• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1031-1032
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• 2007

In order to reduce the cogging torque, by predicting the variation of the cogging torque according to pole arc/pitch ratio by analytical and FE methods, pole arc/pitch ratio which makes the cogging torque minimum are determined. And then, the measurements of cogging torque for permanent magnet generators with determined pole arc/pitch ratio are presented. The reasons for the error between predicted and measured value are discussed fully in terms of the shape of permanent magnet. Finally, by confirming that predicted results for cogging torque according to pole arc/pitch ratio and skew are shown in good agreement with those obtained from measured one, the validation of analysis results is confirmed.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.118-120
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• 2006

This paper proposes a new stator pole shape having non-uniform air-gap in order to minimize the undesirable torque ripple of switched reluctance motor(SRM). Through numerical analysis using finite element method(FEM) and optimization, the proposed pole-shape-optimized stator is proven to give reduced torque ripple.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.916-917
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• 2011

본 논문에서는 WPM의 기동시 감자된 영구자석을 착자시키는 exciter pole의 최적설계에 대해 다룬다. 영구자석형 동기전동기의 성능을 결정짓는 자석의 잔류자속밀도를 최대로 만들기 위하여 반응표면법을 이용하여 exciter를 설계하였다. 목적함수는 영구자석 중심에서 의 자계의 세기이며 정밀도를 위하여 유한요소법을 통해 결과를 확인하였다.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.62-65
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• 1989

Optimizing transient response for both tracking reference signals and disturbance rejection is determined by the poles and zeros of the transfer function. Thus, optimal pole assignment and how should weighting matrix for the performance index be chosen is very important to achieve optimum transient response. This paper focus its attention on the choosing and analysis of weighting matrix for optimum pole assignment. Optimum pole assignment is defined for linear time-invariant continuous systems.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.146-150
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• 1989

In the pole assignment strategy, the closed loop poles are placed at prespecified locations. The amount of control effort required is to some extent proportional to the distance of the proposed closed loop locations of the poles from their open loop locations. The poor choice of closed loop locations may result in Large control effort and it may nuke the system unstable. To overcome this problem, pole shift control strategy is described in this paper. The validity of the proposed control strategy is assured through some simulations.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.407-410
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• 1989

Optimizing transient response for both tracking reference signals and disturbance rejection is determined by the poles and zeros of the transfer function. Thus, optimal pole assignment and how should weighting matrix for the performance index be chosen is very important to achieve optimum transient response. This paper focus its attention on the choosing and analysis of weighting matrix for optimum pole assignment. Optimum pole assignment is defined for linear time-invariant continuous systems.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.589-591
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• 1999

In this paper, we consider the robust pole assignment for linear system with time-varying uncertainty. The considered uncertainty is an unstructured uncertainty. Based on Lyapunov stability and linear matrix inequality technique, we present a condition that guarantees the robust pole assignment inside a circular disk and the robust stability of uncertain linear systems. Finally, we show the usefulness of our results by an example.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.82-84
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• 2009

최근 널리 사용되고 있는 BLDC Motor는 코깅 토크 문제점을 가지고 있다. 본 연구에서는 4극 24슬롯 BLDC Motor를 Flux 2D로 시뮬레이션 하였고, 문제점을 파악하여 Magnet Pole Cover를 이용한 모터를 설계하고 분석하였다.

• International Journal of Control, Automation, and Systems
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• v.3 no.3
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• pp.430-443
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• 2005

A general construction algorithm of the Grassmann space parameters in linear systems - so-called, the Plucker matrix, 'L' in m-input, p-output, n-th order static output feedback systems and the Plucker matrix, $'L^{aug}'$ in augmented (m+d)-input, (p+d)-output, (n+d)-th order static output feedback systems - is presented for numerical checking of necessary conditions of complete static and complete minimum d-th order dynamic output feedback pole-assignments, respectively, and also for discernment of deterministic computation condition of their pole-assignable real solutions. Through the construction of L, it is shown that certain generically pole-assignable strictly proper mp > n system is actually none pole-assignable over any (real and complex) output feedbacks, by intrinsic rank deficiency of some submatrix of L. And it is also concretely illustrated that this none pole-assignable mp > n system by static output feedback can be arbitrary pole-assignable system via minimum d-th order dynamic output feedback, which is constructed by deterministic computation under full­rank of some submatrix of $L^{aug}$.

• Journal of IKEEE
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• v.22 no.3
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• pp.759-766
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• 2018

This paper presents a high-speed axial-flux machine which utilizes the idea of sinusoidal shaped pole combined with a consequent iron-pole. The target of the proposed machine is the cost reduction of the relatively expensive Samarium-Cobalt (SmCo) permanent magnet (PM) material and the torque per PM volume improvement by using sinusoidal consequent-pole rotor. The effectiveness of the proposed machine is validated by comparing it with conventional consequent-pole and with conventional PM machines using 3-D finite element method (FEM) simulations. The comparison and analysis is done in terms of back electro-motive force (back-EMF) harmonic contents, torque per PM volume and torque ripple characteristics. The simulation results show that the proposed machine is suitable and cost-effective for high-speed and high torque per PM volume applications. Furthermore, due to the consequent pole, the magnetic flux saturation and the overload current torque-capability are also presented and discussed in the paper.