• Journal of the Korean Society for Precision Engineering
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• v.25 no.5
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• pp.15-21
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• 2008

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.162-170
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• 2005

In KSLV-I, actuation system for thrust vector control of kick motor was configured as electro-hydraulic servo actuation system and consisted of actuators, hydraulic power supply system, hydraulic power distribution system and control system. In case of hydraulic power supply system, we use EMDP(Electric Motor Driven Pump) to supply hydraulic power. Generally, we use brushed DC motor for EMDP but it is not easy to operate EMDP using brushed DC motor at a high altitude. Hence, we are developing EMDP using brushless DC motor to use at a high altitude. In this study, we will explain control system for BLDC motor to drive hydraulic pump.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.821-823
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• 2002

브러시리스 직류 전동기(Brushless DC Motor : BLDCM)는 기존의 직류 전동기의 단점인 브러시를 제거한 것으로 제어가 간단하면서도 넓은 범위에서 속도 제어가 가능하고 효율이 높으며 저가로 제어기 제작이 가능하다. 그러나 BLDC기을 구동하는데 필수적인 센서는 제품의 가격을 증가시킬 뿐만 아니라 외부 환경-특히 온도의 영향을 많이 받는다는 단점이 있다. 이러한 것은 BLDCM의 사용 환경이 다양해짐에 따라 많은 문제점을 야기하게 되며 따라서 센서리스 구동이 요구된다. 본 논문에서는 BLDCM의 센서리스 구동에서 정상상태 운전뿐만 아니라 안정된 초기 구동에 관한 연구를 수행한다. 정상상태 운전은 측정된 역기전력을 이용하여 회전자의 위치를 결정함으로써 이루어지며, 초기 구동을 개선하기 위해 환류 다이오드로부터 측정된 전류 신호를 이용하여 초기 구동을 하게 된다.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1117-1119
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• 2003

기존의 사다리꼴형 브러시리스 직류 전동기(BLDCM)의 센서리스 제어는 전류전환 시점을 알기 위하여 홀 센서 대신 단자 전압과 중성점 전압을 이용한다. 하지만, 속도 제어를 위해서는 엔코더나 레졸바와 같은 센서를 사용해야한다. 2극기 BLDC 모터의 경우 단자전압을 이용한 위치정보는 모터 한 회전 당 12번의 신호가 출력된다. 엔코더 혹은 레졸바를 제거하고, 이 신호를 이용하여 속도 정보를 만들 경우, 속도를 만들기 위한 위치 정보의 펄스 간격이 넓게 되어 순시 속도를 만들지 못하게 된다. 이로 인하여 실제 속도의 변화를 민감하게 추정하지 못하게 된다. 따라서 이렇게 만들어진 속도 정보는 실제 시스템에서 사용할 수 없게 된다. 이러한 문제를 해결하려고 본 논문에서는 순시 속도 관측기를 사용한다 단자전압과 중성점 전압에 의한 위치정보를 가지고 순시 속도 관측기를 속도 제어 주기보다 빠르게 갱신함으로써 순시 속도를 예측한다. 또한 이 순시 속도는 속도 제어기로 피드백 되어 속도 센서리스를 실현한다. 이에 대한 타당성은 시뮬레이션을 통해 검증한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.1
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• pp.38-46
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• 2000

This study have established proper mathematical equivalent model of Brushless DC (BLDC) motor and estimated the motor parameter by means of the back-emf measurement as being the step input to the controlled target BLDC motor. And the validity of proposed estimation method is confirmed by the test result of step response. As well, we have designed the reasonable digital controller as a consequence of the root locus method which is obtained from the open-loop transfer function of BLDC motor with hall sensor, and the determination of control gain for variable speed control. Here, revised Ziegler-Nichols tuning method is applied for the proper digital gain establishment, and the system stability is verified by the frequency domain analysis with Bode-plot and experimentation.

• 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.

• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.582-588
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• 2002

This paper presents a efficient sensorless driving strategy for brushless dc motor(BLDCM). By varying PWM switching frequency(4KHz, 6KHz, 8KHz) properly according to the rotating speed, the improvement of the efficiency and the operating characteristics through the wide speed are obtained.. The experimental results show that the proposed method can efficiently improve the sensorless driving performance for BLDCM with trapezoidal back emf.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.48-56
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• 2006

This paper studies particularly applicable method for sensorless PM BLDC motor drive system. The waveform of the motor internal voltages(or back emf) contains a fundamental and higher order frequency harmonics. Therefore the third harmonic component is extracted from the stator phase voltage. The resulting third harmonic signal keeps a constant phase relationship with the rotor flux for any motor speed and load condition. Also because of low resolution of estimated signal obtained by the proposed sensorless algorithm, to improve the wide range of speed response characteristic more exactly, we propose the rotor position signal synthesizer using PLL circuit based on estimated signals. Some experimental results are provided to demonstrate the validity of the proposed control method.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.27-28
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• 2011

본 논문에서는 싱글전류센서를 이용하여 브러시리스 직류 전동기의 속도제어시스템 시뮬레이션 방법 및 그 결과을 제시한다. BLDC 전동기 제어에 매우 중요한 역할을 가지고 있는 피드백 센서 방식으로 싱글 전류검출센서를 이용한 속도제어 방법은 모터 설계의 비용을 낮추고, 심플한 제어기 설계를 가능하게 한다. 또한, 전동기에 손상을 줄 수 있는 오류조건을 감지함으로서 신뢰성을 향상시켜 줄 수 있다. 시뮬레이션에 사용하는 BLDC 전동기는 3상 Y결선 전동기를 모델로 하며 MATLAB/SIMULINK를 사용한 시뮬레이션을 수행하여 그 성능을 분석하였다.