Frequency conversion method for implementing multi-sampling rate signal by using narrow band filtering in electricity grid

Abstract

The invention belongs to the technical field of digital transforming plant and power grid wide area measurement, and relates to a method for converting frequency of a multi-rate signal by narrow band filtering. The method adopts a narrow band filter based on full-wave Fourier to carry out low-pass filtering when utilizing extraction and insertion to realize sampling rate conversion and unification, is applicable to devices for monitoring, protecting and controlling a power system in real time, and can simultaneously complete frequency normalization and extraction of useful signals. The methodcan extract the signals with useful frequency (such as fundamental component) when converting sampling frequency, can filter the signals with useless frequency (such as weakened non-cyclical component and every upper harmonic), and can completely avoid generating aliasing and mirror image of the sampling frequency.

Description

A frequency conversion method for multi-sampling rate signals using narrow-band filtering in power grids technical field The invention relates to the technical field of wide-area measurement of digital substations and power grids, in particular to a method for converting and unifying sampling frequencies of multi-sampling rate signals for real-time monitoring, protection and control. Background technique The digital substation based on the IEC61850 standard has entered the stage of practical application. The primary and secondary equipment in the substation have been digitized, and have a unified data model and communication platform for the whole station. On the basis of this platform, the interoperability between intelligent devices can be realized. . At the same time, with the application of the Global Positioning System (GPS) in the power system, the development of computer networks and communications, a real-time monitoring system based on synchrophasor measurement te...

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Problems solved by technology

Zhou Bin and Zhang He wrote the interface technology of sampling value of substation intelligent equipment based on electronic transformer (Jiangsu Electrical Engineering, 2007, 26(2): 37-39), and proposed a Lagrange interpolation (linear interpolation) method, but when the Larger errors will be generated when the harmonic order in the band is higher; the extraction, interpolation method and sequence of digital signals written by Zheng Shilin (Communication Technology, 2001, (7): 106-108) From the perspective of signal fidelity, the average The interpolation method realizes the conversion of the sampling frequency, but the frequency of the interpolation method is increased by 2l times

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