• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.962-966
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• 2004

Ball screw feed drive systems have been broadly used in machine tools or precision automatic feed systems. Recently, modern machine tools require high speed and high precision and drive system to achieve high productivity. Unfortunately, a feed drive system, even though it was optimum designed, may experience severe transient vibrations during high-speed operation if its feed rate control is unsuitable. A rough feed rate curve having discontinuity in its acceleration profile causes a serious vibration problem in the feed slide system. This paper presents a feed rate optimization of a machine tool feed slide system, which is driven by a ball screw, for its minimum vibrations. Firstly, a 6-degree-of-freedom lumped parameter model was proposed for the vibration analysis of a ball screw driven machine tool feed drive system. Next, a feed rate optimization of the feed slide was carried out for minimum vibrations. The feed rate curve optimization strategy is to find out the most appropriate acceleration profile having finite jerk. Of course, the optimized feed rate should approximate to the desired one as possible. A genetic algorithm with variable penalty function was used in this feed rate optimization.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.3133-3141
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• 2011

The next generation domestic high speed railway system is a power distributed type and uses vector control method for motor speed control. Nowadays, inverter driven induction motor system is widely used. However, recently PMSM drives are deeply considered as a alternative candidate instead of an induction motor drive system due to their advantages in efficiency, noise reduction and maintenance. The next-generation high speed train is composed of 2 converter units, 4 inverter units, and 4 Traction Motor units. Each motor is connected to the inverter directly. In this paper, the effect of IPMSM parameter variations to the system operation characteristics of the multi inverter drive high speed train system are investigated. The parallel connected inverter input-output characteristics are analyzed to the parameter mismatches of IPMSM using the 1C1M control simulator based on Matlab/Simulink.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.528-535
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• 2002

In order to achieve high precision machine tools, the research for performance enhancement of feed drive systems is required. Development of the high speed feed drive system has been a major issue for the past few decades in machine tool industries. The reduction of the tool change time as well as rapid travel time can enhance the productivity. However, the high speed feed drive system generates more heat in nature, which leads thermal expansion that has adverse effects on the accuracy of machined parts. Stick-slip friction has a great influence on the contouring accuracy of CNC machine tools. In this paper table levitation system has been developed for the stick-slip in a feed drive systems. And also, the driving position is set near the center of the main slideway. From the results, it is confirmed that yaw error and straightness can be improved.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.190-198
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• 2002

In switched reluctance motor(SRM) drive, it is necessary to synchronize the stator phase excitation with the rotor position. Therefore the rotor position information is an essential. Usually optical encoders or resolvers are used to provide the rotor position information. These sensors are expensive and are not suitable for high speed operation. In general, the accuracy of the switching angles is dependent upon the resolution of the encoder and the sampling period of the microprocessor. But the region of high speed, switching angles are fluctuated back and forth from the preset values, witch are cause by the sampling period of the microprocessor. Therefore, the low cost linear encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper It is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate for the practical low cost SRM drive.

• 전기학회논문지P
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• 제59권3호
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• pp.279-287
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• 2010

Interior permanent magnet synchronous motor(IPMSM) adjustable speed drives offer significant advantages over induction motor drives in a wide variety of industrial applications such as high power density, high efficiency, improved dynamic performance and reliability. This paper proposes efficiency optimization control of IPMSM drive using adaptive fuzzy learning controller(AFLC). In order to optimize the efficiency the loss minimization algorithm is developed based on motor model and operating condition. The d-axis armature current is utilized to minimize the losses of the IPMSM in a closed loop vector control environment. The design of the current based on adaptive fuzzy control using model reference and the estimation of the speed based on neural network using ANN controller. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal control of the armature current. The minimization of loss is possible to realize efficiency optimization control for the proposed IPMSM. The optimal current can be decided according to the operating speed and the load conditions. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using AFLC. Also, this paper proposes speed control of IPMSM using AFLC1, current control of AFLC2 and AFLC3, and estimation of speed using ANN controller. The proposed control algorithm is applied to IPMSM drive system controlled AFLC, the operating characteristics controlled by efficiency optimization control are examined in detail.

