• Title/Summary/Keyword: 저속전기차

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Sensorless control of the Next Generation High Speed Drive System in low speed region (차세대 고속전철 저속영역에서의 센서리스 제어)

  • Jin, Kang-Hwan;Suh, Yong-Hun;Lee, Sang-Hyun;Kim, Yoon-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.12
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    • pp.82-87
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    • 2011
  • In this paper, a sensorless speed control system is designed for the next generation high speed railway at zero and low speed region. The applied vector control scheme is a maximum torque per ampere(MTPA) method to utilize reluctance torque of IPMSM. The designed sensorless control scheme is a rotating high frequency voltage signal injection method. To verify the designed system, a simulator for the vector controller and sensorless controller is implemented using Matlab/simulink.

Speed Sensorless Control of Induction Motors in the Very Low Speed Region Considering the Secondary Resistance Identification using Flux Signal (자속정보를 이용한 2차저항 동정기능을 갖는 유도전동기의 저속영역 속도센서리스 제어)

  • Lee, Z.G.;Jeong, S.K.
    • Proceedings of the KIEE Conference
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    • 2001.04a
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    • pp.308-310
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    • 2001
  • This paper investigates a novel speed sensorless control method of I.M considering the secondary resistance identification based on the transientless torque control technique. Especially, this paper aimed at the identification of the secondary resistance simultaneously with speed estimation superposing of sinusoidal flux wave to a constant flux value. Furthermore, the secondary flux with some frequency is controlled independently on torque control. The proposed speed estimation method is derived from a motor circuit equation theoretically and also it can be conducted easily by detecting primary motor currents and primary voltage commands at every sampling time. Some numerical simulations with the assumption of using a pulse width modulation(PWM) voltage source inverter are performed to verify the proposed method.

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Speed Sensorless Control of Induction Motors in the Very Low Speed Region Considering the Secondary Resistance Identification (2차 저항 동정을 고려한 유도전동기의 저속영역 속도센서리스 제어)

  • Hwang, D.I.;Jeong, S.K.
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1042-1045
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    • 2000
  • Speed control without speed sensor is expected strongly to progress reliability, simplicity and cost performance of I.M and to expand its application part. This paper investigates a novel speed estimation method of I.M considering the secondary resistance identification based on the transientless torque control technique. Especially, this paper aimed at the identification of the secondary resistance simultaneously with speed estimation. For this, the secondary flux with some frequency is controlled independently on torque. The proposed speed estimation method is derived from a motor circuit equation theoretically and also it can be conducted easily by detecting primary motor currents and primary voltage commands at every sampling time. Some numerical simulations with the assumption of using a pulse width modulation(PWM) voltage source inverter and experimental results are performed to verify the proposed method.

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Flight Test of Hybrid Propulsion System for Electrically Powered UAV (전기동력 무인기용 하이브리드 추진시스템 비행시험)

  • Park, Poomin;Kim, Keunbae;Cha, Bongjun
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.4
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    • pp.49-55
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    • 2013
  • This paper deals with the flight test of propulsion system of middle size electrically powered UAV (EAV2, Electric Aerial Vehicle 2) which is under development in KARI. EAV2 is low speed endurance type UAV whose wing span is 6.9 m, and weight is 18 kg. The UAV has flown for 22 hours in June of 2012. The flight test result showed that the propulsion system worked well suppling power for any circumstances during the test flight. Each power source worked according to the design purpose.

