• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.3
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• pp.214-222
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• 2015

The superiority of gallium nitride FET (GaN FET) over silicon MOSFET is examined in this paper. One of the outstanding features of GaN FET is low reverse-recovery charge, which enables continuous conduction mode operation of totem-pole bridgeless boost power factor correction (PFC) circuit. Among many bridgeless topologies, totem-pole bridgeless shows high efficiency and low conducted electromagnetic interference performance, with low cost and simple control scheme. The operation principle, control scheme, and circuit implementation of the proposed topology are provided. The converter is driven in two-module interleaved topology to operate at a power level of 5.5 kW, whereas phase-shedding control is adopted for light load efficiency improvement. Negative bias circuit is used in gate drivers to avoid the shoot-through induced by high speed switching. The superiority of GaN FET is verified by constructing a 5.5 kW prototype of two-module interleaved totem-pole bridgeless boost PFC converter. The experiment results show the highest efficiency of 98.7% at 1.6 kW load and an efficiency of 97.7% at the rated load.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.5
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• pp.193-199
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• 1984

This paper presents a direct adaptive pole placement control scheme which is applicable to discretetime non-minimum phase systems. It is proved that by this scheme the poles can be placed at the desired locations and the overall state vector of the system is uniformly bounded if the reference input is sufficiently rich, and also proved that in case of insufficiently rich reference input the overall system can still be stabilized though the poles may not be placed exactly at the desired locations. The effectiveness of this scheme is verified by digital computer simulations.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.10
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• pp.427-437
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• 1986

Identification of the plants is not easy task especially in the fields of process control. From this point of view, Kitamori developed a method of control system design based on partial knowledge about controlled processes. However, it is difficult to control the oscillatory plant by kitamori's method. In this paper, we develope a method of partial model matching control system design, which have desirable pole-placements in order to improve the above defects. Design examples are given to illustrate the effectiveness of the method.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.2
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• pp.127-132
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• 2002

In this paper, the new claw pole type linear stepping motor(CPLSM) is proposed. And the magnetic equivalent circuit of CPLSM is derived by the structure of the CPLSM. The design parameter and the magnetic flux density of CPLSM are performed with three-dimensional finite element method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.295-298
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• 2001

This paper presents mechanical properties and weatherability of FRP pole used for a distribution line about high strength and good insulation properties. The experiment strength obtained in cantilever beam test are comparable to ES standards. The environmental factors, such as elevated temperatures, high humidity, and corrosive fluids, and ultraviolet(UV) rays, influence on the performance of Polymeric matrix composite.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.169-171
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• 2009

In recent years, environmental concerns have been raised on the use of poorly biodegradable fluids in electrical apparatus in regions where spills from leaks and equipment failure could contaminate the surroundings. For development of the environmental-friendly pole transformer using vegetable oil, we discussed the insulation construction of the transformer and the dielectric characteristics of the Nomex insulation paper in vegetable oil. Based on the experimental data, the insulation of the transformer is designed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.339-342
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• 1998

A high performance, high-dielectric stripline filter has been developed. The filter consists of planar resonators and its structure is made of high permittivity multilayer ceramic. The performance is distinctive with its attenuation pole. An equivalent lumped circuit is derived to explain the behavior of the attenuation pole quantitatively. A precise design procedure is also described.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.12
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• pp.472-484
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• 1985

A design of robust voltage controller for high speed excitation of synchronous machine was carried out by pole assignment techniques. An affine map from characteristic polynomial coefficients to feedback parameters is formulated in order to place the system eigen values in the desired region. The feedback parameters determined from linearized model are tested on nonlinear model subjecting it to small disturbances and system faults to show the effectiveness of the controller designed by the proposed technique. The results obtained indicate that the controller presented improves the dynamic stability and system performances of conventionally controlled synchronous machine significantly.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.9
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• pp.655-662
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• 1988

An adaptive control scheme has been recognized as an effective approach for a robot manipulator to track a deired trajectory in spite of the presence of nonlinearies and parameter uncertainties in robot dynamic models. In this paper, an adaptive control scheme for a robot manipulator is proposed to design the self-tuning controller which controls the extended linearized perturbaton model via the pole placement, and this control. The feasibility of the controller is demonstrated by the simulation about position control of a three-link manipulator with payload and parameter uncertainty.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.2
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• pp.183-191
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• 1991

This paper develops a pole-zero assignment self-tuning regulator utilizing the method of a neural network in the plant parameter estimation. An approach to parameter estimation of the plant with a Hopfield neural network model is proposed, and the control characteristics of the plant are evaluated by means of a simulation for a second-order linear time invariant plant. The results obtained with those of Exponentially Weighted Recursive Least Squares(EWRLS) method are also shown.