• Title/Summary/Keyword: Economical Validity

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Development of IGBT Stacks for Cost Reduction (원가절감형 IGBT스택 개발)

  • Hong S.C;Kang K.W.;Jung W.C.;Hwang Y.H.
    • Proceedings of the KIPE Conference
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    • 2003.07a
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    • pp.128-132
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    • 2003
  • This paper deals with the development of IGBT stacks for cost reduction. One stack is consist of 4 IGBTS in parallel. In the high- and mid-power converters, IGBT stacks are more suitable than single IGBTS in the aspects of total cost of semiconductor devices, time for purchasing, maintenance, radiation of heat, size of surge absorber and harmonic filter, frequency characteristics, and etc.. Problems accompanied by parallel construction are studied and solved. Economical efficiency is discussed and field tests with 100kVA UPS are tarried out to verify the validity of the developed IGBT stacks.

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The Functional Analysis of Blending Brake Control for Stanrard EMU (표준전동차 혼합제동 기능분석 연구)

  • Lee, Woo-Dong
    • Proceedings of the KIEE Conference
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    • 2008.10b
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    • pp.466-467
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    • 2008
  • There are many new technologies for EMU to secure the facilities' safety/validity and maintenance/economical efficiency and technologic competitiveness. For example, now the EMU is using the blending brake technology with electric brake and pneumatic brake and carrying the various performances such as jerk limitation, variable load and blending brake to stop the motor car safely and efficiently. The blending brake takes important parts in braking the cars and It is used in many fields of urban transit. There were many limitations to carry the performances and certificate whether the performances are acceptable in the system or not, because at that time they didn't take the whole prelieminarly inspection. Now we start applying such new methods, taking the whole inspection prior to the installation by analyzing systems requirements and introducing various system engineering design tools. In this paper, we suggest how to reduce the errors by prelieminarly inspection for the brake facilities using the tools and inspect the needs to analyze the brake facilities' performances.

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A Study on the Energy Storage Mass of Urban Transit System (도시철도시스템의 에너지 저장방식에 관한 연구)

  • Lee, Han-Min;Kim, Gil-Dong;Lee, Chang-Mu
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.831-835
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    • 2007
  • Energy Saving is one of worldwide emerging issues. These days, applicable techniques of railway vehicle's regenerative energy are investigating in worldwide railway industries. Energy saving methods are "Downsizing energy loss" and "Re-utilizing kinetic energy". Useful plans for Downsizing energy loss are "adjusting operation table" and "optimizing running pattern". Furthermore, regenerative energy that is produced with decreasing speed and stoping, is an important element with reducing vehicle's weight, raising equipment 's efficiency, decreasing running resistance and re-configurating running pattern. Sustainable energy storage mass : Flywheel, EDLC(electrical double layer capacitor) and Secondary battery are applied in overseas, but these cases are not reported within the country. This research is reported for problems and economical validity that comes from by installing sustainable regenerative energy storage system in korean railway industries.

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Multi-level PWM Inverter for 3-Phase High Voltage Power On-Grid (3상 고압 전력연계를 위한 다중레벨 인버터)

  • Ahn, Hyun-Jin;Lee, Hwa-Chun;Song, Sung-Gun;Lee, Sang-Hun;Park, Sung-Jun;Kim, Kwang-Heon;Lim, Young-Cheol
    • Proceedings of the KIPE Conference
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    • 2008.06a
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    • pp.562-564
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    • 2008
  • This paper deals with the three phase high voltage power-grid connection topology using multi-level inverter. Due to the multi-level inverter, these are improved effect of fluctuating voltage, problem of EMC and switching loss using suitable switching patterns of device, above all thing, it is easy to realize the system because of using lower voltage rating switch. This topology can be applicable to power-grid connection of wind system, there is a good point about economical efficiency. The simulation results are presented to verify the validity of the proposed topology.

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Reduction of Minimum Switching Duration in the Measurement of Three Phase Current with DC-Link Current Sensor (DC링크 전류센서를 이용한 삼상전류 측정 방식에서 최소 스위칭 시간의 단축)

  • 김경서
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.12
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    • pp.649-654
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    • 2003
  • The simplest method for measuring output currents of the three phase inverters is to measure them with three current sensors such as hall sensors. This method requires at least two current sensors, and these types of sensors are somewhat expensive. More economical method is measuring DC link current with a simple shunt resistor, then, reconstructing output current using the DC link current value and the switching status. However, in low speed region, the measurement becomes difficult and even impossible due to the requirement of minimum switching duration for A/D conversion. These problems can be overcome by limitation of switching duration. Limitation of switching, however, causes voltage and current distortion. Owing to compensation, distortion can be effectively suppressed. However these increase acoustic noise due to increment of current ripple. In this paper, a current measurement method is proposed, which can reduce minimum switching duration resulting in reduction of acoustic noise. The validity of proposed method is confirmed through experiment.

