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digital controller for hybrid filter in HVDC based on approximate inverse system

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Frontiers of Electrical and Electronic Engineering in China 2006年第4期1卷 367-370页

作者： SU Ling ZHAO Dong-yuan CHEN Jian-ye WANG Zan-ji Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Electric Power Research Institute Beijing 100085China

In order to eliminate the characteristic harmonics in high voltage direct current(HVDC)transmission systems and to simplify the analog controller structure,this paper proposes a new digital controller by adopting an approximate inverse system control strategy according to the frequency response characteristic of the hybrid power filter.The pro-posed digital controller is implemented with a TMS320C32 DSP,including a series of parallel digital band-pass filters,phase shifters and amplifiers.The results of both simulations based on PSCAD and experiments on a 30 kVA HVDC system prove that the proposed digital control system is sta-ble and efficient for eliminating the harmonics.

关键词： HVDC digital controller active power filter(APF) digital filter

Design of digital filter Based on VB and Matlab

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Design of Digital Filter Based on VB and Matlab

Time-frequency multiresolution of fault-generated transient signals in transmission lines using a morphological filter

2009 9th International Conference on Electronic Measurement & Instruments（ICEMI’2009）

作者： Xueling Bai Hongmei Zhang School of Power and Mechanical Engineering Wuhan University 430072 Wuhan China

The core of digital signal processing is the design of digital filter. At present, most digital filters are designed by Matlab, which is a high-performance numerical calculation software and provides a powerful function of graphical display. Matlab is widely used in engineering calculation, numerical analysis and other fields, but it is less able to develop interface. In this paper, a method of hybrid programming with VB and Matlab is introduced to design digital filter. The integrated software can take full advantages of VB and Matlab, and the process of realization indicates that this method is simple and convenient.

关键词： digital filter visual basic matlab component object model.

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Protection and Control of Modern Power Systems 2023年第2期8卷 85-98页

作者： Juan Carlos Quispe John Morales Eduardo Orduna Carlo Liebermann Michael Bruhns Peter Schegner Universidad Nacional de San Juan-CONICET San JuanArgentina Universidad Tecnológica del Perú LimaPerú Technical University of Dresden DresdenGermany

The ongoing transformation of electrical power systems highlights the weaknesses of the protection schemes of traditional devices because they are designed and configured according to traditional characteristics of the system.Therefore,this work proposes a new methodology to study the fault-generated high frequency transient signals in transmission lines through multiresolution analysis.The high frequency components are determined by a new digital filtering technique based on mathematical morphology theory and a spectral energy index.Consequently,wide spectra of signals in the time–frequency domain are obtained.The performance of this method is verified on an electrical power system modeled in ATP-Draw,where simulation and test signals are developed for different locations,fault resistances,inception angles,high frequency noises,sampling frequencies,types of faults,and shapes of the structuring element.The results show the characteristics of the fault such as the traveling wave frequency,location,and starting time.

关键词： digital filter High frequency Mathematical morphology Time–frequency Traveling waves

Determination of runoff coefficient(C)in catchments based on analysis of precipitation and flow events

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International Soil and Water Conservation Research 2022年第2期10卷 208-216页

作者： Ronalton Evandro Machado Tais Oliveira Cardoso Matheus Henrique Mortene Unicamp(University of Campinas)-College of Technology LimeiraSPBrazil

Runoff coefficient(C)values are tabulated and enshrined in hydrological engineering.These values are considered to be constant although they may not correspond to reality.In the same catchment,they may vary according to intensity,temporal and spatial distribution of precipitation events,humidity condi-tions,soil and land use.This study aimed to analyze extreme events of precipitation and their corre-sponding flows to obtain experimental runoff coefficients(C)and compare them with the tabulated values.The study was conducted in five experimental catchments in the state of S~ao Paulo,Brazil,with different land uses.The runoff coefficients(C)were obtained from the analysis of hydrograms and using a digital filter,which made it possible to separate the direct runoff from the total flow.We observed a different variation in runoff coefficient values between catchments compared to those obtained from the tables.The runoff coefficients had a high correlation with land use.In catchments with original vege-tation cover,such as Cerrado and forest,they varied little among the events analyzed,unlike the catchments where land use is diversified,with predominantly agricultural and urban occupation.

关键词： digital filter Hydrograms Hydrology Land use Watershed

A 16-bit cascaded sigma-delta pipeline A/D converter

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Journal of Semiconductors 2009年第5期30卷 103-108页

作者：李梁李儒章俞宙张加斌张俊安 National Key Laboratory of Analog ICs The 24th InstituteChina Electronics Technology Group Corporation

A low-noise cascaded multi-bit sigma-delta pipeline analog-to-digital converter （ADC） with a low over-sampling rate is presented. The architecture is composed of a 2-order 5-bit sigma-delta modulator and a cascaded 4-stage 12-bit pipelined ADC, and operates at a low 8X oversampling rate. The static and dynamic performances of the whole ADC can be improved by using dynamic element matching technique. The ADC operates at a 4 MHz clock rate and dissipates 300 mW at a 5 V/3 V analog/digital power supply. It is developed in a 0.35μm CMOS process and achieves an SNR of 82 dB.

