• 전기학회논문지
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• 제66권12호
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• pp.1721-1724
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• 2017

This paper presents a numerical optimization technique to reduce input current and torque ripple of the low voltage BLDC motor using core, coil and switching angle optimization. The optimization technique is employed using the generalized response surface method(RSM) and sampling minimization technique with FEM. A 50W 24V BLDC motor is used to verify the proposed algorithm. As optimizing results, the input current is reduced from 2.46 to 2.11[A], and the input power is reduced from 59 [W] to 51 [W] at the speed of 1000 [rpm]. Also, applied the same optimization algorithm, the torque ripple is reduced about 7.4 %. It is confirmed that the proposed technique is a reasonably useful tool to reduce the consuming current and torque ripple of the low voltage BLDC motor for a compact and efficient design.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.318-319
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• 2007

In this study, novel structured thin ultrasonic rotary motor has been proposed. Ultrasonic motors are based on an elliptical motion on the surface of elastic body. ATILA ver. 5.2.4 was used for optimizing stator. The motor was fabricated by using designed stator. And characteristics of the motor were compared with simulated results. When the motor was fabricated with these results, 935[rpm] speed was obtain by input voltage of 25[Vrms] at 93.5[khz].

• 해양환경안전학회지
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• 제23권6호
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• pp.754-758
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• 2017

본 논문에서는 선박의 안전운항을 위하여 안개 발생 시 엔진을 자동으로 제어하여 피해를 최소화하거나 회피할 수 있도록 자동 제어 시스템을 설계 및 제작 하였다. 제작된 동력 자동제어시스템은 ATmega128과 RPM감지회로를 사용하여 안개발생부에서 인위적으로 안개를 발생시켜 RPM의 변화량을 측정하였다. 이를 위하여 전체구성도를 작성하였으며 홀센서가 있는 모터를 사용하여 PWM 제어를 하도록 ATmega128에 Source code를 적용시켰다. 추후, 제작된 동력 자동제어장치를 통하여 실제 선박에서의 실험 및 안전성평가를 마련할 계획이다.

• 한국초전도ㆍ저온공학회논문지
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• 제6권3호
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• pp.33-37
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• 2004

This paper presents the construction and test results of an HTS induction motor. End rings and short bars were made of HTS tapes, To increase the efficiency and starting torque, HTS tapes can be used as the rotor bars. Because large current is induced in the rotor circuit, HTS tapes quench and high starting torque can be obtained. As the speed of rotor builds up. HTS tapes which are used as short bars become superconducting state again. After the HTS tapes recover from quench, resistance of the rotor circuit is nearly zero. In that case, power loss in rotor circuit is eliminated. Stator of the conventional induction motor was used as the stator of the HTS motor. Rated capacity of the conventional motor was 0.75 kW. Performances of the HTS induction motor were compared with those of the conventional motor with same volume and specification. Test result showed that the speeds of the HTS induction motor were the same with synchronous speed up to 2.6 Nm and 1.788 rpm at 9.7 Nm. It guarantees the high efficiency of the HTS motor. Starting torque of the HTS motor was more than twice of the conventional motor.

• 대한기계학회논문집A
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• 제37권1호
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• pp.105-111
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• 2013

주축은 공작기계의 핵심요소로서 주축의 정 동적 특성은 공작물의 가공정밀도에 직접적으로 영향을 미친다. 주축의 특성은 축 크기, 베어링 간격, 내장모터의 위치 등에 의해 결정된다. 그러므로 축 크기, 베어링 간격, 모터위치의 선정은 주축 특성을 개선하는데 중요한 요소라 할 수 있다. 본 논문은 40,000rpm 고속주축의 정 동적 해석과 최적 설계에 관한 연구로, 유한요소해석과 최적화를 위한 통계분석을 하였다. 이를 위하여 반응표면법을 사용하여 목적함수와 설계변수를 최적화하였다. 최적화 대상은 주축의 고유진동수의 최대화와 변위의 최소화이다. 설계변수는 축길이, 축직경, 베어링 간격, 모터위치로 선정했다. 최적설계를 통해 도출된 설계안으로 초기모델보다 개선된 결과를 얻을 수 있었고, 본 연구의 결과를 주축 설계에 적용하면 주축의 정 동적 특성 개선에 도움이 될 것으로 기대된다.

