Research of a New Power Quality Detection System Based on ARM

2014 ◽  
Vol 568-570 ◽  
pp. 1825-1833
Author(s):  
Yan Qing Peng ◽  
Feng Wang ◽  
Ji Zhang ◽  
Jia Li ◽  
Da Min Zhang

Based on the comparative analysis of the fast Fourier transform (FFT), the short-time Fourier transform (STFT), the wavelet transform (WT) and other power quality detection algorithms, this paper puts forward to a new power quality detection algorithm which combines the Fourier transform with the wavelet transform. The transient as well as the steady state signals are separated on the basis that the wavelet transform is sensitive to the singular signals. The presented algorithm detects a variety of harmonic parameters of the gird after the separation of steady state signals is finished by fast Fourier transform. A new power quality detection system is then designed based on the core chip of S3C2440A, and the algorithm which is ARM-9 based is transplanted into the embedded Linux operating system to carry out the experiments. Analysis of the experimental data shows the detection algorithm is reliable by Fourier transform and wavelet transform.

Author(s):  
Abdul Hadi Bin Mustapha ◽  
R Hamdan ◽  
F. H. Mohd Noh ◽  
N. A. Zambri ◽  
M. H. A. Jalil ◽  
...  

<span lang="EN-GB">The importance of supplying undisturbed electricity keep increasing due to modernization and lifestyle. Any disturbance in the power system may lead to discontinuation and degradation in the power quality. Therefore, detecting fault, fault type and fault location is a major issue in power transmission system in order to ensure reliable power delivery system. This paper will compare two prominent methods to estimate the fault location of double circuit transmission line. Those methods are Discrete Wavelet Transform algorithm and Fast Fourier Transform algorithm. Simulations has been carried out in MATLAB/Simulink and a variety of fault has been imposed in order to analyse the capability and accuracy of the fault location detection algorithm. Results obtained portrayed that both algorithms provide good performance in estimating the fault location. However, the maximum percentage error produced by the Discrete Wavelet Transform is only 0.25%, 0.6% lower than maximum error produces by Fast Fourier Transform algorithm. As a conclusion, Discrete Wavelet Transform possesses better capability to estimate fault location as compared to Fast Fourier Transform algorithm.</span>


2013 ◽  
Vol 378 ◽  
pp. 335-339
Author(s):  
Xin Liang Yin ◽  
Gui Tang Wang ◽  
Zhi Wen Feng ◽  
Xiong Hui Lai

Voltage sag belongs to a kind of transient power quality problems, it possesses short mutations, non-stationary characteristics and the detection on the interference is difficult. Wavelet transform is a better signal analysis method and it is very suitable for analysis of mutations in the signal. Compared with traditional wavelet transform algorithm, Wavelet transform algorithm does not depend on the ascension of the Fourier transform and it reduces the computation complexity, so it is very suitable for hardware implementation. This paper introduces a design based on 9/7 of lifting wavelet transform of the voltage sag detection algorithm, and realized in the FPGA and modeling the transient power quality signal in the Matlab. To make hardware implementation easier, a series of optimization to the coefficient of ascension of 9/7 of lifting wavelet transform was carried out. The results show that 9/7 of the lifting wavelet transform algorithm can effectively test the end time of the voltage sag happens.


2012 ◽  
Vol 195-196 ◽  
pp. 777-782 ◽  
Author(s):  
Yun Dong Cao ◽  
Xing Gang Chen

In view of the problem that harmonics analysis by fast Fourier Transform can appear a higher error and the serious phenomenon of harmonics leakage and fence, it is put forward that a improved arithmetic that FFT of special Hanning interpolation combined with wavelet transform. It is proved by theory analysis and simulation calculation that: FFT arithmetic of special Hanning interpolation can raise the precision of steady-state harmonics analysis validly. And wavelet transform arithmetic can analyze time-varying harmonics and sudden-changing harmonics precisely. The arithmetic of wavelet transform combined with FFT can remedy the defects of harmonics analysis by FFT and analyze harmonics precisely, timely and validly.


