• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.527-533
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• 1998

An optimized PWM switching strategy for an induction motor voltage control is developed and demonstrated. Space vector modulation in voltage source inverter offers improved DC-bus utilization and reduced commutation losses, and has been therefor recognizedas the perfered PWM method, especially in the case of digital implementation. Three-phase invertor voltage control by space vector modulation consists of switching between the two active and one zero voltage vector by using the proposed optimal PWM algorithm. The prefered switching sequence is defined as a function of the modulation index and period of a carrier wave. The sequence is selected by suing the inverter switching losses and the current ripple as the criteria. For low and medium power application, the experimental results indicate that good dynamic response and reduced harmonic distortion can be achieved by increasing switching frequency.

• Journal of Magnetics
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• 제18권3호
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• pp.255-259
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• 2013

In this paper a new coupling method for efficient and simple analysis of single phase induction motor is presented. The circuit representation of both the stator winding and each conducting rotor loop (composed of rotor bar and end ring segment) is used in conjunction with the distribution of magnetic flux linkage instead of inductance matrix. The flux linkage is calculated using air-gap flux density distributions driven by unit currents in the stator windings and rotor bars. The field distribution of one turn of a coil is calculated by FEM and the result is used to calculate total flux linkage by employing a coordinate transformation. The numerical results give good agreement with prior literature. The method is particularly effective in analyzing the effect of the number of rotor bars.

• 제어로봇시스템학회논문지
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• 제3권1호
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• pp.40-45
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• 1997

A robust disturbance rejection controller for the hovering motion of underwater vehicles in near the surface of sea is presented. The suggested controller consists of two control parts, the one is disturbance observer for taking into account the effects of sea wave and missile-launching forces, and the other is sliding mode controller for the robust stability of underwater vehicles with model uncertainties and nonlinearities. It is shown that the sliding mode control system with disturbance observer is more effective compared with the sliding mode control system, especially in case that large sea wave force is affected.

• 대한조선학회지
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• 제10권2호
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• pp.29-37
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• 1973

Since 1967 the Towing Tank of Inha University has been planed constracted and was completed 1971. The size of the tank is 79m length, 5m width 3m depth. At one end of the tank, 18kw wave maker is installed which can produce regular and irregular waves, max. 6m length 40cm height. The towing carriage is driven by four 2.2kw motor and reuglated by electronic speed regulator, and it's max. towing speed is 2.5m/sec, resistance dynamometer and some other instruments including clamp, towing guide etc. are designed and made by us. Here under, the authors wish to give some details of facilities and calibrated performance of the towing carriage, wave maker and resistance measuring system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.135-138
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• 2001

This paper presents micro step driving method using VHDL(Very high speed integrated circuit Hardware Description Language) which can configure CPLD(Complex Programmable Logic Device). Using VHDL which can do abstractive programming is similar to high level language. The whole block divided into five parts with freq. divide part, saw-tooth wave generation part, sine-cosine wave generation part, comparative part, out part. In the result of this study, peripheral circuits are to be simple and using LPM(Library of Parameterized Modules) is more easily to configure circuit. It is easy to verify and implement by using VHDL. To subdivide one natural step, we confirm that using micro step driver is expected that the rotor motion is stepless very smooth.

• 한국정보통신학회논문지
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• 제13권5호
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• pp.922-930
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• 2009

유도 전동기를 전압 제어하기 위한 최적 PWM 스위칭 방법을 제시하려한다. 전압 인버터의 공간 벡터 변조 방식은 DC-버스 이용을 향상시키고 정류 손실을 감소시키기 때문에 디지털 구현의 경우 특히 선호하는 PWM 방법이다. 유도 전동기 전압 제어를 위한 최적 PWM 스위칭 방법은 제시한 최적 PWM 알고리즘을 사용하여 두 개의 활성 전압 벡터(active voltage vector)와 하나의 영 전압 벡터(zero voltage vector)로 구성하였다. 선택된 스위칭 순차 열은 변조 지수(modulation index)와 운송파(carrier wave) 주기의 함수로 정의 된다. 순차 열은 인버터 스위칭 손실과 전류 리플 값을 기준으로 사용하여 선택된다. 실험 결과 중 저 전력용으로 사용할 경우 스위칭 주파수를 증가시킴에 따라 고조파 왜곡이 감소하고 동특성이 좋아짐을 확인할 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2274-2277
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• 2003

A cylindrical permanent magnet inside the four-phase permanent magnet (PM) stepping motor is employed as the rotor. The stator has four teeth around, which its coils are wound. The mode of excitation can be classified into 3 modes: single-phase excitation, two-phase excitation and ministep excitation. The ministep drive is a method to subdivide one step into several small steps by means of electronics. The paper presents the programmable ministep technique drive. This technique decodes the results obtained from the counter to locate the data in Read Only Memory (ROM). The Sinusoidal Pulse Width Modulation (SPWM) is transformed to binary file and saved to the ROM. The experiment is performed with the four-phase PM stepping motor and drives from a two-phase programmable sinusoidal ministep signal, instead of square wave. The results show that the performances of the proposed programmable ministep technique drive have high efficiency, smooth step motion, and high speed response. Moreover, the resolution of sinusoidal ministep signal can be controlled by the input frequency (f command).

• 전력전자학회논문지
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• 제9권1호
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• pp.88-95
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• 2004

스테핑 모터의 위치 분해능을 향상하고 기계적 공진을 방지하기 위한 제어방법으로 마이크로 스텝 구동방식이 많이 이용되고 있다. 이론적인 마이크로 스텝 구동방식은 정현파를 기준신호로 사용하며, 마이크로프로세서 및 ROM을 사용함으로써 구동회로가 복잡하고, 가격이 증가하는 단점을 가지게 된다. 본 연구에서는 기준신호를 사다리꼴 파형으로 사용함으로써 제어회로를 간략화하고 저가의 제어장치로 마이크로 스테핑 구동방식을 구현하는 방법을 제안하고 있다. 제안한 방식을 검증하기 위하여 저가의 CPLD(EPM9320RC208-15)를 이용하여 구동장치를 구성하였으며, 실험을 통하여 기존의 방식과 성능을 비교하였다. 또한 CPLD 내부에 고속검출회로를 구현하여 고속 구동시 모터의 탈조를 방지하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.451-454
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• 2002

In this paper, studied on the one-chip design of low cost for the micro-stepping drive having 5-phase Pentagon Type winding. Micro-stepping method in order to eliminate effectively the resonant phenomena and to Increase the positional resolution. This paper proposed trapezoidal current wave- form for current control and provided design- method by using only one-chip of low cost. Therefore the drive will be simple and small size. Also the drive will have a lot of advantage at commercial business. Finally the above study has been implemented on the VHDL. Simulation has been performed to verify the PWM for micro-stepping drive.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.53-56
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• 2001

This paper has been developed a millimeter-wave radar to prevent car collision. This system needs to progress the problem as follows; (1) Increase of traffic accidents causing damage and injuries due to the increased number of motor vehicles and long distance driving, (2) Need for a device to help drivers who are in trouble due to bad weather conditions. (3) Need for a millimeter-wave radar as obstacles which need to be detected are small. This system is composited with some major technologies, Narrow beams to recognize obstacles or other objects, One-side circuit technology to prevent interference between electric waves, and Parts designed for radar products which are able to transmit millimeter - waves. The system has a various a application Field, Car distance auto-control system, prevent bump collision due to unexpected stoppage of the front car or careless driving, obstacle warning system, Car following system, and industrial and military purposes system. We have a looking forward to propose to develop field tests under various road conditions and hybrid car sensor by combining with other sensors