Ultra-high harmonic detection device and detection method based on compressed sensing

Abstract

The invention provides an ultra-high harmonic detection device and detection method based on compressed sensing. A sensing circuit is installed on a measurement end of a power distribution network, asignal outputted by the sensing circuit passes through a high-pass filter at first, then is mixed with a pseudo-random sequence outputted by a D / A module of a multifunctional data collection card andis sent to a low-pass filter, low-speed sampling of the signal is realized by an A / D module of the multifunctional data collection card, and finally, the signal is uploaded by a USB bus to an upper computer to complete the reconstruction and display of the signal. The high-pass filter is designed to be adjustable in gain and can also condition the signal in addition to filtering the power frequency and other low-frequency signal interference. The low-pass filter is designed to be achieve adjustable in cut-off frequency, and then variable compression ratio detection can be realized. A synchronous trigger module of the multifunctional data collection card can achieve D / A and A / D synchronization, and construct an observation matrix with a phase deviation of 0 to improve the reconstruction precision. The ultra-high harmonic detection device and detection method provided by the invention have the distinct advantages of greatly reducing the sampling frequency and the number of sampling points of a measurement device while ensuring that ultra-high harmonics and the spectral reconstruction thereof are correct.

Description

technical field [0001] The present invention relates to compressed sensing and harmonic detection, in particular to an ultra-high harmonic detection device and detection method based on compressed sensing. Background technique [0002] As an important infrastructure for economic and social development, distribution network plays a key role in realizing the strategic goals of smart grid and energy internet. Ultra-high harmonics are a new type of power quality problem derived from my country's new generation of intelligent distribution network, which will bring many adverse effects to electrical equipment and communications in the distribution network, and have attracted great attention from industry and academia. In June 2017, CIRED, an international power supply conference, specially set up innovation forums and technical lectures for ultra-high harmonic issues. [0003] At present, the harmonic measurement order of the mainstream harmonic measuring instruments in the marke...

AI Technical Summary

Problems solved by technology

[0003] At present, the harmonic measurement order of the mainstream harmonic measuring instruments in the market is not more than 50 times, and the anti-spectrum aliasing circuit of the instrument makes it impossible to measure harmonic components greater than 50 times

According to the Nyquist sampling theorem, in order to meet the measurement of ultra-high-order harmonics, the measurement times of harmonic measuring instruments are required to be greater than 100 times, which affects the ADC sampling rate, sampling number, and anti-aliasing filter order of the measuring instrument and cut-off frequency put forward higher requirements, increasing the cost of hardware implementation of harmonic measuring instruments

At the same time, real-time and high-speed sampling can easily lead to the generation of massive data, further causing a series of problems such as large amount of data calculation, difficult storage, and low transmission efficiency.

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