• 전기학회논문지
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• 제66권12호
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• pp.1725-1731
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• 2017

In hysteresis simulation, the Preisach model is most widely used as the reliability. However, since the first-order transition curves used in the conventional Preisach model are very inconvenient for actual measurement, many researches have been made to simplify them. In this study, the minor loops obtained along the initial magnetization curve are used to obtain the Everett function used in the Preisach model. In other words, The Everett table is constructed by using the minor loops, and are applied to the magnetization dependent Preisach model to reconstruct the Everett table. In order to minimize the error, the spline interpolation method is used to complete the final Everett table and the hysteresis loop simulation is performed with the Everett table. Furthermore, it is applied to the inductor analysis to perform not only sinusoidal wave and square wave drive but also PWM wave drive considering hysteresis. The validity of the proposed method is confirmed by comparison with simulation and experiment.

• 조명전기설비학회논문지
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• 제19권8호
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• pp.122-130
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• 2005

롤-스크린의 조용한 동작을 위해 압전 초음파 모터를 사용하여 롤-스크린이 설계되었다. 롤-스크린에 사용된 초음파 모터를 구동하기 위하여, 디지털로 제어되는 구동회로가 PLD를 사용하여 설계되었다. 또한 롤-스크린의 위치와 속도를 측정하기 위하여 1회전 당 36펄스의 엔코더가 사용되었다. 이러한 저급 엔코더를 사용함에도 불구하고, 초음파 모터의 정밀한 속도제어를 위하여 새로운 제어 방법이 제안되었다. 제안된 방법은 가변 샘플링시간을 사용하고 있으며, 초음파모터가 가지는 초기 비선형 특성 문제를 보상하도록 하였다.

• 전력전자학회논문지
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• 제12권3호
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• pp.205-212
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• 2007

본 논문에서는 토오크 맥동을 줄이고 동특성 및 효율을 개선하기 위해 새로운 4-레벨 콘버터 이용한 DITC SRM 구동방식을 제안하였다. 4-레벨 콘버터는 콘덴서의 전압을 이용하여 여자 및 감자 시 높은 전압을 인가하여 여자특성을 개선할 수 있는 장점을 가진다. 본 논문에서는 DITC의 동특성 개선을 위해 사용된 4-레벨 콘버터의 동작특성과 부스트 전압에 따른 효율 개선에 대해 해석하였다. 이를 통해 제안된 SRM을 위한 4-레벨 콘버터의 DITC 제어기법을 시뮬레이션과 실험을 통해 검증하였다.

• 전기학회논문지
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• 제61권1호
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• pp.50-56
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• 2012

The Multi D.O.F spherical motor can drive rotating as well as tilting three degree of freedom with one motor. Existing three degree of freedom to drive with three motors that are connected by gears and belts, that will be too large size and big loss at gears and belts. So Reducing system size and improving efficient is using the Multi D.O.F spherical motor in three degree of freedom systems. For this reason, efficiency of Multi D.O.F spherical motor is one of the important performance indiccators. In this paper presented that how to improve the efficiency of the Multi D.O.F spherical motor. The fist of method is using the stator iron core's material with high permeability and resistivity for reducing the eddy current loss. However, it was the disadvatages of motor-making and economic. So author propose the resonable method of reducing the eddy current loss in the stator iron core. That is using the rotor with double-air gap.

• 한국정밀공학회지
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• 제17권8호
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• pp.157-164
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• 2000

This paper presents a method to detect a rotor position and to drive a BLDC motor from standstill to medium speed without any position sensor comparing the current responses due to the inductance variation in the rotor position. A rotor position at a standstill is identified by the current responses of six pulses injected to each phase of a motor. Once the motor stars up pulse train that is composed of long and short pulses is injected to the phase corresponding to produce the maximum torque and the next phase continuously. it provides not only the torque but also the information of the next commutation time effectively when the response of long and short pulses crosses each other after the same time delay. This method which is verified experimentally using a DSP can drive a BLDC motor to the medium speed smoothly without any rattling and time delay compared with the conventional sensorless algorithm.

