Method for processing sample data based on waveform fitting and secondary sampling

Abstract

The invention discloses a method for processing sample data based on waveform fitting and secondary sampling. The method comprises the following steps: 1) determining the number of sample points which fulfill loss permission under a certain calculation accuracy condition according to the sample frequency of MU and the number of sample data points of transmission of each frame in a digital transformer station; 2) establishing a status word for data of each sample point in a primary buffer zone and a protective buffer zone, setting a 'valid' mark when the corresponding sample data is a real virtual value, and setting an 'invalid' mark when the value is invalid; 3) monitoring the communication condition of a device in real time, marking the state of the corresponding sample data into 'invalid' if a condition of frame drop/frame error happens; and 4) constructing an electricity fit waveform by cubic spline functions based on the primary sample data, and carrying out secondary sampling on the electricity fit waveform based on frequency tracking. The method solves the problem of insufficient capability of data processing of a protective device under a high speed sampling condition by using the method of waveform fitting based on the cubic spline functions and secondary sampling.

Description

technical field [0001] The invention relates to a sampling data processing method based on waveform fitting and re-sampling, which is suitable for a digital substation relay protection device and belongs to the technical field of power systems. Background technique [0002] The difference between the all-digital substation relay protection and the traditional relay protection is concentrated in two points: first, the data acquisition of the traditional relay protection is realized by the device itself, and the data sampling rate is low, and the frequency tracking technology is used to realize The sampling point of each cycle wave is relatively constant, which is convenient for data calculation. The digital protection sampling data is transmitted by the data acquisition and merging unit (MU) through communication. The sampling process is completed by the MU or electronic transformer. The data sampling frequency is high and the sampling frequency is constant (such as 5k / s, 10k...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is to effectively overcome the problem of insufficient data processing capability of the protection device in the case of high-speed sampling, and the protection lockout or loss of sampling data caused by the loss of sampling data after the data acquisition and transmission part is severely Delay phenomenon, to ensure the speed and accuracy of digital protection in complex situations

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