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en: Locating Multiple Partial Discharge Sources using MAP Estimation and Ray Tracing

en: IEEJ Transactions on Electrical and Electronic Engineering (TEEE)


en: Internal Defect Position Evaluation of Ground Coil by Detecting Electromagnetic Waves from Partial Discharge

en: Because a huge number of ground coils are used outdoors for an extended period of time in the superconducting magnetically levitated transportation (Maglev) system, high reliability of ground coils and the cost reduction are required. The propulsion coil especially needs the high insulation stability as high-voltage equipment. Because the ground coil, which is made with the resin-molded winding, does not have a core in the structure, the ground coil must be exposed to the electromagnetic force directly. Therefore, there is a possibility that minute defects in the molded resin of the ground coil may expand, become apparent, and lead to the deterioration of insulation stability. In this paper, we examined the insulation diagnosis to assess the existence/nonexistence of the inside defect and locate the defect by setting a simulated void-defect inside the molded resin of the ground coil and detecting the electromagnetic waves effectively that are emitted from a partial discharge at the defect point.

en: IEEJ Transactions on Fundamentals and Materials


en: Simulation on Locating Partial Discharge Source Occurring on Distribution Line by Estimating the DOA of Emitted EM Waves

ja: IEEJ Transactions on Electrical and Electronic Engineering (TEEE)


en: Simulation Study on Multi-Pulse Phenomena of Atmospheric Pressure Argon Dielectric Barrier Discharge

en: Plasma Science and Technology

ja: Plasma Science and Technology


en: Estimation of DOAs of EM Waves Emitted from Multiple Partial Discharge Sources in Free Space by Using Wideband Siganl Subspace Methods

en: Journal of International Council on Electrical Engineering


en: Effect of Spectrum Analyzer's Impulse Bandwidth on the Measurement of EM Waves Emitted from Partial Discharges in Multipath-Rich Environment


en: Localization of a Partial Discharge Source Using Maximum Likelihood Estimation


en: Locating Partial Discharge Source Occurring on Distribution Line by Using FDTD and TDOA Methods

ja: IEEJ Transactions on Fundamentals and Materials


en: Estimation of the Number of Partial Discharge Sources Using Multichannel Blind Deconvolution of Electromagnetic Waves

en: We propose a method to estimate the number of partial discharge sources in multipath environment using the multichannel blind deconvolution method called the super-exponential deflation method. Blind deconvolution is a method of recovering transmitted signals from only observed signals without any a priori knowledge of the source signals. The deflation approach can extract a source signal which is non-Gaussian from the observed signals one by one. The deflation approach is repeated until all non-Gaussian signals are extracted, in which case the input signals become close to Gaussian noise. The eigenvalues of the spatial correlation matrix of the input signals indicate whether the input signals are Gaussian noise or not. Thus, the proposed method estimates the number of PD sources by repeating the deflation approach and analyzing the eigenvalues.


en: Development of Recursive Interpolated D/FFT for On-line and Highly Accurate Frequency Analysis


en: Location Technique for Multiple Partial Discharge Sources using Independent Component Analysis and Direction of Arrival Method of Electromagnetic Waves based on Bayesian Network

ja: 独立成分分析とベイジアンネットを適用した電磁波到来角推定法による複数部分放電源の位置標定

en: We propose the new locating method for multiple partial discharge sources using independent component analysis (ICA) and direction of arrival method of electromagnetic (EM) waves based on Bayesian Network. The proposed method consists of the following steps. First, the observed signals are converted from the time domain to the frequency domain through the short time Fourier transform (STFT). As the result of this process, ICA for convolved mixture turns into ICA for instantaneous mixture. In order to separate mixed signals, we use the fast ICA algorithm (FastICA) that is based on negentropy as a measure of nongaussianity. Next, we apply the direction of arrival method of EM waves using Bayesian Network to the separated source signals by ICA. Signal sources are estimated by calculating intersection point from the arrival angle. Simulation results showed that our method located multiple signal sources when the observed signals were the convolved mixture of original sources.

en: IEEJ Transactions on Power and Energy

ja: 電気学会論文誌B (電力・エネルギー部門誌)


en: Rotor Vibration Diagnosis using Wavelet Analysis (Detection of Rubbing and Lack of Lubricant in Bearings)

ja: ウェーブレット解析を利用した軸振動診断(ラビングと軸受給油不足の検出)

en: We developed a diagnosis method for unsteady rotor vibration using vibration repetition calculated from the results of wavelet analysis. In previous research, we compared measured vibration repetition with pre-measured abnormal vibration repetition. To improve the reliability of the diagnosis, we used differential vibration repetition, which is calculated by subtracting pre-measured normal vibration repetition from measured one. We measured abnormal vibration and applied the diagnosis method to the measured vibration, to determine the reliability of the method. An unsteady natural frequency vibration started, when rubbing on a rotor occurred. As lubricant in the bearings was reduced, a steady natural frequency vibration occurred, and it changed to an unsteady low frequency vibration. A steady super-harmonic vibration occurred when most of the lubricant in the bearings was absent. The reliability of the diagnosis was improved using deferential vibration repetition.

