A novel detection method for improvement voltage fluctuation

2013 ◽  
Author(s):  
Abdollah Shokri ◽  
Hussain Sharif ◽  
Azah Mohammad ◽  
Shervin Shokri
Keyword(s):  
Detection Method ◽  
Voltage Fluctuation

Detection of Flicker Caused by Wind Farm Based on Mathematical Morphology Filter and Hilbert-Huang Transform

2013 ◽  
Vol 724-725 ◽  
pp. 555-560 ◽  
Author(s):  
Tong Yu Xu ◽  
Hong Fang Zhen ◽  
Li Di Wang
Keyword(s):  
Mathematical Morphology ◽  
Wind Farm ◽  
Detection Method ◽  
Processing Method ◽  
Voltage Fluctuation ◽  
Hilbert Huang Transform ◽  
Time Frequency ◽  
Signal Processing Method ◽  
Non Stationary Signal ◽  
Morphology Filter

Voltage fluctuation and flicker are among the most serious impacts of wind power generation on power quality. To assess and suppress voltage fluctuation and flicker, an accurate detection method is necessary. According to characteristics of flicker caused by wind farm, a systematic, accurate and fast flicker detection method was introduced. First, with Mathematical Morphology (MM) filter, noises contained in flicker signal were filtered out. Then to the filtered flicker curves, a track method based on Hilbert transform was adopted to pick out the flickers envelope which is the base of attaining relevant parameters of flicker. At last, the envelope was simultaneously analyzed in both time-domain and frequency-domain by a novel non-stationary signal processing method, the Hilbert-Huang transform (HHT). Simulations show that with this method, time, frequency and amplitude information of non-stationary flicker signals can be accurately detected and the proposed method is effective in the analysis of flickers caused by wind farm.

Voltage Flicker Detection Method Based on Teager Operator

2013 ◽  
Vol 677 ◽  
pp. 394-399
Author(s):  
Shuai Yuan ◽  
Jian Gang Bi
Keyword(s):  
Time Resolution ◽  
Detection Method ◽  
Detection Accuracy ◽  
Comparison Result ◽  
Voltage Fluctuation ◽  
Simulation Results ◽  
Voltage Flicker ◽  
The Hilbert Transform ◽  
Mathematical Derivation ◽  
Demodulation Method

Fast and accurately detection of voltage fluctuation components is very important to voltage flicker measurement. A novel voltage flicker demodulation algorithm based on Teager operator is proposed in this paper. The principle of the Teager operator demodulation approach is introduced, and the mathematical derivation of the proposed algorithm is described. The proposed algorithm is fast and requires only a few samples to calculates, therefore, it has excellent time resolution. The simulation results prove that the new algorithm can track the flicker signal of unifrequency or multifrequency amplitude modulation wave successfully. The comparison result of proposed method, the square demodulation method and the Hilbert transform demodulation method shows that the proposed method has obvious advantages of calculation speed and detection accuracy.

Solid-phase immunoelectron microscopy for rapid diagnosis of enteroviruses

1984 ◽  
Vol 42 ◽  
pp. 226-227 ◽  
Author(s):  
K. Pegg-Feige ◽  
F. W. Doane
Keyword(s):  
Electron Microscopy ◽  
Cell Culture ◽  
Immunoelectron Microscopy ◽  
Detection Method ◽  
Solid Phase ◽  
Protein A ◽  
Plant Viruses ◽  
Rapid Diagnosis ◽  
Virus Diagnosis ◽  
Antiviral Antibody

Immunoelectron microscopy (IEM) applied to rapid virus diagnosis offers a more sensitive detection method than direct electron microscopy (DEM), and can also be used to serotype viruses. One of several IEM techniques is that introduced by Derrick in 1972, in which antiviral antibody is attached to the support film of an EM specimen grid. Originally developed for plant viruses, it has recently been applied to several animal viruses, especially rotaviruses. We have investigated the use of this solid phase IEM technique (SPIEM) in detecting and identifying enteroviruses (in the form of crude cell culture isolates), and have compared it with a modified “SPIEM-SPA” method in which grids are coated with protein A from Staphylococcus aureus prior to exposure to antiserum.

A Fault Detection Approach Based on Sound Signal Analysis for Equipment Monitoring

2020 ◽  
pp. 129-139
Author(s):  
Weihai Sun ◽  
Lemei Han
Keyword(s):  
Fault Detection ◽  
Signal Analysis ◽  
Energy Analysis ◽  
Detection Method ◽  
Sound Signal ◽  
Practical Significance ◽  
Time Frequency ◽  
Detection Approach ◽  
Machine Fault ◽  
Learning Data

Machine fault detection has great practical significance. Compared with the detection method that requires external sensors, the detection of machine fault by sound signal does not need to destroy its structure. The current popular audio-based fault detection often needs a lot of learning data and complex learning process, and needs the support of known fault database. The fault detection method based on audio proposed in this paper only needs to ensure that the machine works normally in the first second. Through the correlation coefficient calculation, energy analysis, EMD and other methods to carry out time-frequency analysis of the subsequent collected sound signals, we can detect whether the machine has fault.

Development and Application of Quality Control System for Highway Subgrade Construction

2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Tong Wang
Keyword(s):  
Quality Control ◽  
Real Time ◽  
Detection Method ◽  
System Development ◽  
Effective Control ◽  
Construction Process ◽  
Development Mode ◽  
The Road ◽  
Whole Process

The compaction quality of the subgrade is directly related to the service life of the road. Effective control of the subgrade construction process is the key to ensuring the compaction quality of the subgrade. Therefore, real-time, comprehensive, rapid and accurate prediction of construction compaction quality through informatization detection method is an important guarantee for speeding up construction progress and ensuring subgrade compaction quality. Based on the function of the system, this paper puts forward the principle of system development and the development mode used in system development, and displays the development system in real-time to achieve the whole process control of subgrade construction quality.

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