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High-resolution Reflection Spectroscopy ofCs D2 Line Studied by High-order-harmonic detection

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Chinese Journal of Lasers 2002年第2期11卷 51-54页

作者： ZHAO Yanting MA Weiguang XIAO Liantuan LI ChangyongZHANG Linjie JIA Suotang(Dept. of Electronics & Information Technology, Shanxi Univ. Key Laboratory for Quantum Optics of Ministry of Education , Taiyuan 030006, China) Dept. of Electronics & Information Technology Shanxi Univ. Key Laboratory for Quantum Optics of Ministry of Education Taiyuan 030006

In this paper, by numerical analysis the relationship of the modulation broaden index with modulation index using high-order-harmonic detection is investigated. Using the voltage modulation the 2f,4f and 6f harmonic signals about the reflection spectroscopy of 6S1/2(F = 4) →6P3/2 transition of the cesium D2 line are also be measured. The experimental results are in good agreement with the theoretical predictions. It is found that narrower line-width can be achieved by higher-harmonic detection than the line-width detected by direct absorption when the modulation index is smaller than 1.81, 2.98 and 4.14 for 2f, 4f, and 6f signals, respectively.

关键词： harmonic detection modulation broaden voltage modulation reflection spectroscopy

harmonic detection an AC excited generation system based on in-phase correlation filtering

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2002年第1期 66-72页

作者：贺益康孙丹王文举石赟

The paper reports results of investigation on the harmonic detection technique of a complicated power supply system such as an AC excited generation system, which has a variable fundamental frequency and low order harmonics with rich sub\|harmonics whose frequencies are lower than the fundamental one. The in\|phase correlation filtering technique, based on the frequency shifting principle, is proposed in this paper. Theoretical analysis and experimental results validate the effectiveness of this technique for the harmonic detections of AC excited generation systems.

关键词： in\|phase correlation filtering harmonic detection AC excited generation system

Influence of laser intensity in second-harmonic detection with tunable diode laser multi-pass absorption spectroscopy

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Chinese Physics B 2005年第9期14卷 1904-1909页

作者：阚瑞峰董凤忠张玉钧刘建国刘诚王敏高山虎陈军 Key Laboratory of Environmental Optics & Technology Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 China University of Science and Technology of China Hefei 230026 China

Tunable diode laser absorption spectroscopy （TDLAS） has been widely employed in atmospheric trace gases detection. The ratio of the second-harmonic signal to the intensity of laser beam incident to the multi-pass cell is proved to be proportional to the product of the path length and the gas concentration under any condition. A new calibration method based on this relation in TDLAS system for the measurement of trace gas concentration is proposed for the first time. The detection limit and the sensitivity of the system are below 110 and 31ppbv （parts-per-billion in volume）, respectively.

关键词： tunable diode laser absorption spectroscopy multi-pass cell harmonic detection wavelength modulation

In-Situ Domestic Load harmonic detection and Reduction Based on GLRM Algorithm for Optimum Filter Excerpt

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Circuits and Systems 2016年第9期7卷 2095-2108页

作者： Deepthi Joseph N. Kalaiarasi K. Rajan Department of Electrical and Electronics Engineering Vel Tech Engineering College Anna University Chennai India Department of Electrical and Electronics Engineering R. M. K. C. E. T Anna University Chennai India

Power Quality measures the reliable operation between the system and to the connected loads of same system. A poor power quality causes physical damage to the equipment and also results in lower productivity with increase in energy costs. Power disturbances range from micro seconds to hours and the prolonged disturbances in hours would damage the equipments. The power quality decreases due to growth of nonlinear loads in domestic appliances, such as home Uninterrupted Power Supplies (UPS), Induction stove, Television etc. Nowadays Domestic loads are controlled or powered with power electronic devices. The power electronic devices with Direct Current (DC) components generate high frequency signal for DC-Alternating Current (AC) conversion. The conversion introduces multiple frequencies in the AC power supply. The multiple frequencies in AC power supply are called as harmonics. The harmonics in AC supply affects the lifetime of home appliances, consumes more electric current, affects the power factor, transformer efficiency, and other electricity supply systems. Till now, to avoid harmonics, the filters are erected only in industrial loads or in the substations. In this paper a novel method to detect and control harmonics in domestic appliances is proposed. harmonic control with various filters in the filter bank, based on detection of harmonic voltage let out from the domestic appliances for power saving. To select the appropriate filter to improve power quality, we apply a novel Genetic Algorithm based Linear Regression Method (GLRM) algorithm for optimum Filter Selection. From the results we were able to reduce the total harmonic distortion level to 3.68%.The current consumption of each household appliance is reduced considerably and finally the electricity bill is reduced to 15% and overall system efficiency improves to 85%.