en: Transactions of The Japan Society of Mechanical Engineers, Series C

ja: 日本機械学会論文集(C編)


en: Diagnosis using Wavelet Analysis for Vibration when Lubricant in Bearings is Reduced

ja: ウェーブレット解析による軸受給油不足時の振動診断

ja: 日本機械学会論文集(C編)


en: Time-Frequency Visualization of Vibration Phenomena generated on Turbine Model using Wavelet Transform

ja: タービンモデルにおける振動現象のウェーブレット変換による時間周波数可視化

en: In this paper we presented results of fundamental study to introduce the wavelet transform to vibration diagnosis for a turbine. It is required to detect typical vibration of the turbine accurately. The wavelet transform is used in many fields because it is able to visualize a phenomenon in a time-frequency domain. Modern power plants usually use one-high pressure and one or two lower pressure turbines. We made a turbine model with 3 rotors supported with journal bearings to simulate contact vibration, oil whip, and clearance vibration. The vibration phenomena were measured with vertical and horizontal displacement meters at the rotors, and with vertical and horizontal accelerometers at the bearings. The vibration phenomena were visualized in the time-frequency domain by the wavelet transform. This paper especially shows the results of the acceleration signals. It is found that the dynamic spectra obtained by the wavelet transform of the acceleration signals are different for each vibration. Therefore, this method is able to distinguish the vibration phenomena. And furthermore, the contact point is localized by the proposed method.

ja: 電気学会論文誌B (電力・エネルギー部門誌)


en: Fundamental Study on Direction Finding Technique for Electromagnetic Waves Emitted from a Partial Discharge using Bayesian Network

ja: ベイジアンネットによる部分放電放射電磁波の方位角推定法に関する基礎研究

en: We propose a new method for finding the direction of arrival (DOA) of the electromagnetic waves emitted from a partial discharge source using Bayesian Network. The time delay between two antennas computed from digital data generally has error because of the effect of sampling time. Therefore the angle of arrival estimated from the time delay also has the estimation error. In order to deal with the estimation error, we investigate a probabilistic method of reasoning with uncertain information. In this method, system provides the probabilities of each angle based on Bayes Theorem. From results of a simulation and an experiment, we have confirmed that our proposed method is able to estimate the angle of arrival of the electromagnetic waves.

ja: 電気学会論文誌B (電力・エネルギー部門誌)


en: Fundamental Study on Vibration Diagnosis for High Speed Rotational Machine using Wavelet Transform

ja: ウェーブレット変換による高速回転機振動診断のための基礎研究

en: In this paper we presented results of fundamental study to introduce the wavelet transform to vibration diagnosis for high-speed rotational machine such as steam turbine, gas turbine, and generator and so on. It is required to detect and distinguish typical vibration of high-speed rotational machine accurately in order to diagnose the machine. The wavelet transform is used in many fields because it is able to visualize phenomenon in time-frequency domain and to detect the beginning time and the duration of it. <BR>We made a model rotor supported with two journal bearings to simulate contact vibration, clearance vibration, and oil whip. The vibration phenomena were measured with vertical and horizontal displacement meters at the rotor and vertical and horizontal accelerometers at the rotor bearing and visualized in the time-frequency domain by the wavelet transform. It is found that the dynamic spectra obtained by the wavelet transform of the vertical and horizontal components of displacement and acceleration signals are different for each vibration phenomenon, therefore, this method is able to distinguish each kind of vibration phenomenon. Each vibration phenomenon can be detected and distinguished at the early stage.

ja: 電気学会論文誌B (電力・エネルギー部門誌)


en: Fundamental Study on Locating Partial Discharge Source using VHF-UHF Radio Interferometer System

en: Electrical Engineering in Japan

ja: Electrical Engineering in Japan


ja: VHF-UHF帯電波干渉計システムによる部分放電源特定のための基礎研究

en: The Transactions of The Institute of Electrical Engineers of Japan

ja: 電気学会論文誌


en: Auto Recognition of Handwriting Sequence Diagram using Hyper Cube Multi DSP System

ja: ハイパーキューブ型マルチDSPシステムを用いた手書き電気シーケンス図面の自動認識

en: The Journal of the Digital Signal Processing Applications and Technology of Japan

ja: 高速信号処理応用技術学会誌


en: Identifying Components of Human Movement-Related Cortical Potential using Time-Frequency Analysis based on Wavelet Transform

ja: ヒト運動関連脳電位のウェーブレット変換を用いた時間周波数解析による成分同定


en: Use of Wavelet Transform and Fuzzy System Theory to Distinguish Wear Particles in Lubricating Oil for Bearing Diagnosis


en: Visualization Method of Rotor Vibration using Wavelet Transform for Condition Based Maintenance

ja: ウェーブレット変換を用いた状態基準型保全のための軸振動可視化法

ja: 高速信号処理応用技術学会誌


en: Effect of ELF Electric and Magnetic Fields Exposure in Consideration of the Japanese Technology Standard of the Electric Installation on the EEG Spectra of Human

