• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.372-374
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• 1999

AC 전동기는 전기각 주파수에 비례하는 간섭항을 가지고 있어 d-q축의 전류응답이 서로 간섭을 일으키게 된다. 이런 간섭현상은 특히 고속운전에서 크게 나타나며, 이로 인해서 토오크 응답이 영향을 받게 되어 고성능을 요하는 적용 범위에서는 문제가 될 수 있다. 이를 해결하기 위해서 지금까지 몇 가지 방법이 제안되어 왔다. 본 논문에서는 이러한 방법들에 대해서 비간섭 제어 성능을 비교하고 파라미터 변화에 따른 영향을 분석한다. 분석된 결과는 실험을 통해서 얻어진 결과와 일치함이 보여진다.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.411-411
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• 2000

본 논문에서는 새로운 형태의 정밀위치제어용 3자유도 매니플레이터를 제안하고, 기구학 해석을 수행하며, FEM과 수치해석적인 방법을 비교하여 메카니즘에 대한 모델링 방법이 크게 틀리지 않음을 확인 하고자 한다. 회전관절과 구형관절은 비구동관절로써 미소움직임이 가능하도록 하나의 모듈로 이루어진 flexure hinge들로 만들어진다. 따라서, 비구동관절에 대한 강성해석을 수행하며 구동관절의 토오크 벡터를 비구동관절의 강성과 변위로 표현하여 액추에이터의 구동용량을 결정한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.9-16
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• 2011

Research on ISA(Integrated Starter/Alternator) receives wide attention as system voltage is increased to 42V Based on requirement of starter and alternator for the conventional vehicle, system requirement and specification are determined. Also to control proposed system, suitable control methods are proposed. Main control issues with ISA are whether torque assist is required and if so how much torque is needed. In this paper, vehicle performance with various control methods and capacity are simulated and simulation results are analyzed. Vehicle performance is analyzed with vehicle simulator. For the simulation, suitable ISA model is also developed.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.296-299
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• 2003

The conventional DTC strategy provides a fast torque response even though it has very simple scheme consisted with only two hysteresis band comparators and a switching table for torque and flux control. Drawbacks of the conventional DTC are relatively high torque ripple at low speed and variation of the switching frequency according to motor speed. In this paper, the new direct torque control(DTC) schemes are proposed. Those schemes are based on the torque slope and enable to reduce the torque ripple and maintain the switching frequency constantly.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.3
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• pp.299-306
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• 2001

It is one of the most effective methods for performance improvement of electric railway vehicle to make better the wheel-rail adhesion character. In order to research adhesion character, adhesion system is developed. The experiment system makes it possible to change various adhesion parameters. This paper studied to restrain vibration of slip speed using torque control gy means of slip speed.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.634-637
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• 2010

본 논문은 미세구조의 마이크로 액추에이터의 구동해석을 위한 결과로써 3차원 유한요소해석(Finite Element Analysis, FEA)을 이용하여 수행하였다. 마이크로머신과 같은 미소구조물을 해석하는 경우, 컴퓨터의 메인 프로세스에 비해 프리프로세서(pre-processor)의 비중이 높아지고 있어 그 효율화가 가장 중요하다. 수작업에 의존해야 했던 지난날의 요소분할법 기술은 최근에 들어 여러 연구자들에 의해 개발되고 있다. 특히, 복합현상을 다루는 정전 액추에이터에 직접적인 적용에 다소 어려움이 있는데 3차원적인 수치 및 실험평가는 실용적인 문제에서 비추어 볼 때 매우 중요하다. 따라서 본 논문에서는 센서로서의 역할을 하는 마이크로 정전 액추에이터의 기본설계를 위한 토대를 구축하고자 3차원적인 FEA 시뮬레이션을 수행하여 미세 회전운동을 분석하였다. 그 결과 설계된 모델에서 먼저 자중해석과 Mode 해석에서 기준치를 모두 만족하였다. 또한 설계된 액추에이터의 형상에 따른 회전자의 변형해석을 수행하여 시작토오크와 탄성한계까지의 위치제어에 필요한 회전각을 구하였으며, 정전장 해석을 통하여 시작토오크는 전압 $V^2$에 비례함을 알 수 있었다.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1206-1208
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• 2001

Direct torque control(DTC) of AC motor has the fast torque and flux dynamic responses even though it has very simple scheme to implement. DTC is also very simple in its implementation because it needs only two hysteresis comparators and switching vector table for both flux and torque control. The amplitude of hysteresis band greatly influences on the drive performance such as flux and torque ripple, switching frequency and current harmonics. Therefore, authors analysis flux and torque hysteresis bands is suggested considering switching frequency and harmonic distortion of currents.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.1
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• pp.94-100
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• 1998

Microstep characteristics largely depends on the variation of friction force induced by the geometric accuracy of ballscrew, guide rail and the control characteristics of servo unit. In this paper, for improving the microstep characteristics of hydrostatic table with ballscrew, microstep resolution according to the control mode of servo amplifier and response characteristic by the variation of integral gain are tested and compared. Relationship between micro motion behavior of hydrostatic table and the output torque is also tested for acquiring the effective variables on control characteristics. From the results. it is confirmed that the torque control mode has a advantage in microstep resolution, and more stable than velocity control mode in low feed rate, and by the increase of integral gain in the elastic motion realm, response characteristics can be improved.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.212-216
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• 1998

For a Switched Reluctance Motor(SRM) drive, the important things are 1) reducing torque ripple, 2) improving efficiency, 3) sensorless speed control, 4) accurate position. The position information impotant for the efficiency and smoothness drives. Since SRMs characteristics are nonlinear. It is difficult to estimated phase current in saturation region. This paper describes a method for indirect sensing of the rotor position in SRM which use both voltage and current. The method obtains rotor position by using unconducting phase. The information about the rotor position is achieved by differentiating the unconducting phase current or the voltage gradient. And then, this paper presents a torque control with indirect rotor position detection methods. This torque control is achieved by developing a detailed nonlinear model of the motor.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1135-1137
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• 2003

The conventional DTC strategy provides a fast torque response even though it has very simple scheme consisted with only two hysteresis band comparators and a switching table for torque and flux control. Drawbacks of the conventional BTC are relatively high torque ripple at low speed and variation of the switching frequency according to motor speed. In this paper, the new direct torque control(BTC) schemes are proposed. Those schemes are based on the torque slope and and flux to reduce the torque ripple.