• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.398-404
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• 2021

This paper proposes a method of using a magnetic position sensor to detect accurately the rotor position required to perform vector control of a permanent-magnet synchronous motor, particularly the initial rotor position at startup. In the existing vector control systems, the initial rotor position was determined using the output signals of the Hall sensors, or the control was performed in a sensorless method without using such a sensor. On the other hand, the accuracy is degraded due to the occurrence of a position detection error, and the practicality was not satisfactory. This paper attempts to detect the initial rotor position using a magnetic position sensor to solve this problem. This method is used to solve the deteriorating starting characteristics of the motor in the vector control system. In addition, to lower the price of a low-power vector control inverter, this paper proposes a method of integrating the existing sensors and reducing the price to less than half using a magnetic position sensor for speed and position detection.

• Korean Journal of Crystallography
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• v.6 no.2
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• pp.88-92
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• 1995

Higly pure silicon crystals with an almost perfect lattice structure constityte a powerful metrological tool. The streographic standard prohection for the (111) orientation of diamond structure found by the Laue method shows angles between net planes of 60°. This value is known to be certain to some 10-8 rad. We have made a six-faced silicon polygon, and the (220) lattice planes of the polygon act as a reference angular standard. The information of angles between lattice planes could be taken by the X-ray diffraction. The angle of the rotary encoder have been calibrated using the silicon angle standard. The X-ray optics was double crystal arrangement.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.1
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• pp.63-69
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• 2008

The position of stator is essential when a trapezoidal BLDC motor is drived. In this paper we proposed a novel sensorless drive system for the trapezoidal BLDC motor without hall sensors or encoders. The resistor Y-connecting method is used to obtain Back-emf of a trapezoidal BLDC motor. Especially, by using the new Back-emf filter circuit proposed in this paper the sensorless characteristic in low speed is improved. The prototype proposed system applied for a 100[W] rating BLDC motor is made and the propriety of the Back-EMF filter circuit is also verified.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.5
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• pp.488-493
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• 2005

This paper presents a method of detecting rotor position for single phase Switched Reluctance Motors(SRMs) using a search coil. In the single phase SRM, mainly Hall effect sensors or photo interrupters have been used to detect the rotor position. But these sensors have many disadvantages. In this paper, low cost and robust characteristics of rotor position detection method are focused in order to compensate for disadvantage of existing sensors. Search coils wound around the stator pole are used for detection of the rotor position in single phase SRM. Rotor position detection is achieved through electromotive force patterns induced by time-varying flux linkage in the search coil. The simulation and experimental results are presented to verify the performance of the proposed method in this paper.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.141-146
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• 2020

In brushless DC motors (BLDC), the on/off angle of the switch is determined by the optimal alignment of the stator and rotor, while switched reluctance motors (SRM) are complex parameters with many on/off angles of the switch. It appears as a function and therefore the switching angle is variable for optimal operation. Therefore, in order to operate the switched reluctance motor (SRM) optimally, the rotor position can be detected using a high resolution position sensor and a complicated additional circuit. In this paper, rotor position detection and related position detection circuits are applied and detected by using various sensors such as encoder, hall sensor and opto interrupter among several methods to drive switched reluctance motor (SRM). Also a study on securing the initial position of the rotor was conducted.

• Korean Journal of Optics and Photonics
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• v.23 no.6
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• pp.241-245
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• 2012

Measurements of the optical activity become very important issues in fields related to polymers, optical communications, astronomy, physics and many more. Hence it need to introduce this subject in our regular curriculum. In this experiment, an inexpensive, reliable, motorized polarimeter system which is suitable for undergraduate courses is constructed with PASCO's well-known Science Workshop 750 and a rotational motion sensor and light sensor, and the system is presented along with its experimental formulas. After responsivity of this system was checked by a half wave plate, and some repetitive experiments with 30% sucrose solution at 543.8 nm were performed. Comparing the experimental result with two calculated values from CRC data[1] showed that the specific rotation of the sucrose sample could be strongly suggested to be around +76 deg.cc/g.dm and it was an amply acceptable result for most undergraduate level courses.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.4
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• pp.336-343
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• 2003

Generally, brushless DC motor(BLDCM) driving system uses hall sensors or encoders as the mechanical position or speed sensors. It is necessary to achieve the information's of rotor position for driving trapezoidal type brushless DC motor without any position sensor. This paper proposes a sensorless driving system with absolute rotor position detecting circuit which acquires both commutating phase and commutating time by analyzing motor phase voltages. Proposed system is applied to a 10k[W] rating motor which actually used in Hybrid Electric Vehicles. The experimental results will show the validity of the proposed system and the practical use of proposed sensorless drive.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.127-132
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• 2017

In this paper, we propose a controller gain based on model based design and implement the two-wheel inverted pendulum type robot using NXT Lego and RobotC language. Two-wheel inverted pendulum robot consists of NXT mindstorm, servo DC motor with encoder, gyro sensor, and accelerometer sensor. We measurement wheel angle using bulit-in encoder and calculate wheel angle speed using moving average method. Gyro measures body angular velocity and accelerometer measures body pitch angle. We calculate body angle with complementary filter using gyro and accelerometer sensor. The control gain is a weighted value for wheel angle, wheel angular velocity, body pitch angle, and body pich angular velocity, respectively. We experiment and observe the effect of two-wheel inverted pendulum with respect to change of control gains.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.876-877
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• 2011

Variable Reluctance(VR) 레졸버는 엔코더를 대신해 Hybrid Electric Vehicle (HEV) / Electrical Vehicle(EV) 및 자동화 산업 전반에서 위치센서로써 사용되고 있다. VR 레졸버는 두 개의 출력신호(SIN, COS)를 발생시키며, Resolver-to-Digital Convert(RDC) 알고리즘을 통하여 위치신호로써 변환된다. 위치센서로써의 VR 레졸버는 무엇보다도 회전자의 정확한 위치를 찾아내는 것이 중요하다. 위치 정보의 오류를 발생시키는 원인으로는 다양한 것들이 있다. 본 논문에서는 VR 레졸버 형상을 변화시킴으로써 인해 레졸버를 통해 나온 출력신호에 포함된 각도정보의 정밀도 향상을 위해 FEM 해석을 통해 연구 및 분석 하였다.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.274-276
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• 2009

최근 화석연료의 연소로 인해 발생되는 이산화탄소에 의한 환경오염이 크게 대두가 되고 있으며, 특히나 내연기관 자동차의 배출가스는 이산화탄소의 배출량이 매우 높은 실정이다. 따라서 정부에서는 친환경자동차 분야를 하나의 성장사업으로 선정하였으며, 이에 대한 많은 연구 개발이 진행 중에 있다. 본 논문에서는 출퇴근용으로 사용할 수 있는 근거리 전기자동차용 10kW급 BLDC 모터 제어기 개발에 대하여 제안을 한다. 제안된 근거리 전기자동차용 10kW급 BLDC 모터 드라이브 제어기는 한정된 공간 및 배터리 전원에서도 고토크, 고출력, 고효율, 경량화의 장점을 가지도록 개발을 하였다. 또한, BLDC 모터는 회전자 위치 정보가 필수적으로 요구되기 때문에 다양한 위치 센서를 사용할 수 있도록 홀센서, 엔코더, 레졸버를 사용할 수 있도록 모터제어기를 개발 하였다. 제안된 방식의 타당성 검증을 위해 PSIM을 이용하여 시뮬레이션 수행하였으며, 10kW급 BLDC 모터 드라이브 제어기를 제작하여 성능을 검증하였다.