 10-times interpolation; and the accuracy requirement of the measurement can be met.

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...

AI Technical Summary

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

Images