• Title/Summary/Keyword: electric machine

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Properties of EMNC and EMNSC for Insulation New Material as Apply to High Voltage Heavy Electric Machine (고압중전기기용 절연신소재 EMNC와 EMNSC의 특성연구)

  • Park, Jae-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.10
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    • pp.1454-1460
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    • 2012
  • In order to develop an new electric insulation material for heavy electric equipments, epoxy/micro/nano composite (EMNC) was prepared by mixing micro-silica with nano layered silicate, where the nano layered silicate was synthesized by our electric field dispersion method, EMNSC was prepared by treating the EMNC with a silane coupling agent. Thermal properties such as glass transition temperature (Tg) and thermal expansion coefficient, and DMA characteristics were studied, and mechanicla properties such as tensile and flexural tests were performed. AC electrical insulation strength was also tested. All properties of EMNSC were modified by treating EMNC with silane coupling agent and it was confirmed that our new developed composites could be used in the heavy electric equipments.

Comparative Study of Flux Regulation Methods for Hybrid Permanent Magnet Axial Field Flux-switching Memory Machines

  • Yang, Gongde;Fu, Xinghe;Lin, Mingyao;Li, Nian;Li, Hao
    • Journal of Power Electronics
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    • v.19 no.1
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    • pp.158-167
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    • 2019
  • This research comparatively studies three kinds of flux regulation methods, namely, stored capacitor discharge pulse (SCDP), constant current source pulse (CCSP), and quantitative flux regulation pulse (QFRP), which are used for hybrid permanent magnet (PM) axial field flux-switching memory machines (HPM-AFFSMMs). Through an analysis of the operation principle and the series hybrid PM flux regulation mechanism of the objective machine, the circuit topologies and flux regulation process of these flux regulation methods are addressed in detail. On the basis of a simulation, the flux regulation characteristics of the researched machine during the magnetization and demagnetization processes are comparatively evaluated. Then, machine performance, including back EMF, direct and quadrature axis inductances, and magnetization and demagnetization characteristics, is quantitatively investigated. Results show that the QFRP enables the HPM-AFFSMM to achieve a less harmonic component of back EMF by approximately 7.28% and 7.97% at the magnetization and demagnetization states, respectively, and a more complete magnetization process than the SCDP and CCSP.

A Study for its Characteristics with Electric Variation in an Electrical Discharge Machining (방전가공에서 전기적 변화가 갖는 방전 특성에 관한 연구)

  • 신근하
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.6 no.4
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    • pp.72-79
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    • 1997
  • A study is a experiment which is figure out to optimum discharge cutting condition of the surface roughness, electronic discharging speed and electrode wear ration with Ton , Toff and V(voltage) as an input condition according to the current(Ip) in an electric spark machine : 1) Electrode is utilized Cu and Graphite. 2) Work piece is used the material of carbon steel. The condition of experiment is : 1) Current is varied 0.7(A) to 50(A) and the time of electric discharging to work piece in each time is 30(min) to 60(min). 2) After the upper side of work piece was measured in radius(5$\mu$m) of stylus analyzed the surface roughness to ade the table and graph of Rmax by yielding data. 3) Electro wear ratio is : \circled1Cooper was measured ex-machining and post-machining by the electronic balance. \circled2The ex-machining of graphite measured by it, the post-machining was found the data from volume $\times$specific gravity and analyzed to made its table and graph on ground the data. 4) In order to keep the accuracy of voltage affected to the work piece was equipped with the A.V. R and the memory scope was sticked to the electric spark machine. 5) In order to preserve the precision of current, to get rid of the noise occured by internal resistance of electric spark machine and to force injecting for the discharge fluid , it made the fixed table for a work piece to minimize the work error by means of one's failure during the electric discharging.

