• Journal of Advanced Marine Engineering and Technology
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• 제24권1호
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• pp.75-81
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• 2000

To provide the appropriate direction for development of transient control in a gasoline engine, transient performance analysis and evalution under four accelerating types based on typical driver's acceleration type were implemented by experimental study. In order to evaluate the characteristics of transient performance quanititatively, the concept and method by transient response specifications were introduced. Several performance parameters in terms of engine speed(RPM), manifold absolute pressure(MAP), fuel injection duration($\DeltatI_{nj}$) and air excess ratio($\lambda$) were emasured simultaneously during the four types of the throttle valve opening with the step motor controlled by PC. The result showed that transient response specifications in terms of delay time, rising time and settling time characterized the transient performance for four acceleration types quantitatively. Intensified acceleration type was most economical and linear acceleration type revealed the best emission performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1133-1134
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• 2011

일반적으로 사용하고 있는 유도전동기의 로터는 알루미늄 다이캐스팅 기술을 적용하는 것이 보통이다. 그러나 본 연구에서는 알루미늄에 비해 융점이 높은 동 다이캐스팅 기술을 적용하여 고속 고효율의 공작기계용으로 개발하였다. 30kW급 이상의 전기자동차용과는 달리 공작기계용은 3kW급과 10kW급으로 개발하였으며 슈퍼프리미엄급에 해당되는 성능과 30,000rpm에서 그 성능을 확인하였다.

• 한국유체기계학회 논문집
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• 제14권1호
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• pp.5-10
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• 2011

MTG(Micro turbine generator) operating at 400,000 rpm is under development and the impact test rig to measure the dynamic stiffness and damping coefficient of air foil bearing for high speed rotor is presented in this study. The stiffness and damping coefficient of air foil bearing depending on the rotational speed can be measured easily and effectively by using the simple configuration of impact test rig which is composed of air gun, gap sensors and high speed motor. The estimation results of stiffness and dampling coefficient using least square estimation method is presented as well.

• 한국전기전자재료학회논문지
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• 제21권12호
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• pp.1071-1076
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• 2008

This paper presents the self power generation from vibration using the piezoelectric bimorph actuator. The piezoelectric bimorph actuator was well developed with PZT-PNN-Fe piezoelectric ceramics. As the applied voltage was increased, a linear change of displacement was obtained with a relatively high ratio of 12.53 um/V for the bimorph actuator. Moreover, when the motor's rotational speed was 2000 rpm, the bimorph actuator, which has a resonance frequency of 68 Hz, exhibited the most efficient generation voltage of 10.4 V. This bimorph actuator could make the LED, emitting 60 mW, working successfully. Therefore, it is anticipated that the bimorph actuator will be useful as a power source for the next-generation electronic devices.

• 한국군사과학기술학회지
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• 제12권3호
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• pp.388-395
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• 2009

Surveillance Radar System for naval vessels is a primary core sensor for command and fire control, and provides CFCS(Command and Fire Control System) information for 3-D surveillance and fire control. It's composed of Antenna, Transmitter/Receiver, Signal Processor, and Air drier, which are installed on and under deck. They should be designed and produced in order to endure at any operating circumstances. This paper analyzes load of a driving part for driving the antenna considering factors under external operating circumstances, and proposes a condition of load for maintaining fixed RPM through analyzing internal load of the driving part, and how to reduce the load to meet the condition. This paper is verified through experimental studies.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.37-40
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• 1999

DSP를 이용한 Brushless DC (BLDC) 모터의 초고속 센서리스 제어 기법 및 그 결과가 제시된다. 초고속 BLDC 모터의 센서리스 제어를 위해서 주 제어기로 DSP TMS320C240이 사용되며 제어 기법으로는 Pulse Amplitude Modulation(PAM) 기법이 사용된다. RAM 제어 기법을 사용함으로서 인버터는 six-step 방식으로 구동되며 속도 제어는 인버터 DC 링크 앞 단 쵸퍼의 전압 제어에 의해 이루어진다. 회전자 위치는 역기전력 센싱 방식에 의해 추정되며 TMS320C240의 Event Manager Module에 입력되어 Commutation 위치 및 속도가 계산된다. 계산된 속도는 디지털 PI 제어 알고리즘에 의해 처리되며 제어기의 출력은 쵸퍼의 duty 비를 변화시킨다. 개발된 DSP 제어 보드 및 제어 알고리즘의 성능을 시험하기 위해 실험이 수행되었으며 전체 제어 알고리즘은 DSP TMS320C240의 어셈블리 프로그램에 의해 구현된다. 결과로 최고 속도 50000 [rpm]에서 이상적인 응답 특성을 얻을 수 있었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.427-430
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• 1999

This paper presents a S-FES(Superconducting magnetic bearing Flywheel Energy Storage System) for the purpose of replacing battery used to store the energy. Especially, the design elements of FES, such as the bearing, wheel material, and power converter, etc., is described. The design and manufacturing techniques of the controllable power converter are proposed to generate the sinusoidal output current in the high speed operation and to get the constant DC voltage in the regeneration mode. The cylindrical permanent magnet synchronous motor with halbach array of Nd-Fe-B permanent magnet which is the high coercivity material is used as the driver of FES. The proposed S-FES system shows the stable rotation characteristics at high speed range about 10,000 rpm. To verify the validity of proposed system, the comparative study with the conventional ball bearing system is proceeded and it is well confirmed with the result of the lower friction loss of S-FES system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2380-2382
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• 2004

In this paper, Web server is built up using PXA255, 32bit RISC processor with porting Embedded Linux and GoAhead, HTTP(Hyper Text Transfer Protocol) web server, and the system with can monitor and control the environment and condition for AICC(Automatic Intelligent Cruise Control) is realized. For sending the operation condition and change of vehicle the desired data is derived by interacting ECU(Electric Control Unit) and Embedded system and the rpm of engine is controlled by step motor connected to throttle value.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.129-134
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• 2001

The paper presents the optimal design of a oil-free two-stage compressor, which is driven by 75 kW motor at an operating speed of 39,000 rpm, and the pressure ratio of which is up to 4. First, an attempt is made to obtain the optimal design of a bump bearing which supports a compressor rotor. Second, bump bearings and shaft are considered simultaneously, and the weighted sum of rotor weight and frictional torque is minimized. Finally, the optimal geometry of compressor wheel is considered. The mean efficiency and the - minimum efficiency are maximized respectively. The results presented in this paper provide important design information necessary to reduce the energy loss.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.917-922
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• 2003

In this paper, a high speed rotating arc sensor for automatic fillet welding is introduced. In order to track the welding seam, The high speed rotating arc sensor is used. The welding tip of a high speed rotating arc sensor rotates about 3000 rpm using DC motor. The rotating torch is driven by gear between welding torch body and wire guide. The welding current is measured by using the current sensor and rot at ing position sensor. To realize the welding seam tracking algorithm with accuracy, a software filter algorithm using the moving average method is applied to the measured welding current in the microprocessor. The welding mobile robot with two wheels and two sliders is developed for fillet welding. The welding mobile robot can control its traveling direction and turn itself around the corner. The effectiveness is proven through the experimental results conducted with varied fillet tracking patterns.