关键词： multi-bit sigma-delta ADC oversampling pipeline digital filter switched capacitor

Design of complex FIR filters with arbitrary magnitude and group delay responses

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Journal of Systems Engineering and Electronics 2009年第5期20卷 942-947页

作者： Wang Xiaohua He Yigang Electrical and Information Engineering Coll. Changsha Univ. of Science & Technology Changsha 410077 P. R. China Electrical and Information Engineering Coll. Hunan Univ. Changsha 410082 P. R. China

To design approximately linear-phase complex coefficient finite impulse response （FIR） digital filters with arbitrary magnitude and group delay responses, a novel neural network approach is studied. The approach is based on a batch back-propagation neural network algorithm by directly minimizing the real magnitude error and phase error from the linear-phase to obtain the filter＇s coefficients. The approach can deal with both the real and complex coefficient FIR digital filters design problems. The main advantage of the proposed design method is the significant reduction in the group delay error. The effectiveness of the proposed method is illustrated with two optimal design examples.

关键词： signal processing digital filter neural network complex coefficient filter optimal design finite impulse response.

A 5 Gb/s low area CDR for embedded clock serial links

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Journal of Semiconductors 2015年第2期36卷 144-150页

作者：李优吕俊盛周玉梅赵建中陈玉虎张锋 Institute of Microelectronics Chinese Academy of Sciences

A multi-standard compatible clock and data recovery circuit （CDR） with a programmable equalizer and wide tracking range is presented. Considering the jitter performance, tracking range and chip area, the CDR employs a first-order digital loop filter, two 6-bit DACs and high linearity phase interpolators to achieve high phase resolution and low area. Meanwhile the tracking range is greater than 4-2200 ppm, making this proposed CDR suitable for the embedded clock serial links. A test chip was fabricated in the 55 nm CMOS process. The measurements show that the test chip can achieve BER 〈 10^-12 and meet the jitter tolerance specification. The test chip occupies 0.19 mma with a 0.0486 mm^2 CDR core, which only consumes 30 mW from a 1.2 V supply at 5 Gb/s.

关键词： clock and data recovery frequency and phase tracking digital filter bang bang PD phase interpolator

Practical Fast Computation of Zernike Moments

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Journal of Computer Science & Technology 2002年第2期17卷 181-188页

作者： Al-Rawi Mohammed 杨杰 Image Processing and Pattern Recognition Institute Shanghai Jiaotong University Shanghai 200030 P.R. China

The fast computation of Zernike moments from normalized geometric moments has been developed in this paper. The computation is multiplication free and only additions are needed to generate Zernike moments. Geometric moments are generated using Hatamian's filter up to high orders by a very simple and straightforward computation scheme. Other kinds of moments (e.g., Legendre, pseudo Zernike) can be computed using the same algorithm after giving the proper transformations that state their relations to geometric moments. Proper normalizations of geometric moments are necessary so that the method can be used in the efficient computation of Zernike moments. To ensure fair comparisons, recursive algorithms are used to generate Zernike polynomials and other coefficients. The computational complexity model and test programs show that the speed-up factor of the proposed algorithm is superior with respect to other fast and/or direct computations. It perhaps is the first time that Zernike moments can be computed in real time rates, which encourages the use of Zernike momentfeatures in different image retrieval systems that support huge databases such as the XM experimental model stated for the MPEG-7 experimental core. It is concluded that choosing direct computation would be impractical.

关键词： Zernike moment fast algorithm digital filter invariant pattern recognition image indexing

The Developmentand Clinical Application of Acoustical Technique in Hip Joint

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Journal of Huazhong University of Science and Technology(Medical Sciences) 2002年第4期22卷 362-366页

作者：黄晓琳邝适存郑振耀 DepartmentofRehabilitationMedicine DepartmentofRehabilitationSciences DepartmentofOrthopaedicsandTraumatology

A non- invasive acoustical system was developed for the measurement of transmission properties of acoustic waves in the hip joints.The instrumentation consisted of three sub- system s. An excitation system employed a vibratory force at the sacrum of the test subjects.A transduction system included a pair of identical microphones installed in the tubes of two stethoscopes,which were placed at the greater trochanters on both sides for picking up the acoustical signals transm it- ted across the hip joints.The data acquisition and analysis system was a portable signal analyzer with a program of dual channel digital filter for m easuring the power of acoustical signal in 1/ 3- oc- tave frequency bands.2 7normal adults,2 0 normal pre- school children and 4 0 norm al neonates were random ly selected for testing.Coherence function (CF) and discrepancy(D) was measured during the testing.Results from the three groups showed that there was a high coherence of the signals (CF>0 .9) and a sm all discrepancy(D0 .93) and a smaller discrepancy (D <2 d B) was observed.This study showed that the development of the acoustical technique pro- vided a practical m ethod with objective parameters.The results obtained in this study can offer a baseline for further investigation of hip disorders particularly those related to structural abnorm ali- ties of the hip.

关键词： hip joint acoustical technique digital filter