• 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 KIPE Conference
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• 2018.07a
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• pp.416-417
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• 2018

Brushless DC(BLDC) 모터는 브러시가 없어 고속 회전에 유리하기 때문에 핸드피스 모터에 많이 적용하는 추세이다. 핸드피스 모터는 부피가 작을수록 유리하여 홀 센서를 장착하지 않은 경우가 많기 때문에 센서리스 제어를 하여야 한다. BLDC 모터의 상 역 기전력 zero crossing 감지 방법을 이용한 센서리스 제어를 할 시 40,000rpm에 달하는 고속 회전에서 상 전압 floating 구간이 $250{\mu}s$밖에 안되기 때문에 샘플링이 부족하고 스위칭 노이즈도 강해 zero crossing에 대한 감지가 어려울 수 있다. 이 논문에서는 역 기전력에 대한 비선형 필터인 majority function을 응용함으로써 모터 상 역기전력의 zero crossing을 감지해내고 고속 BLDC 모터 센서리스 제어를 하는 방법을 소개한다.

• 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.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.114-121
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• 2013

High efficiency operation is required for motors of vehicle to increase fuel efficiency due to the regulation of exhaust gas. This paper presents a control method of fuel pressure to increase fuel efficiency and a sensorless control method of BLDC motor to get higher efficiency than conventional brushed DC motor. Initial rotor position of BLDC motor is detected from current value that is occurred by test voltage pulse and rotor is accelerated by defined sequence to enter sensorless operation mode. The algorithm to control flow rate of fuel pump uses PI controller that is control motor speed to maintain the target fuel pressure commanded by ECU.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.847-852
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• 2007

This paper investigates the characteristics of cogging torque and magnetic force of a brushless DC (BLDC) motor due to imperfect magnetization of permanent magnet (PM) numerically and experimentally which results in the magnetically induced vibration. A predicted magnetization pattern of the PM of the BLDC motor, which is derived from the measured surface magnetic flux density along the PM, is applied to the finite element analysis in order to calculate the cogging torque and the unbalanced magnetic force. This research also develops the experimental setup to measure the unbalanced magnetic force as well as the cogging torque. It shows numerically and experimentally that the imperfect magnetization of permanent magnet generates the driving frequencies of cogging torque with integer multiple of slot number in addition to the least common multiple of pole and slot. It also shows that the driving frequencies of unbalanced magnetic force are integer multiple of slot number ${\pm}1$ due to imperfect magnetization of PM even in the rotationally symmetric design.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.8
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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.

• 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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.10
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• pp.1065-1072
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• 2008

A HDD adopts a sensorless brushless DC (BLDC) motor as a spindle motor. Because there is no direct sensor measuring rotor position. open loop commutations with inductive sensing are used to increase the rotor speed up to a certain speed where the zero crossings of the back electromotive force (EMF) voltage are measurable. Therefore, successful open loop commutations are necessary for the stable start-up control of the spindle motors. In this paper, the time scale and the number of the open loop commutations are employed for design parameters to guarantee robustness to torque constant variation and initial rotor position. The design results are verified by experiments on a very low current start-up of the spindle motor with various environment. The experimental results show that the design results can decrease the start-up failure rate considerably.

• 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.