• 인터넷정보학회논문지
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• 제13권3호
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• pp.83-91
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• 2012

최근 컬럼-기반 저장 장치는 우수한 입출력 성능으로 고속 데이터베이스 시스템의 진보적인 중요 모델이 되었다. 본 논문에서는, 기존의 가로-기반 저장 모델과 비교 분석하고, 고속 컬럼-기반 데이터베이스 시스템의 유효 성능을 향상시키기 위하여, 플래시 메모리와 어시스트 드라이브를 활용한 새로운 컬럼-인지 스토리지 관리 모델을 제안한다. 컬럼-인지 폴라라이징이라고 하는 본 스토리지 관리 기법은 테이블 컬럼을 활성-컬럼과 비활성-컬럼으로 양분하여 압축 저장하며, 고부하시에 어시스트 드라이브를 활용하여 적체된 저장 연산을 리벨런싱한다. 실험 결과는 본 제안 기법이 컬럼-기반 스토리지의 초당 저장 연산 처리치를 19% 개선하였고, 그 응답 성능도 49%개선되었음을 보였다.

• 전력전자학회논문지
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• 제21권5호
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• pp.381-387
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• 2016

Many efforts have focused on the improvement of power density and efficiency by downsizing the motor and inverter. Recently, Toyota, Honda, and GM realized that the compact-sized motor uses the hairpin structure with increased space factor. Reducing the maximum torque from high-speed technique also makes it possible to design the high-power density model. Toyota and Honda used the newly developed power semiconductor IGBT to decrease conduction loss for high-efficiency inverter. In particular, Toyota used the boost converter to increase the DC link voltage for high efficiency in low-torque high-speed region. Toyota and GM also used the double-sided cooling structure for miniaturization of inverter for high-power density.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.1059-1062
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• 2002

In this paper, after we make high speed gear requested high precision, we got data on the sound level is Max 60,000rpm for tooth modification. We make a decision about tooth modification after predicting exactly amount of tooth interference by FEM. The purpose of this research is that modified gear is to drive under stable sound level. To accomplish its, Beam elements are used to simulate the same condition as a real gear drive by FEM. From result of simulation and experiment, if it has holes to decrease whole weight of high speed gear, it is not good effect because it has much more deformation than not.

• 조명전기설비학회논문지
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• 제23권10호
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• pp.59-68
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• 2009

유도전동기의 벡터제어는 고성능 적용에서 광범위하게 사용되고 있다. 그러나 이러한 드라이브 성능은 파라미터 변동에 의한 동조는 여전히 한계가 있다. 다양한 속도영역에서 운전하기 위하여 종래에는 PI과 같은 제어기를 보통 사용하였다. 이러한 제어기들은 이상적인 벡터제어 조건에서 광범위한 운전에 대하여 제한된 양호한 성능을 나타낸다. 본 논문은 다중 적응 제어기를 사용하여 유도전동기 드라이브의 고성능 제어를 제시한다. 이 제어기는 FAM(Fuzzy Adaptation Mechanism)에 의 해 속도제어, MFC(Model Reference Adaptive Fuzzy Control)에 의해 전류제어 그리고 ANN을 이용하여 속도추정을 수행한다. 제시한 제어 알고리즘은 FAD MFC및 ANN 제어기를 사용하여 유도전동기 드라이브 시스템에 적용한다. 제시한 제어기의 성능은 유도전동기의 파라미터를 사용하여 다양한 동작조건에서 해석으로 평가한다. 또한, 본 논문은 제어기의 효용성을 입증하기 위하여 해석결과를 제시한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.385-388
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• 2001

In this paper, the gearless traction machine drive system using a permanent-maget motor for high-speed elevators is addressed. This application of permanent-magnet motor to the elevator traction machine enables several improvements including higher efficiency, better ride comfort, smaller size and weight, and so on. PWM boost converter is also adopted so that DC-link voltage regulation, hi-directional power flow, and controllable power factor with reduced input current harmonics are possible. To increase reliability and performance, the control board, which can include the car and group controller as well as PWM converter and inverter controller, is designed based on TMS320VC33 DSP The simulator system for high-speed elevators has been developed so that the drive system of high-speed elevator can be tested without my limitation on ride distance and the load condition. Some experimental results are given to verify the effectiveness of the developed system.