Case Studies of Geophysical Mapping of Hazard and Contaminated Zones in Abandoned Mine Lands (폐광 부지의 재해 및 오염대 조사관련 물리탐사자료의 고찰)

  • Sim, Min-Sub;Ju, Hyeon-Tae;Kim, Kwan-Soo;Kim, Ji-Soo
    • The Journal of Engineering Geology
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    • v.24 no.4
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    • pp.525-534
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    • 2014
  • Environmental problems typically occurring in abandoned mine lands (AML) include: contaminated and acidic surface water and groundwater; stockpiled waste rock and mill tailings; and ground subsidences due to mining operations. This study examines the effectiveness of various geophysical techniques for mapping potential hazard and contaminated zones. Four AML sites with sedimentation contamination problems, acid mine drainage (AMD) channels, ground subsidence, manmade liner leakage, and buried mine tailings, were selected to examine the applicability of various geophysical methods to the identification of the different types of mine hazards. Geophysical results were correlated to borehole data (core samples, well logs, tomographic profiles, etc.) and water sample data (pH, electrical conductivity (EC), and heavy metal contents). Zones of low electrical resistivity (ER) corresponded to areas contaminated by heavy metals, especially contamination by Cu, Pb, and Zn. The main pathways of AMD leachate were successfully mapped using ER methods (low anomaly peaks), self-potential (SP) curves (negative peaks), and ground penetrating radar (GPR) at shallow penetration depths. Mine cavities were well located based on composite interpretations of ER, seismic tomography, and well-log records; mine cavity locations were also observed in drill core data and using borehole image processing systems (BIPS). Damaged zones in buried manmade liners (used to block descending leachate) were precisely detected by ER mapping, and buried rock waste and tailings piles were characterized by low-velocity zones in seismic refraction data and high-resistivity zones in the ER data.

Effect of Major Factors on the Spray Characteristics of Ultrasonic Atomizing Nozzle (초음파 미립화 노즐의 분무 특성에 미치는 주요 인자의 영향)

  • Jeong, Seon Yong;Lee, Kye Bock
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.6
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    • pp.1-7
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    • 2017
  • The atomization of a liquid into multiple droplets has many important industrial applications, including the atomization of fuels in combustion processes and coating of surfaces and particles. Ultrasonic atomizing nozzle has a transducer that receives electrical input in the form of a high frequency signal from a power generator and converts that into mechanical energy at the same frequency. Liquid is atomized into a fine mist spray using high frequency sound vibrations. In coating applications, the unpressurized, low-velocity spray reduces the amount of overspray significantly because the droplets tend to settle on the substrate, rather than bouncing off it. The spray can be controlled and shaped precisely by entraining the slow-moving spray in an ancillary air stream using specialized types of spray-shaping equipment. The desired patterns of spray can be obtained using an air stream. To simulate the water mist behavior of an ultrasonic atomizing nozzle using an air stream, the Lagrangian dispersed phase model was employed using the commercial code FLUENT. The effects of the nozzle contraction shape, water droplet size and the pneumatic pressure drop on the spray characteristics were investigated to obtain the optimal condition for coating applications.

Fabrication Method of High-density and High-uniformity Solder Bump without Copper Cross-contamination in Si-LSI Laboratory (실리콘 실험실에 구리 오염을 방지 할 수 있는 고밀도/고균일의 Solder Bump 형성방법)

  • 김성진;주철원;박성수;백규하;이희태;송민규
    • Journal of the Microelectronics and Packaging Society
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    • v.7 no.4
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    • pp.23-29
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    • 2000
  • We demonstrate the fabrication method of high-density and high-quality solder bump solving a copper (Cu) cross-contamination in Si-LSI laboratory. The Cu cross-contamination is solved by separating solder-bump process by two steps. Former is via-formation process excluding Cu/Ti under ball metallurgy (UBM) layer sputtering in Si-LSI laboratory. Latter is electroplating process including Ti-adhesion and Cu-seed layers sputtering out of Si-LSI laboratory. Thick photoresist (PR) is achieved by a multiple coating method. After TiW/Al-electrode sputtering for electroplating and via formation in Si-LSI laboratory, Cu/Ti UBM layer is sputtered on sample. The Cu-seed layer on the PR is etched during Cu-electroplating with low-electroplating rate due to a difference in resistance of UBM layer between via bottom and PR. Therefore Cu-buffer layer can be electroplated selectively at the via bottom. After etching the Ti-adhesion layer on the PR, Sn/Pb solder layer with a composition of 60/40 is electroplated using a tin-lead electroplating bath with a metal stoichiometry of 60/40 (weight percent ratio). Scanning electron microscope image shows that the fabricated solder bump is high-uniformity and high-quality as well as symmetric mushroom shape. The solder bumps with even 40/60 $\mu\textrm{m}$ in diameter/pitch do not touch during electroplating and reflow procedures. The solder-bump process of high-uniformity and high-density with the Cu cross-contamination free in Si-LSI laboratory will be effective for electronic microwave application.

