• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.312-317
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• 1996

This paper compares the output voltage control strategies of three-phase PWM inverter for uninterruptible power supply. The feedforward control, feedforward/feedback control, and decoupled feedback control in both the synchronous reference frame and the stationary reference frame are examined. In particular, it is shown that the response of the decoupled feedback controller in the synchronous reference frame can be improved by pole-zero cancellation method. It is also shown that the pole-zero cancellation method reduces to the deadbeat control, when it is implemented with digital controller.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.666-669
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• 1991

This paper deals with the robustness of a direct adaptive pole-placement control algorithm for continuous time plants with unmodeled dynamics. In this paper, least squares method is used for controller parameter adaptation and covariance matrix update equation is modified by normalizing signal to guarantee the boundedness of all signals in the closed loop system. In the proposed algorithm, no a priori knowledge is required and it is shown that persistence of excitation condition is required to ensure the stability of the closed loop system.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.179-180
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• 2008

본 논문에서는 극배치(pole placement) 제어 시스템의 상태들에 의해서 훈련된 신경 회로망(Neural Network)을 기반으로 새로운 슬라이딩 평면의 설계 기법을 제안한다 훈련된 데이더를 가진 신경 회로망은 배치 제어의 성능을 가지며 새로운 슬라이딩 평면을 설계하는데 사용되어 진다. 그 결과 시스템의 파라미터 불확실성이 존재하더라도 제안된 슬라이딩 평면으로서 슬라이딩 모드 제어의 강인성이 신경회로망을 통한 극배치제어의 성능에 추가되는 것이 가능하다.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.31-33
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• 2007

In this paper, a simple digital control scheme for the single/parallel module buck converters is proposed using a digital state feedback control method. The discrete state feedback controller structure for the robust tracking control is derived by using the error state. The proposed control system can precisely achieve the interleaved current sharing and the output regulation, and can achieve the systematical controller design for a given converter specification using the pole placement technique. For a design example, the single module buck converter is simulated using the MATLAB Simulink software and two 100W parallel module buck converters with a TMS320F2812 DSP is implemented.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.139-141
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• 2008

This paper presents a PID controller and PI-PI dual loop controller for a single-phase inverter. The control parameters of conventional controllers are very difficult to make. But parameters of controllers based on pole-assignment are easy to make. Simulation results are presented for the system under R-L load, no load and change reference voltage.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.496-500
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• 2003

In This paper, a pole-zero optimized design method for multi-layed planar interdigital stripeline linear group delay bandpass filter with tap input port is presented. As a design example, a four-pole group delay filter with center frequency of 2.14GHz, bandwidth of 160MHz, and group delay variation of ${\pm}0.1nS$ for LTCC technology or multilayerd PCB technology is designed. In the design process, as well the whole structure is not necessary to be simulated, and within three times of optimizing process we have good result as well. This design method could be useful for controlling error correction of manufacturing process as well as design stage.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.701-702
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• 2008

An adaptive response surface method with Latin Hypercube sampling strategy is employed to optimize a magnet pole shape of large scale BLDC motor to minimize the cogging torque. The proposed algorithm consists of the multi-objective Pareto optimization and (1+${\lambda}$) evolution strategy to find the global optimal points with relatively fewer sampling data. In the adaptive RSM, an adaptive sampling point insertion method is developed utilizing the design sensitivities computed by using finite element method to get a reasonable response surface with a relatively small number of sampling points. The developed algorithm is applied to the shape optimization of PM poles for 6 MW BLDC motor, and the cogging torque is reduced to 19% of the initial one.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.3
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• pp.429-436
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• 2003

The electrical discharge machining(EDM) with Si electrode instead of Gr or Cu electrode. made enormous effects on the surface. machining time, anti-caustic workpiece surface and so on In this paper. we experimented on the inter-role distance during discharge the electrical phenomenon of inter-pole, the distribution of discharge point. the distribution of off load time. etc., using Si electrode Cu electrode and Gr electrode under the same machining condition. As a result of a large quantity generated exclusive powders. the performance of the EDM using Si electrode. compared with EDM using others. is improved. We show that the quantities of those make far pole-gap discharge and discharge scatter under stable machining status possible.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.2
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• pp.84-89
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• 2003

The finite element method (FEM) is typically used in the process of motor design. However, the FEM requires computation time, Therefore, decreasing the number of FEM simulations may also decrease the simulation cost. Several optimal design methods overcoming this problem have been recently studied. This paper investigates the optimal design of the magnet pole of a BLDC motor through reducing simulation cost. The optimization minimizes the magnet volume and limits the average and cogging torques to certain values. In this paper, the response surface methodology and Taguchi's table for reducing the number of FEM simulations are used to approximate two constraints. The optimization result shows that the presented strategy is satisfactorily performed.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.43-46
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• 1990

A general scheme for a discrete adaptive observer having exponetial weighting properties is presented for a single-input single-output linear system. In this scheme, all the past measurement data are weighted esponetially both with the weighting factor and the stable matrix F. This observer is then implemented in the design of an indirect adaptive pole placement contoller. To increase nemerical stability in getting the controller parameter, a recusive algorithm is introduced. It is shown that the overall control scheme is globally stable with the persistent excition