关键词： Power Quality Domestic Appliances harmonic detection harmonic Control Filter GLRM Algorithm

Power System harmonic detection Using Frequency-Domain Interpolation Wavelet Transform

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Journal of Electronic Science and Technology of China 2005年第3期3卷 245-248页

作者：杜天军陈光 School of Automation Engineering University of Electronic Science and Technology of China Chengdu 61005 China

Aiming at harmonic detection, fast Fourier transform can only detect integer harmonics precisely, short time Fourier transform can detect non-integer harmonics with low resolution, and some former wavelet based methods have no aliasing-reduction scheme which result in low measurement precision and poor robustness. A frequency-domain interpolation algorithm to detect harmonics is proposed by choosing Shannon wavelet. Shannon wavelet is an orthogonal wavelet possessing best ideal frequency domain localization ability, it can restrict wavelet abasing but bring about Gibbs oscillation phenomenon simultaneously. An interpolation algorithm is developed to overcome this problem. Simulation reveals that the proposed method can effectively cancel aliasing, spectral leakage and Gibbs phenomenon, so it provides an effective means for power system harmonic analysis.

关键词： wavelet transform frequency-domain interpolation wavelet aliasing harmonic detection

Modeling and Simulation of Power Grid Voltage harmonic detection Method Based on the Improved Wavelet Packet Transform

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Modeling and Simulation of Power Grid Voltage Harmonic Detec...

Power harmonic detection Method Based on Dual HSMW Window FFT/ap FFT Comprehensive Phase Difference

第40届中国控制会议

作者： Jian Guo Chao Jiang Chenxi Guan Tao Zhang Jiangkun Pu College of Mechanical and Electrical Engineering Harbin Engineering University

In order to solve the existing problems of the grid voltage harmonic detection algorithms, such as low precision,complicated calculation, the harmonic detection algorithm based on wavelet packed transform is proposed in this paper. The filtering algorithm of an improved wavelet packet transform is also presented by combining the wavelet packet transform with two-stage method. That is to say, on the basic of wavelet packet transform, the standard waveform of the fundamental harmonic can be obtained by taking compound decomposition algorithm. And then the amplitude of the fundamental and each odd harmonic is also obtained through the effective value module. The modeling and simulation analysis of the proposed algorithm are performed. The simulation results show that the improved detection algorithm can effectively filter out the harmonics and obtain a complete fundamental wave. The obtained fundamental waveform meets the electricity requirements.

关键词： Wavelet Transform Wavelet Packet Algorithm Grid Voltage harmonic detection

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Power Harmonic Detection Method Based on Dual HSMW Window FF...

UPQC harmonic detection Algorithm Based on Improved p-q Theory and Design of Low-Pass Filter

第40届中国控制会议

作者： Yong Shao Yufan Yao Huafeng Liu Rong Lv Peng Zan School of Mechatronics Engineer and Automation of Shanghai University Shanghai Key Laboratory of Power Station Automation Technology

Aiming at the use of traditional Fourier transform（FFT） for harmonic detection, due to non-synchronous sampling and non-integral period truncation, which will affect the calculation accuracy of each harmonic, this paper proposes a dual Hanning self-multiplication window（HSMW） and FFT/ap FFT integrated phase difference power harmonic detection *** algorithm combines the traditional FFT and ap FFT phase difference method, which has the advantage that the amplitude and phase can be obtained by accessing only one spectral line. At the same time, a dual HSMW window is designed to suppress spectral leakage. The simulation comparison experiment with traditional FFT spectrum analysis and dual Hanning window FFT/ap FFT integrated phase difference method verifies the effectiveness and stability of the algorithm proposed in this paper.

关键词： HSMW FFT/ap FFT integrated phase difference method Spectrum analysis harmonic detection

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UPQC Harmonic Detection Algorithm Based on Improved p-q Theo...

Experimental　investigation　of　the　sub-Doppler　transmission　spectroscopy　in　a　thin　vapour　layer　at　room　temperature

第30届中国控制与决策会议

作者： Silun Shen Hong Zheng Yong Lin Wei Zhao School of Electrical and Information Engineering Jiangsu University Jiangsu Key Laboratory of Drive and Intelligent Control for Electric Vehicle

With the development of smart grid, the power quality problems are getting more and more serious, such as voltage sag/swell, voltage and current harmonic distortion and so on. The unified power quality conditioner（UPQC） has been used to improve multiple power quality problems which is an important developmental trend of current power system. In this paper, a harmonic comprehensive detection algorithm based on improve p-q theory is proposed to be applied to the UPQC. It can quickly and accurately detect a variety of power quality problems such as harmonic currents, voltage sag/swell, unbalanced three-phase voltage. Furthermore, an enhanced low-pass filter is designed to improved accuracy of low-pass filter in this harmonic detection algorithm. Simulation results are presented to verify the rationality of this detection method and the performance of the enhanced low-pass filter.

关键词： UPQC harmonic detection p-q theory Low-pass filter

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Chinese Physics B 2004年第9期13卷 1414-1417页

作者：赵延霆赵建明黄涛肖连团贾锁堂 StateKeyLaboratoryofQuantumOpticsandQuantumOpticsDevices CollegeofPhysicsandElectronicsEngineeringShanxiUniversityTaiyuan030006China

The sub-Doppler transmission spectrum in a thin vapour layer (about 150μm) was observed at room temperature using the wavelength modulation technology. The absorption signal and its second-order harmonic were detected with an external-cavity diode laser. A sub-Doppler spectrum corresponding to resonant transitions of the caesium D2 line(6S1/2 →6P3/2) was demonstrated. The dependence of the transmission signal on the intensity of the laser was also investigated.

关键词： thin vapour layer sub-Doppler technique harmonic detection