2014 ◽  
Vol 530-531 ◽  
pp. 705-708
Author(s):  
Yao Meng

This paper first engine starting defense from Intrusion Detection, Intrusion detection engine analyzes the hardware platform, the overall structure of the technology and the design of the overall structure of the plug, which on the whole structure from intrusion defense systems were designed; then described in detail improved DDOS attack detection algorithm design thesis, and the design of anomaly detection algorithms.


2008 ◽  
Vol 3 (4) ◽  
pp. 74-86
Author(s):  
Boris A. Knyazev ◽  
Valeriy S. Cherkasskij

The article is intended to the students, who make their first steps in the application of the Fourier transform to physics problems. We examine several elementary examples from the signal theory and classic optics to show relation between continuous and discrete Fourier transform. Recipes for correct interpretation of the results of FDFT (Fast Discrete Fourier Transform) obtained with the commonly used application programs (Matlab, Mathcad, Mathematica) are given.


2011 ◽  
Vol 204-210 ◽  
pp. 1386-1389
Author(s):  
Deng Yin Zhang ◽  
Li Xiao ◽  
Shun Rong Bo

The existing edge detection algorithms with wavelet transform need to artificially set the threshold value and are lack of flexibility.To salve the limitations, in this paper, we propose a WT(wavelet transform)-based edge detection algorithm with adaptive threshold, which uses threshold value iteration method to achieve adaptive threshold setting. Comparison of experiment results for the CT image shows that the method which improve the clarity and continuity of the image edge can effectively distinguish edge and noise, and get more completely information of the edge. It has good application value in the fields of medical clinical diagnosis and image processing.


1962 ◽  
Vol 52 (4) ◽  
pp. 767-779
Author(s):  
A. F. Espinosa ◽  
G. H. Sutton ◽  
H. J. Miller

abstract A transient technique for seismograph calibration was developed and tested by a variety of methods. In the application of this technique a known transient in the form of an electrical signal is injected, through (a) a Willmore-type calibration bridge or (b) an independent coil, into the seismometer and the corresponding output transient of the system is recorded. The ratio of the Fourier transform of this transient to that of the input pulse yields phase and relative amplitude response of the seismograph as a function of period. Absolute amplitude response may be calculated if two easily determined constants of the seismometer are known. This technique makes practical the daily calibration of continuously-recording seismographs without disturbing the instruments more than a very few minutes. The transient technique was tested and proven satisfactory with results of more conventional steady-state methods, using both digital and analog analyses of the output transients. A variety of output transients corresponding to various theoretical response curves has been calculated for two standard input transients. By comparison of the calculated output transients with experimental results it is possible to obtain the response of the instrument with considerable precision quickly and without computation.


Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4295 ◽  
Author(s):  
Bong-seok Kim ◽  
Youngseok Jin ◽  
Jonghun Lee ◽  
Sangdong Kim

This paper proposes a low complexity multiple-signal-classifier (MUSIC)-based direction-of-arrival (DOA) detection algorithm for frequency-modulated continuous-wave (FMCW) vital radars. In order to reduce redundant complexity, the proposed algorithm employs characteristics of distance between adjacent arrays having trade-offs between field of view (FOV) and resolution performance. First, the proposed algorithm performs coarse DOA estimation using fast Fourier transform. On the basis of the coarse DOA estimation, the number of channels as input of the MUSIC algorithm are selected. If the estimated DOA is smaller than 30°, it implies that there is an FOV margin. Therefore, the proposed algorithm employs only half of the channels, that is, it is the same as doubling the spacing between arrays. By doing so, the proposed algorithm achieves more than 40% complexity reduction compared to the conventional MUSIC algorithm while achieving similar performance. By experiments, it is shown that the proposed algorithm despite the low complexity is enable to distinguish the adjacent DOA in a practical environment.


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