• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.6
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• pp.223-232
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• 2001

Aiming at a small axial pump with a levitated rotor, an axial-type self-bearing motor is presented, which has a rotor wish four permanent magnets and two stators with two-pole three-phase windings. In this system, only the axial motion of rotor is actively controlled by two opposite self-bearing motors just like in the case of an axial magnetic bearing, while the other motions are passively stable. For rotation, It follows the theory of a four-pole three-phase synchronous motor. This paper Introduces schemes for design and control of the self-bearing motor and shows some experimental results to Prove the feasibility of application for the axial Pump.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.133-138
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• 2022

Digital radiation inspection equipment is a medical device that deals with human life and requires stability and high reliability. However, this system is currently the most advanced technology and the domestic market is almost occupied by European products including Japan. Therefore, research and development are needed not only to replace domestic medical devices, which are largely dependent on expensive imported products, but also to develop more economical and user-oriented products that are easy to operate and produce devices that lead to accurate diagnosis. In particular, among the digital X-ray systems, the motor driving technology and the mechatronics technology related to the development of mechanical devices have matured to some extent in Korea. In this paper, selection of AC servomotor for digital radiation inspection suitable for imaging purpose, and application of conversion device and control method to check performance and improve problems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.9-14
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• 2013

Model based design method reduces product development period and increases system software safety. In this paper, a BLDC motor controller based on model based design method is designed with Simulink and implemented with auto generated code which is written in C language. To retain the safety of software, this model is implemented according to MISRA AC SLSF guide. The validity of the implemented controller is verified with a real position control experiment, and execution times of each control loops are measured to compare the system performance of the conventional design and the model based design.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.106-108
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• 2008

This paper deals with the design for speed controller to drive PMSM by matrix converter without DC-link circuit as the power conversion system of AC servo motor drive. To design the speed controller of PMSM drive, the closed-loop transfer function of speed controller is calculated and then the frequency-domain response characteristics are analyzed by bode plot using Matlab. Based on the results by bode plot, the speed control gains are determined. As the real effects of controller designed in the frequency-domain display in the time-domain, the performance of speed controller is confirmed by the step response of speed controller. The design examples are shown and its validity of the design method mentioned in the paper is verified through PSIM simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.5
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• pp.711-716
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• 2012

To assess the insulation deterioration of stator windings, diagnostic and AC breakdown tests were performed on the eleven high voltage (HV) motors rated at 6kV. After completing the diagnostic tests, the AC overvoltage test was performed by gradually increasing the voltage applied to the stator windings until electrical insulation failure occurred, to obtain the breakdown voltage. Stator winding of motors 1, 3, and 8 failed at above rated voltage at 14 kV, 13.8kV, and 16.4kV, respectively. The breakdown voltage of three motors was higher than expected for good quality windings in 6kV motors. Based on deterioration evaluation criteria, the stator winding insulation of eleven HV motors are confirmed to be in good condition. The turning point of the current, $P_{i2}$, in the AC current vs. voltage characteristics occurred between 5kV and 6kV, and the breakdown voltage was low between 13.8kV and 16.4kV. There was a strong correlation between the breakdown voltage and various electrical characteristics in diagnostic tests including Pi2.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.3
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• pp.207-217
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• 2010

Recently, the use of DC power increased due to the increased use of digital load. Power factor of input current decrease and input current harmonics increase, and conversion loss which is occurred in the AC / DC converter is a problem to provide the proper DC voltage to the device equipped with an internal AC / DC converter. Hybrid system supplies the AC power and DC power to AC load (motor load and the transformer load) and DC loads (computers, TV, LED fluorescent light) at the same time it supplies the renewable energy and utility energy taken power from Utility to user for improving the efficiency and renewable energy improvements in ease of use. This paper studies DC characteristics of traditional AC load for Hybrid distributions.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.149-153
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• 2003

AC 부하를 갖는 동기전동기에 있어서, 동기전동기의 속도리플을 저감시키기 위한 문제를 풀기위해 3가지 제어기법에 대해 비교를 한 후 가장 강인한 제어기법에 대해 분석하였다. AC 부하를 갖는 특별한 제어 대상으로 엑스선 전산화 단층촬영 장치(CT)용 겐트리를 선정하였으며 시스템이 갖는 특별한 구조에 의해 이러한 시스템 특성을 갖는다. 동기전동기의 출력 축에 링(Fing) 모양의 원판 프레임을 갖으며, 이 원판 표면에 무게가 서로 다른 여러 장치(X_선 튜브, X-선 검출기, 고압발생장치, DAS 장치, 온도조절장치 등)를 부착하여 영상 획득 시스템의 회전부를 구축하기 때문이다. 이러한 시스템에서는 무게 평형을 갖지 못하는 편심 무게가 존재하게 되며 이로써 전동기 관점에서는 AC 부하처럼 인식되는 제어 조건으로 인식 될 수 있다. AC 부하를 갖는 동기전동기에 대해 일반적인 벡터제어 알고리즘으로 제어를 수행하면 정상상태에서도 속도 오차가 "0" 으로 줄어들지 않고 AC 형태의 오차 성분이 존재하며 편심 무게의 크기에 비례하여 진폭이 커지는 특성을 갖는다. 이러한 문제점을 해결하기 위하여 Sine파 보상전류를 갖는 속도제어기법, 펀심부하토크 관측기를 이용한 속도제어기법, 그리고 기준모델제어기법을 소개하였다. 각 방법에 대한 실험 결과로부터 편심무게의 변동과 편심 위치의 변동 조건에서 기준모델제어기법이 강인한 제어 특성과 리플저감 측면에서 가장 우수함을 검증하였다. 이로써 AC 부하 조건에서 고정도 속도 제어기가 요구되는 경우 좋은 선택의 지침이 될 수 있다고 본다.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1158-1160
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• 2002

In this paper, we presents sliding surface design techniques using the virtual state. This sliding surface has same dynamic of nominal system and permit application with other controller. If select initial value of the virtual state properly, problem of reaching phase disappears. And applied in AC servo motor's speed control to show performance of proposed sliding mode control techniques.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.25-28
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• 1996

Recently, AC variable-speed motors are used for many steel rolling mill drive systems, because of their low maintenance and enhanced control performance. We have been applied GTO inverters for these AC motor drive systems since 1993. We have developed world largest 6-inch diameter GTO and large capacity 3-level GTO inverter up to 20000(kVA). As an example, in this paper, we describe the main circuit, system arrangement and control features of the 6-inches GTO inverters to drive rougher mills for hot strip mill of Pohang Iron & Steel Co., Ltd. The motor capacity is 6000(kW), and it's overload is 250(%).

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2769-2772
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• 2003

This paper presents results of the development of the Turbo-generator system with structure which is HSG(High Speed Generator) installed to high speed gas-turbine engine directly. Turbo-generator with high speed motor-generator directly has many advantages aspects of weight, size, lubrication system and complexity of the system compared of conventional turbo-generator system with gear-box. But because of direct high speed operation of the high speed generator, we have to need stable high speed motor driving algorithm for perfect engine ignition when gas turbine starting. Also we have to need design of the PCU(Power Conditioning Unit) for converting high speed AC output power to conventional AC power or needed DC power.