• 한국소음진동공학회논문집
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• 제17권6호
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• pp.477-483
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• 2007

Major noise source in high speed rotating optical disk drives (CD and DVD-ROM) arises due to the high-speed airflow produced from the upper and lower surfaces on the rotating disk. The present paper deals with the experimental approach how to identify the noise source based on the fundamental principles of aeroacoustics and to propose a reduction method of the noise source. The CD-ROM device is composed of disk, window tray, motors at the bottom place and electronic circuit plate also located below the window plate. The window is cut in the tray to read the disk information using the optical device located below the tray and moving linearly from the center of the disk through the end of the disk. All components are possible noise generators. Experimental studies were carried out in the anechoic room with various design modifications, such as tray geometry, window size and hole location on tray, to identify the major aerodynamic noise source and significant reductions of the aerodynamic noise were obtained.

• Journal of Power Electronics
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• 제19권1호
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• pp.146-157
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• 2019

The inverter is an essential part of permanent magnet synchronous motor (PMSM) drive systems. The performance of an inverter is greatly influenced by its modulation strategy. Using a proper management of modulation strategies can guarantee high performance from a PMSM under various speed conditions. Switching between modulations is a pivotal technique that determines the performance of a PMSM. Most works on hybrid methods focus on two-level induction motors drive systems. In this paper, in order to improve the performance of PMSMs under various speed conditions, a hybrid method of a pulse width modulation (PWM) control scheme based on a neutral-point-clamped (NPC) three level topology was proposed. This hybrid PWM modulation comprised space vector PWM (SVPWM) and selective harmonic elimination PWM (SHEPWM). Under low speed conditions, the SVPWM is employed to cause the PMSM to start smoothly, and to obtain a rapid response from the control system. Under high speed conditions, the SHEPWM is employed to reduce the switching frequency and to eliminate particular current harmonics. Moreover, the harmonic characteristics of different modulations are analyzed to obtain a smooth transition between the SHEPWM and the SVPWM. Experimental and simulation results indicated the effectiveness of the proposed control method.

• 정보저장시스템학회논문집
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• 제2권3호
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• pp.208-213
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• 2006

The present state of the design of swing arm actuators for optical disc drives is to obtain the high efficient dynamic characteristics within a very compact volume. As a necessary consequence, the need of the small form factor (SFF) storage device has been arisen as major interests in the information storage technology. In this paper, we suggest the miniaturized swing arm type actuator that has high efficient dynamic characteristics for SFF optical disk drive (ODD). For the operating mechanism, it uses a tracking electromagnetic (EM) circuit for a focusing motion together. Moreover, due to the size constraint, the thermal stability of optical head is important. Therefore, the actuator is designed to emit the heat, which is generated by optical pick-up, along the actuator body easily. Initial model is designed based on the topology optimization method considering the thermal conductivity. Then, the structural parts of the actuator are modified to maintain the high sensitivity and to have wide control bandwidth by the design of experiments method (DOE) and new concept of decreasing mass and inertia. Finally, a swing arm type actuator for SFF ODD is suggested and its dynamic characteristics are verified.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2009년도 정기총회 및 추계학술대회 논문집
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• pp.252-255
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• 2009

This paper proposes a new loss minimization controller (LMC) for induction motor drive. The proposed LMC presents a strategy to minimize the total power losses of induction motor (IM), which is based on simplified equivalent circuit and simplified model of IM. The proposed controller using the field oriented control (FOC) method is to determine an optimal rotor flux for obtaining the minimum total power losses and higher efficiency. Simulation and experimental results are given to validate the effectiveness of the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1235-1237
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• 1992

In this paper, a new PWM method and estimating means of rotor position angles for BLDC motor drive are presented. The rotor position angles is predicted by calculated rotor flux from the stator voltage and current signals. The current control PWM using fuzzy logic is also suggested. Performance of the proposed controller is observed through a simulation.