Real-time detection device for power grid voltage harmonics

Abstract

The invention, which relates to the technical field of voltage harmonic detection, discloses a real-time detection device of power grid voltage harmonics. According to the device, with a fast Fouriertransform (FFT) module and a bispectral line interpolation algorithm, time-domain signal change to frequency-domain processing is carried out on a to-be-detected signal and then a frequency peak valueis searched by three points; the frequency and amplitude of each frequency point are analyzed, windowing is carried out on a signal by adopting a Kaisephine window of which beta is equal to 4pi, andthe frequency precision generated by frequency domain discretization is corrected by applying the bispectral line interpolation algorithm; and the frequency component and percentage of the voltage ina power grid are analyzed by utilizing Fourier transform. Data are provided for governance of power grid harmonics by detecting frequency components and amplitudes of voltage harmonics in a power grid.

Description

technical field [0001] A real-time detection device for grid voltage harmonics, which uses Fourier transform to analyze the frequency components and percentages of voltage in the grid, and detects the frequency components and amplitudes of voltage harmonics in the grid to obtain grid harmonics The governance provides data, and the invention relates to the technical field of voltage harmonic detection. Background technique [0002] The method of analog filter is the earliest electric energy harmonic detection method. The principle of harmonic detection is to use the filter to filter out other frequency components other than the harmonic to be detected, so as to obtain the harmonic frequency component to be detected; The advantage of the filter detection method is that it is easy to implement and simple in structure, but it also has many defects that cannot be ignored, such as huge errors in the detection results, poor real-time performance, and variable fundamental frequency ...

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Problems solved by technology

[0002] The method of analog filter is the earliest electric energy harmonic detection method. The principle of harmonic detection is to use the filter to filter out other frequency components other than the harmonic to be detected, so as to obtain the harmonic frequency component to be detected; The advantage of the filter detection method is that it is easy to implement and simple in structure, but it also has many defects that cannot be ignored, such as huge errors in the detection results, poor real-time performance, and variable fundamental frequency of the power grid. If a fixed frequency filter is used Harmonics that you want to measure may be filtered out, resulting in erroneous measurements

[0003] With the development of science and technology, many technologies have been developed, among which artificial neural network is one of the best; the main principle of neural network is to simulate the nerve cells of animals, and then conduct large-scale training to make it have memory and learning ability. The artificial neural network can improve the weight of its own neural network according to the collected samples, so that it can continuously learn according to the actual situation to adapt to the change of current or voltage in the power grid, but the artificial neural network still has many defects, such as requiring a large number of Only a large number of samples can guarantee the accuracy of the results, the amount of calculation is huge, and the speed of data processing does not have an advantage, etc.

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