Load Forecasting using Hierarchical Clustering Method for Building (계층적 군집분석방법을 활용한 건물 부하의 전력수요예측)

  • Hwang, Hye-Mi;Lee, Sung-Hee;Park, Jong-Bae;Park, Yong-Gi;Son, Sung-Yong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.1
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    • pp.41-47
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    • 2015
  • In recent years, energy supply cases to take advantage of EMS(Energy Management System) are increasing according to high interest of energy efficiency. The important factor for essential and economical EMS operation is the supply and demand plan the hourly power demand of building load using the hierarchical clustering method of variety statistical techniques, and use the real historical data of target load. Also the estimated results of study are obtained the reliability through separate tests of validity.

Development of 4-axis CNC Controller for Removing Trajectory Error (궤적 오차를 제거한 4축 CNC 제어기의 개발)

  • 이치환
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.406-409
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    • 1997
  • An economical 4-axis CNC controller employing step motors is designed and implemented in this paper. By using the inherent ability of holding position of the motor, the CNC controller uses open-loop control for removing trajectory error and for a simple hardware. Each drive of axis has an 8-bit microprocessor 89C52 and a PC controls the axes and pendant by means of RS232C serial communication. Backlash is also compensated at the axis controller. While compensating the backlash, the feed rate becomes zero in order to minimize trajectory error. The trajectories of 16ms interval are computed on PC and are sent to motor drives. In the drives, the trajectories are linearly interpolated for 2ms interval. The developed CNC does not require add-on specific motion card on PC. From the experimental results, the validity of the CNC controller based on step motor is proved.

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The Functional Analysis for Brake Operating Unit of EMU (전동차 제동장치 기능분석 연구)

  • Lee, Woo-Dong
    • Proceedings of the KIEE Conference
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    • 2008.10c
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    • pp.211-212
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    • 2008
  • There are many new technologies for EMU to secure the facilities' safety/validity and maintenance/economical efficiency and technologic competitiveness. For example, now the EMU is using the blending brake technology with electric brake and pneumatic brake and carrying the various performances such as jerk limitation, variable load and blending brake to stop the motor car safely and efficiently. Now we start applying such new methods, taking the whole inspection prior to the installation by analyzing systems' requirements and introducing various system engineering design tools. In this paper, we suggest how to reduce the errors by prelieminarly inspection for the brake facilities using the tools and inspect the needs to analyze the brake facilities' performances.

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A study on development of plastic intake manifold module (Plastic 흡기 매니폴드 모듈 개발에 관한 연구)

  • Lee, Jeong-Kyun;Kim, Young-Bok;Joo, Kyung-Jei
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.833-838
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    • 2011
  • Future powertrain technologies will be developed focused on applications of eco-friendly technology for internal combustion engine, electric vehicle and Fuel Cell Electric Vehicle. But it is expected that these cutting edge technologies will not be applied immediately due to lack of infrastructure, technical and economical reasons. Therefore, numerous developments of internal combustion engine will be carried out for the time being. There have been many turbo engine developments undergoing to maximize the engine performance using turbo charger system in accordance with global trend-green technology and downsizing of engine which coincides with HMC's future development strategy. This study reviews the development process and result of plastic intake manifold module which is firstly developed for turbo engine. CAE simulation and experiments were implanted to evaluate design validity.

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Structural Design of Double Hull Bulk Carrier (이중선체 벌크 캐리어의 선체 구조설계)

  • Cho, Kyu-nam;Song, Ha-Cheol;Choun, Byoung-hee;Kim, Min-Won;Kim, Min
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.303-310
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    • 2002
  • After many casualties with conventional bulk carriers in recent years, double hull bulk carrier was proposed to enhance the structural safety of side shell and transverse bulkhead. In this paper, two alternative structural designs of double hull bulk carrier were executed based on the Lloyd's rule, and the results were examined in comparison with the existing single hull bulk carrier in the viewpoints of the increase of weight and construction cost. The relative construction concept was used to certify the economical validity of double hull bulk carrier.

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