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Technical Note : Development of Electric Riding Machine for Cycle Fitting (단신 : 사이클 피팅을 위한 전동 승차 조절기 개발)

  • Bae, Jae-Hyuk;Choi, Jin-Seung;Kang, Dong-Won;Seo, Jeong-Woo;Tack, Gye-Rae
    • Korean Journal of Sport Biomechanics
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    • v.22 no.3
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    • pp.373-378
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    • 2012
  • The purpose of this study was to develop an electric riding machine for cycle fitting to control riding posture easily, to measure frame size quantitatively, and to overcome disadvantages of the traditional systems. The electric riding machine consisted of actuator, load controller, and display & control unit. The actuator unit by BLDC(BrushLess Direct Current) motor drives the saddle height up and down, the crank forward and backward, the handlebar up and down, and the handlebar forward and backward. The load controller unit controls loads by Eddy current controller with electromagnet and aluminum circular plate. The display & control unit consisted of frame size controller and display panel which shows top tube length(485~663mm), head tube length(85~243mm), seat tube length(481~671mm), and seat tube angle($62.7{\sim}76.4^{\circ}$). The range of frame size control for developed electric riding machine did not have difference compared to traditional commercial systems, but quantitative and precise control with 0.1 mm length and $0.1^{\circ}$ angle was possible through digital measurement. Unlike traditional commercial systems, frame size control was possible during riding through motor driven method, thus fitting duration decreased. It is necessary for further improvement to have feedback from users. It is believed that developed electric riding machine can help to develop domestic fitting system.

Maximum Power Recovery of Regenerative Braking in Electric Vehicles Based on Switched Reluctance Drive

  • Namazi, Mohammad Masoud;Saghaiannejad, Seyed Morteza;Rashidi, Amir;Ahn, Jin-Woo
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.800-811
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    • 2018
  • This paper presents a regenerative braking control scheme for Switched Reluctance Machine (SRM) drive in Electric Vehicles (EVs). The main purpose is to maximize the recovered energy during battery charging by taking into account the nonlinear physical characteristics of the Switched Reluctance Machine. The proposed regenerative braking method employs the back-EMF in the generation process as a complicated position-dependent voltage source. The proposed maximum power recovery (MPR) operation of the regenerative braking is first based on the maximization of the extracted power from the machine and then the maximization of the power transferred to the battery. The maximum power extraction (MPE) from SRM is based on maximizing the energy conversion ratio by the calculation of the optimum PWM switching duty cycle, turn-on, and turn-off angles. By using the impedance matching theorem that allows the maximum power transfer (MPT) of the MPE, the proposed MPR is achieved. The parametric averaged value modeling of the machine phase currents in the chopping control mode is used for MPR realization. By following this model, a nonlinear equivalent input resistance is derived for the battery internal resistance matching. The effectiveness of the proposed regenerative braking method is demonstrated through simulation results and experimental implementation.

Driving Characteristics of a 1 Tube 2 Chamber Bent Silkworm Type Dyeing Machine (1 튜브 2 챔버 Bent Silkworm형 염색기의 구동특성)

  • 이춘길;성우경;이광수
    • Textile Coloration and Finishing
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    • v.11 no.2
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    • pp.64-74
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    • 1999
  • The driving characteristics of the 1 tube 2 chamber bent silkworm type dyeing machine are reported. This dyeing machine is a newly developed energy saving machine. In this study, the driving characteristics of the 1 tube 2 chamber bent silkworm type dyeing machine are examined. Specially the relationship between main body pressure and the electric current of the blower motor, the relationship between main body pressure and the air pressure of the blower nozzle, the effect of the air pressure of the blower on the running speed of the fabric, and the effect of main body temperature were discussed experimentally. Through the experimental data, the following results were obtained. 1. Blower motor electric current and blower nozzle air pressure increased as main body pressure increased due to the temperature increase of the main body. 2. The running speed of the fabric increased as blower nozzle air pressure increased. The difference in running speed between winch reel driving and no winch reel driving at a blower frequency of 60Hz was higher than that of 70Hz. 3. The electric current of the blower rioter and blower nozzle air pressure increased rapidly at the initial state. As the experimental time passed, the main body pressure increased slowly. as the main body temperature increased.

