• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.115-118
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• 2001

일반적으로 반도체 제조 공정은 매우 복잡하고 다양한 공정들로 구성된다. 이러한 공정 중 Stage 부분은 웨이퍼에 회로 패턴을 기입하기 위하여 웨이퍼를 미리 지정된 위치로 이송하는 공정으로 매우 높은 정밀도가 요구되고 있다. Stage에 대해서는 x, y, z축 뿐아니라 각 축에 대한 회전까지도 고려한 6축 제어가 수행되어야 한다. 본 논문에서는 stage에 대한 정밀제어의 기반기술로서 선형 BLDC 모터를 이용하여 1축 위치제어 시스템의 제어에 관하여 연구하였다. 선형 BLDC 모터의 이동 중 발생하는 추럭리플을 보상하여 제어기 설계시 선형 시스템으로 고려하여 제어기를 설계할 수 있도록 하는 방법을 제안하였으며 실험을 통하여 1[${\mu}m$]의 해상도를 갖는 위치검출 엔코더를 이용하여 5[${\mu}m$]의 정밀도를 얻을 수 있었다.

• Journal of Power System Engineering
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• v.3 no.2
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• pp.64-69
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• 1999

The paper shows a result for development of BLDC motor drive by using a resolver as position detection sensor. The developed drive use a method detecting rotor position based on HSI interrupt function of microprocessor without a specialized counting circuit. The algorithm generating three-phase PWM wave to change switching voltage and current is realized based on single chip microprocessor. The PWM generating part and position counting circuit are realized by software technique without usage of conventional analogue circuit or object-oriented chips. So the drive system become compact. The effectiveness of the developed drive is verified by experimented results of speed response for step reference input.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.802-808
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• 2019

DC motors are used extensively on shipboard, including as the ship's winch operating motor, owing to their simple speed control and excellent output torque characteristics. Moreover, they were used as propulsion motors in the early days of electric propulsion ships. However, mechanical rectifiers, such as brushes, used in DC motors have certain disadvantages. Hence, brushless DC (BLDC) motors are increasingly being used instead. While the electrical characteristics of both types of motors are similar, BLDC motors employ electronic rectifying devices, which use semiconductor elements, instead of mechanical rectifying devices. The inverter system for driving conventional BLDC motors uses a two-phase excitation method so that the waveform of the back electromotive force becomes trapezoidal. This causes harmonics and torque ripple in the phase current switching period in which the winding wire through which the current flows is changed. Researchers have studied and presented various methods to reduce the harmonics and torque ripple. This study applies a cascaded H-bridge multilevel inverter, which implements a proportional-integral speed current controller algorithm in the driving circuit of the BLDC motor for electric propulsion ships using a power analysis program. The simulation results of the modeled BLDC motor show that the driving method of the proposed BLDC motor improves the voltage waveform of the input side of the motor and remarkably reduces the harmonics and torque ripple compared with the conventional driving method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.869-873
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• 2008

Optimization method for the open loop commutation time intervals in HDD spindle start-up control is presented in this paper. A hard disk drive(HDD) uses a sensorless brushless DC motor(BLDC) for the platter rotation. Because there is no direct sensor for the rotor position, open loop commutations after sensing the rotor position at a standstill using inductive sensing method are performed to speed up the rotor up to a certain speed where the zero crossings of the back electromotive force(EMF) are measurable. Therefore successful open loop commutations are necessary for the stable start-up control of the spindle motors. Random neighborhood search(RNS) algorithm is introduced as a optimization technic in this paper. Rotor speed and its standard deviation are used as a cost function and commutation intervals obtained from the spindle motion equation are used as initial parameter values for the RNS. With the help of the proposed method optimized open loop commutation time intervals for the very low start-up current are acquired and tested. The experimental results shows that the proposed method can decrease the start-up failure rate of a HDD spindle motor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.54-59
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• 2005

Brushless DC motor is a motor which is modified form DC brush motor and it does not have brushes. BLDCM is easy to centre, has wide speed range, high efficiency. However it needs speed sensor like encoder which increases the motor price and cause some faults in poor surroundings.. In this paper, for the sensorless control, the driving techniques for the initial stable start and the steady state are studied For the steady state the rotor position is determined using the measured back-EMF. To enhance the initial stating performance, the current signal from the free-wheeling diode is used. The results are conformed through the experiments.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.77-78
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• 2006

A mixed method between $H_2\;and\;H_{\infty}$ control are widely applied to systems which has parameter perturbation and uncertain model to obtain an optimal robust controller. Brushless Direct Current (BLDC) motors are widely used for high performance control applications. Conventional PID controller only provides satisfactory performance for set-point regulation. However, with the presence of nonlinearities, uncertainties and perturbations in the system, conventional PID is not sufficient to achieve an optimal robust controller. This paper presents an approach to ease designing a Mixed $H_2/H_{\infty}$ PID controller for controlling speed of Brushless DC motors and the genetic algorithm is used to solve the optimized problems. Numerical results are shown to prove that the performance in the proposed controller is better than that in the optimal PID controller using LQR approach.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3323-3328
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• 2007

Conventional LPG pump for Liquified Petroleum injection(LPi) engine has been adopted vane type. But the BLDC type fuel pump for LPi system has complicated structure and its price is high. Therefore, as a alternative, this study has mainly focused on the development of turbine type LPG pump which has lower cost and simple structure than conventional BLDC type. To verify the possibility of substitute the performance tests were performed for each fuel pump. The comparative items were pressure settling time, variation of fuel outlet temperature and engine performance of hot restart ability. As a result, performances of turbine type LPG pump were equivalent or high comparing to the BLDC type all over the tests for different fuel composition.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.9
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• pp.417-422
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• 2001

The brushless DC motor(BLDCM) is widely used in many applications. One of the application of the BLDCM is the stage which is one of process in the semiconductor manufacturing processes. Very high performance is required in the stage process. In this paper, the 1 degree of freedom positioning system for the basic technology of the stage is studied. The linearization method is proposed to make the controller design procedures easy by measuring the thrust force ripple using the strain gauge. And through the experiments, it is proved that the inner velocity control loop is necessary to make more precise positioning control system.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.2
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• pp.134-143
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• 2016

This paper proposes a novel asymmetrical interior permanent magnet (IPM) brushless DC (BLDC) motor structure, which utilizes half-type permanent magnet (PM) configuration and has asymmetrical side gaps (slot next to the PMs) for reducing torque ripples. This structure uses 24% less volume of PMs than conventional IPM BLDC motor with a full set of magnets. The characteristics of the proposed motor are compared with three other half-type IPM BLDC motors through finite elements method (FEM) analysis, and the usefulness of the proposed motor was verified through experimental evaluation on prototypes of the conventional motor and proposed motor under various torque load conditions. This research obtained a high-performance IPM BLDC motor while decreasing manufacturing cost at the same time.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.99-105
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• 2007

Currently, BLDC fuel pump was applied on LPi vehicle using 3rd fuel supply system as liquified phase LPG injection method had already shown better performance than others. Its cost, however, is rather expensive because of drawbacks such as complicated structure, a fault of localization of system. In this work, demonstration system for a developed turbine type fuel pump to replace BLDC system was setup and investigated. This study results that fuel mass flow rate of turbine type pump and injection performance of injector were better compared to BLDC type. Comparing flow rate of summer LPG with that of winter LPG, the flow rate decreased about 25% using winter LPG. Performance applying turbine type LPi fuel pump to engine is confirmed.