Parameter detection method for harmonic wave and indirect harmonic wave
A technology of parameter detection and harmonics, applied in spectrum analysis/Fourier analysis, etc., can solve problems such as inability to realize synchronous sampling, unsuitable for quantitative detection of each harmonic and inter-harmonic component parameters, large amount of calculation, etc.
Inactive Publication Date: 2011-04-27
HUNAN UNIV
View PDF0 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
However, in the presence of inter-harmonics, synchronous sampling is generally not possible, and the detection error of the traditional Fourier algorithm is very serious due to spectral leakage and fence effects
Corresponding improved methods such as windowing interpolation and spectrum correction can reduce the measurement error to some extent, but at the cost of longer measurement time and larger calculation amount; at the same time, it is necessary to construct a window function, which makes the analysis complicated
In addition, methods such as wavelet transform, modern spectrum estimation, and artificial intelligence are also used to analyze power harmonics and interharmonics, but their real-time performance is poor
The detection method based on the theory of instantaneous reactive power has good real-time performance, but it is not suitable for quantitative detection of each harmonic and inter-harmonic component parameters
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0061] Since the detection methods of harmonic and inter-harmonic parameters of voltage and current are basically the same, the following uses voltage as an example to illustrate the specific implementation method of harmonic and inter-harmonic detection.
[0062] step 1):
[0063] Digitally sample the voltage signal u (sampling frequency is 3200Hz, sampling period T s =1 / 3200 second), the sampling sequence is obtained:
[0064] u(k)=u(k·T s )k=0,1,2,...
[0065]Mathematically transform the sampled digital sequence to obtain a new sequence u 1 and u 2 :
[0066] u 1 ( k ) = u ( k ) cos ( kg ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
In order to overcome the disadvantage of existing detection method for harmonic wave and indirect harmonic wave, the invention provides a parameter detection method for harmonic wave and indirect harmonic wave, comprising the main realization steps as follows: 1) according to the characteristics of sinusoidal function and cosine function, transforming the fundamental wave weight and each sub-harmonic wave weight in voltage or current signal into direct current weight by mathematical transformation; 2) extracting the direct current weight with the low-pass filter; calculating the parameters, such as amplitude value and phase angle, of fundamental wave weight and each sub-harmonic wave weight; 3) subtracting fundamental wave and harmonic wave weights from the voltage signal so as to obtain the voltage or current signal which contains each indirect harmonic wave only; 4) obtaining the parameters of each indirect harmonic wave through maximum search of the amplitude spectrum. The method can rapidly and accurately detect parameters, such as harmonic wave, indirect harmonic wave frequency, amplitude value and phase angle.
Description
technical field [0001] This patent relates to a method for detecting harmonic and interharmonic parameters of voltage and current in a power system. Background technique [0002] According to the relevant standards of IEC and my country's national standards, the so-called harmonics are generally defined as the spectral components of integer multiples of the power frequency, and the components between the harmonics, that is, the components whose frequency is a non-integer multiple of the power frequency are called interharmonics. waves or fractional harmonics. Harmonics and interharmonics reduce the efficiency of production, transmission and use of electric energy, failure or burning of electrical equipment such as capacitors, inaccurate actions of relay protection and automatic devices, and so on. With the increase of large-capacity nonlinear electrical equipment, the harmonic and interharmonic pollution in the power grid is becoming more and more serious, which must be effe...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01R23/16
Inventor 江亚群何怡刚黄纯
Owner HUNAN UNIV