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Fuzzy Logic Speed Control Stability Improvement of Lightweight Electric Vehicle Drive

  • Nasri, Abdelfatah;Hazzab, Abdeldjabar;Bousserhane, Ismail.K;Hadjeri, Samir;Sicard, Pierre
    • Journal of Electrical Engineering and Technology
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    • v.5 no.1
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    • pp.129-139
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    • 2010
  • To be satisfied with complex load condition of electric vehicle, fuzzy logic control (FLC) is applied to improve speed response and system robust performance of induction traction machine based on indirect rotor field orientation control. The proposed propulsion system consists of two induction motors (IM) that ensure the drive of the two back driving wheels of lightweight electric vehicle by means the vehicle used for passenger transportation. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling, independently, every driving wheel to turn at different speeds in any curve. Our electric vehicle fuzzy inference system control's simulated in Matlab SIMULINK environment, the results obtained present the efficiency and the robustness of the proposed control with good performances compared with the traditional PI speed control, the FLC induction traction machine presents not only good steady characteristic, but with no overshoot too.

Vibration Characteristics and Its Propagation Path Analysis of an Electric Drill (전동드릴의 진동특성 및 전파경로 해석)

  • 조윤수;김도현;최연선
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.9
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    • pp.422-430
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    • 2001
  • An electric drill is a handy tool used in a machine shop, which consists of motor, gear, bearing, shaft, and case, i.e., a gear driving system. Low level vibration and noise of the electric drill can bring the assurance of the quality and reliability of the machine. The vibration sources of the electric drill should be investigated for the reduction of the vibration and noise of the system. Through the experiments in laboratory and the various signal processing procedure for the measured vibration and sound signals, the characteristics of the vibration of the electric drill are investigated. And its propagation path is sought using partial coherence function.

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Food Powder Classification Using a Portable Visible-Near-Infrared Spectrometer

  • You, Hanjong;Kim, Youngsik;Lee, Jae-Hyung;Jang, Byung-Jun;Choi, Sunwoong
    • Journal of electromagnetic engineering and science
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    • v.17 no.4
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    • pp.186-190
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    • 2017
  • Visible-near-infrared (VIS-NIR) spectroscopy is a fast and non-destructive method for analyzing materials. However, most commercial VIS-NIR spectrometers are inappropriate for use in various locations such as in homes or offices because of their size and cost. In this paper, we classified eight food powders using a portable VIS-NIR spectrometer with a wavelength range of 450-1,000 nm. We developed three machine learning models using the spectral data for the eight food powders. The proposed three machine learning models (random forest, k-nearest neighbors, and support vector machine) achieved an accuracy of 87%, 98%, and 100%, respectively. Our experimental results showed that the support vector machine model is the most suitable for classifying non-linear spectral data. We demonstrated the potential of material analysis using a portable VIS-NIR spectrometer.

Development of Experimental Device for Analysis of Hydraulic Oil Characteristics with Dielectric Constant Sensors (유전상수 센서를 이용한 유압 작동유의 분석을 위한 실험장비 개발)

  • Hong, Sung-Ho
    • Tribology and Lubricants
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    • v.37 no.2
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    • pp.41-47
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    • 2021
  • An experimental device was developed for analysis of hydraulic oil characteristics with dielectric constant sensors. Online analysis is the most effective method of the three methods used for analyzing lubricant oils. This is because it can monitor the machine condition effectively using oil sensors in real time without requiring excellent analysis skill and eliminates human errors. Determining the oil quality usually requires complex laboratory equipment for measuring factors such as density, viscosity, base number, acid number, water content, additive, and wear debris. However, the electric constant is another indicator of oil quality that can be measured on-site. The electric constant is the ratio of the capacitance of a capacitor using that material as a dielectric, compared with a similar capacitor that has a vacuum as its dielectric. The electric constant affects the factors such as the base oil, additive, temperature, electric field frequency, water content, and contaminants. In this study, the tendency of the electric constant is investigated with a variation of temperature, water content, and dust weight. The experimental device can control working temperature and mix the contaminants with oil. A machine condition monitoring program developed to analyze hydraulic oil is described. This program provides graph and digital values with variation of time. Moreover, it includes an alarm system for when the oil condition is bad.