ja: 日本の電気設備技術基準を考慮したELF電磁界曝露によるヒト脳波スペクトラムへの影響


en: Insulation Diagnosis Method for Generator Winding by Measuring Microwaves Associated with Dielectric Breakdown


en: On-Line Partial Discharge Detection of Turbine Generator Using Gigahertz-Band Spatial Phase Difference Method


en: Detection of Wide-Band E-M Signals Emitted from Partial Discharge Occurring in GIS using Wavelet Transform

en: IEEE Transactions on Power Delivery

ja: IEEE Transactions on Power Delivery


en: Insulation Diagnostic Technique to Assess The Condition of Generator Winding by Measuring Microwave Associated with Dielectric Breakdown

en: IEEE Transactions on Energy Conversion

ja: IEEE Transactions on Energy Conversion


en: DSP Real-time Quench-Detection of Superconducting Coil by Partial Active Power Detecting Method

ja: DSPを用いた部分有効電力検出法による超電導コイルのリアルタイムクエンチ検出

ja: 高速信号処理応用技術学会論文誌


en: Proposal of Partial Active Power Detecting Method for Quench-Detection of Superconducting Coil

ja: 超電導コイルクエンチ検出のための部分有効電力検出法の提案


en: Discrimination of Wear Particle in Lubricating Oil to Diagnose the Bearing using Wavelet Transform and Fuzzy Systems Theory

ja: ウェーブレット解析とファジィ理論を用いた軸受部劣化診断のための潤滑油中摩耗粒子識別


en: On-Line Partal Discharge Detection of Turbine Generator using GHz-Band Spatial Phase Difference Method

ja: GHz帯電磁波空間位相差法を用いた火力タービン発電機の運転中における部分放電検出


en: Insulation Diagnosis Method for the Generator Winding by measuring Microwave Associated with Dielectric Breakdown

ja: 発電機固定子コイルの絶縁破壊現象に伴うGHz帯放射電磁波測定による絶縁劣化診断法

en: The Transactions of The Institute of Electrical Engineers of Japan


en: Location of Partial Discharge by Superimposed Positioning Optimization on the Time Delay of Arrival

ja: 位置標定における重畳最適化法を用いた部分放電源空間標定


en: Use of Spatial Phase Difference Method to Detect microwaves Associated with Stator Coil Partial Discharge in a Generator

en: Electrical Engineering in Japan


en: Wear Particle Detection in the lubricating Oil of the Rotating machine Bearing by Ferrography Analytical Method using Image Processing and Neural Networks

ja: 画像処理技術とニューラルネットワークを適用したフェログラフィー分析法による同期機すべり軸受の潤滑油中摩耗粒子検出


en: Non contact Detection of Electromagnetic Noise Occurrence Due to Partial Discharge by Spatial Phase Difference Method


en: Time-Frequency Analysis of Partial Discharge Phenomena in SF6 gas using Wavelet Transform

ja: SF6ガス中における部分放電現象のウェーブレット変換を用いた時間周波数解析


en: Development of a New System for Detecting Microwave Associated with a Partial Discharge of the Stator Coil in Generator Using Spatial Phase Difference Method

ja: GHz帯電磁波空間位相差法を用いた発電機固定子コイルの非接触部分放電検出システムの開発


en: Wavelet Analysis of Electric Field Changes due to Lightning Discharges

ja: 冬季雷放電に伴う電界変化のウェーブレット解析


en: Non-Contact Detection of Electromagnetic Noise Occurrence due to Partial Discharges by Spatial Phase Difference Method

ja: 電磁波空間位相差法を用いた非接触部分放電検出法


en: Method for Detecting Partial Discharges of Ground Coil from the Vehicle

ja: 車上からの地上コイルの部分放電検出手法

en: RTRI Report

ja: 鉄道総研報告


en: Study on Locating Internal Defect of Ground Coil by Detecting Electromagnetic Waves

ja: 電磁波検出による地上コイル内部欠陥位置標定に関する検討

ja: 鉄道総研報告(鉄道総合技術論文誌)


en: Visualization of Electromagnetic Waves Emitted from Partial Discharge using the Constrained Interpolation Profile (CIP) Method

en: IEEJ Transactions on Electrical and Electronic Engineering (TEEE)


en: Auto Recognition of Handwriting Sequence Diagram using Correlation Method

ja: 相関法を用いた手書き電気シーケンス図面の自動認識

en: Considerable skill is needed to recognize handwriting sequence diagram. In this paper, we proposed auto recognition method of handwriting sequence diagram using correlation method.


en: Analyzing the Distribution of the Magnetic Flux Line Lattice in Superconductors using Image Processing

ja: 画像処理手法による超電導体の磁束分布解析

en: The Transactions of The Institute of Electrical Engineers of Japan


en: Discrimination of Ground Fault Cause on Distribution Line by Wavelet Transform

ja: ウェーブレット変換による配電線地絡故障の原因判別


en: Time Spatial Phase Difference Method by Wavelet Transform to Detect E-M Signals Emitted from PD

ja: ウェーブレット変換を用いた電磁波時空間位相差法による部分放電検出