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Lithium Battery Anode Properties of Ball-Milled Graphite-Silicon Composites (볼밀링법으로 제조된 흑연-실리콘 복합체의 리튬전지 음전극 특성)

  • Kang, Kun-Young;Shin, Dong Ok;Lee, Young-Gi;Kim, Kwang Man
    • Korean Chemical Engineering Research
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    • v.51 no.4
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    • pp.411-417
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    • 2013
  • To use as an anode material of lithium secondary battery, graphite-silicon composite powders are prepared by ball-milling with silicon nanoparticles (average diameter 100 nm, 0~50 wt%) and graphite powder (average diameter $15{\mu}m$) and their electrochemical properties are examined. As the silicon content increases, the graphite becomes smaller by the ball-milling and amorphous phase appears whereas the silicon do not suffer the change of nanocrystalline phases and embeds within the amorphous phase of graphite. Cyclic voltammetry at low scan rate reveals that typical oxidation peaks of graphite and silicon appear at 0.2~0.35 and 0.55~0.6 V, respectively, with higher reversibility for repeated cycles. In contrast, the high-scan-rate redox behavior is very irreversible for repeated cycles. High irreversible capacity is exhibited in the initial charging-discharging cycles, but it diminishes as the cycle number increases. The saturated discharge capacity achieves about 485 mAh $g^{-1}$ at 50th cycle for the composite of Si 20 wt%. This is due to the formation of amorphous graphite morphology by the adequate composition (C:Si=8:2 w/w), which efficiently buffers the volume change during alloying/dealloying between silicon and lithium.

Case study on the lake-land combined seismic survey for underground LPG storage construction (LPG 지하저장기지 건설을 위한 수륙혼합 탄성파탐사 사례)

  • Cha Seong-Soo;Park Keun-Pil;Lee Ho-Young;Lee Hee-Il;Kim Ho-Young
    • 한국지구물리탐사학회:학술대회논문집
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    • 2002.09a
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    • pp.101-125
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    • 2002
  • A lake seismic survey was carried out to investigate possible geohazards for construction of the underground LPG storage at Namyang Lake. The proposed survey site has a land-lake combined geography and furthermore water depth of the lake is shallow. Therefore, various seismic methods such as marine single channel high resolution seismic reflection survey, sonobuoy refraction survey, land refraction survey and land-lake combined refraction survey were applied. Total survey amounts are 34 line-km of high resolution lake seismic survey, 14 lines of sonobuoy refraction survey, 890 m of land refraction survey and 8 lines of land-lake combined refraction survey. During the reflection survey, there were severe water reverberations from the lake bottom obscured subsurface profiling. These strong multiple events appeared in most of the survey area except the northern and southern area near the embankment where seems to be accumulated mainly mud dominated depositions. The sonobuoy refraction profiles also showed the same Phenomena as those of reflection survey. Meanwhile the results of the land-lake combined refraction survey showed relatively better qualities. However, the land refraction survey did not so due to low velocity soil layer and electrical noise. Summarized results from the lake seismic survey are that acoustic basement with relatively flat pattern appeared 30m below water level and showed three types of bedrock such as fresh, moderately weathered and weathered type. According to the results of the combined refraction survey, a velocity distribution pattern of the lake bottom shows three types of seismic velocity zone such as >4.5 km/s, 4.5-4.0km/s and <4.0km/s. The major fault lineament in the area showed NW-SE trend which was different from the Landsat image interpretation. A drilling was confirmed estimated faults by seismic survey.

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