• 한국정밀공학회지
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• 제26권5호
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• pp.79-86
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• 2009

Recently PMSM(Permanent magnet synchronous motor) are used for the various direct drive applications such as index table, telescope system and so on. Because the position/speed control performance of direct drive PMSM is directly affected by the torque ripple, there are lots of studies to reduce the cogging torque in the motor design stage. In order to verify the motor design, the reliable cogging torque measurement system is essentially required. The measured motor must be rotated in the constant speed under 1deg/sec so that the cogging torque profile is measured correctly. In this study, the cogging torque measurement system which uses the direct drive PMSM and the speed controller to rotate the measured motor in 0.1rpm(0.6deg/sec) has been developed. Simulink/xPC target was used for the controller and data acquisition system. Based on PI controller, DOB and AFC have been applied to eliminate the low frequency disturbances and the periodic speed ripple. The experimental results show the good performance of the speed regulation for the reference speed 0.1rpm and the reliable profile of the measured cogging torque by the developed speed controller.

• 한국진공학회지
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• 제6권S1호
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• pp.89-95
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• 1997

A new type of piexoelectric membrane traveling wave motor has been designed and forbricated. The small motor is composed by the stator which is the combination of annular/circular membrane and metal elastic base using as the common electrode at some time and the rotor which is placed on the metal elastic body. Thus the motor structure is simple and easy to fabricate. The material of a piezoelectric membrane is fabricated by sol-gel method or wear-down method. A piezoelectric traveling wave motor has been fabricated with the stator diameter 8mm The total thickness of the stator is 350$\mu$m. Under the alternative excitation voltage 10-12V the revolving speed of the rotor is more than 100RPM.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.699-702
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• 1992

A miniature size electrostatic induction motor have been constructed and studied by applying a three phase ac power source with a maximum voltage of 5 KV and a variable frequency ranged 0.0 - 150 Hz. A maximum no load speed of the motor tested was about 7600 RPM at the applied voltage of 4330 volt and the frequency of 130 Hz for the case of the rotor surface material of polyprophylene sheet screen-printed $TiO_2$ powder on it. It is found that there are 3 different regions of the motor operation, a rotor stop region, a stable operation region and a high speed abnormal region. And it is also found that the motor speed is influenced greatly by the charge relaxation time constant of the rotor surface materials, which however was changed by the means of vapour-deposited Ti or Ni and screen-printed $TiO_2$ powder on the surface of the rotor material, polyprophylene.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.841-845
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• 1995

In this study, a motor-integrated high-speed spindle system with .psi. 65mm*25,000rpm is developed by introducing the oil-jet lubrication method,ceramic angular contact ball bearing, a built-in motor and so on. And oil-jet lubrication experiments for evaluating the system performance are performed under various operation conditions. Especially, in order to establish the oil-jet lubrication conditions related to the development of a high-speed spindle system, the effects of oil supply rate and rotational spindle speed are investigated on the temperature rise, temperature distribution,motor current and so on.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.749-751
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• 1998

In this study, the wind-mill type ultrasonic motor was fabricated, and then revolution and temperature characteristics of the ultrasonic motor were measured. Brass metal was pressed with umbrella-type using metal mold, then slot of 4 kind was processed in each of thickness. Among sixteen's ultrasonic motors, heat loss on applied voltage was much at stator of the highest resonant point, but heat loss on applied voltage was almost neglected at the lowest resonant point of stator. The thickener thickness of elastic body, revolution speed was decreased. The more slot of elastic body, revolution speed was increased. Applied voltage was changed from $10V_{max}$ to $100V_{max}$. When applied voltage was under $20V_{max}$, ultrasonic motor was not rotated. When applied voltage was over $90V_{max}$, revolution of ultrasonic motor was saturated. Maximum revolution speed was 510[rpm].