• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.9
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• pp.422-430
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• 2005

This paper describes experimental analysis of UPFC, which is composed of cascaded H-bridge modules and single-phase multi-winding transformers for isolation. The operational characteristic was analyzed through experimental works with a scaled model, and simulation results with PSCAD/EMTDC. The UPFC proposed in this paper can be directly connected to the transmission line without series injection transformers. It has flexibility to expand the operation voltage by increasing the number of H-bridge modules. The analysis results can be utilized to design the actual WFC system applicable for the transmission system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.399-403
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• 2005

In this paper, we analyze on the effect of RC filter to mitigate transient overvoltage on the high voltage induction motor fed by H-bridge cascaded 7-level inverter. The switching surge voltage becomes the major cause to occur the insulation failure by serious voltage stress in the stator winding of high voltage induction motor. The effect of switching surge appears more serious in high voltage induction motor than low voltage induction motor. Consequently, we demonstrated that the RC filter connected to the motor terminals greatly reduces the transient voltage stress md ringing. The results of simulation show the suppression of transient overvoltage at the motor end of a long cable. using EMTP

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1993.10a
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• pp.25-32
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• 1993

The design theory of a generalized n-way power divider with arbitrary dividing rations for CATV and/or MATV systems which consists of ideal multi-winding transformers and resistors only was presented. Since the circuit elements have not frequency dependence the proposed power divider is to be of exetremely broad band-width. Furthermore as a result of computer simulation the frequency characteristics are very good in spite of errors of turn numbers and hence it was confirmed that the proposed design theory is valid.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.103-107
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• 2001

This study is simulation about buckling behavior under axial compression which is cylindrical panel laminated USN125 and USN150 made by various winding angle. And also this study compare with linear and nonlinear FDEM theory, and FEM theory. To solve the objective function and the design variables, this study use the linear and nonlinear buckling theories or FDEM and nonlinear search optimum design method of ADS for minimum weight design on which stiffened laminated composite cylindrical panel with stiffener that R-type section.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.5
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• pp.761-769
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• 1994

VCB (Vacuum Circuit Breaker), with the strong arc extinction capability in switching the source of an induction motor, occurs the severe switching surge voltage which can cause the breakdown or the deterioration of motor insulation. Therefore, a method which reduces surge voltage across motor windings is necessary. So, it is analyzed that fast-rise-time surges resulting from VCB switching operations give rise to severe voltage stress on turn insulation. Additionally, the switching surge simulation algorithms using EMTP are developed, and C, R values of surge suppressor minimizing the steep-fronted stress in winding insulation surges are calculated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.387-390
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• 2000

The life of transformer is significantly dependent on the thermal behavior in windings. To analyse winding temperature rise, many transformer designer have calculated temperature distribution and hot spot point by finite element method(FEM). Recently, numerical analyses of transformer are studied for optimum design, that is electric field analysis, magnetic field, potential vibration, thermal distribution and thermal stress. Therefore design time and design cost are decreased by numerical analysis. In this paper, the temperature distribution and thermal stress analysis of 50kVA pole cast resin transformer for power distribution are investigated by FEM program. The temperature change according to load rates of transformer also have been investigated. We have carried out temperature rise test and test results are compared with simulation data.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.424-427
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• 2007

The LLC series resonant converter with a LLT (Inductor-Inductor-Transformer) transformer for PDP power supply is presented. LLT transformer used to combine the inductor and transformer into one unit has the increased leakage inductance in the primary and secondary due to the winding method and the use of the gaped core. The increased leakage inductance in the primary and secondary of LLT transformer can be impacted on the DC voltage gain characteristics of LLC series resonant converter. In this paper, DC gain characteristics and the experimental results of the LLC series resonant converter with a LLT transformer are verified on the Math-CAD simulation based on the theoretical analysis and the 600W experimental prototype.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1057-1059
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• 2003

This paper presents drive analysis of slotless air-cored PM linear synchronous motor using two-dimensional analytical method. In order to calculate dynamic characteristic, back-EMF and linkage flux are calculated by Permanent Magnet Field and also inductance are given by slotless winding current coil. PMLSM drive simulation is performed by PI control system.

• Transactions on Electrical and Electronic Materials
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• v.15 no.1
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• pp.1-6
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• 2014

Self-exciting electronic ballast, of small size, and low cost, and high power, with no stroboscopic effect, no noise, is widely used in the general lighting market. This paper describes the cause of high switching loss of self-exciting electronic ballast, based on its operational principle; then, to reduce the switch temperature and increase the reliability of the product, the drive circuit has been improved, to achieve soft-switching. The theory analysis, simulation and experimental result prove the feasibility and compatibility of this new method in practice. Finally, the design procedure and winding method of the self-exciting current transformer are introduced.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.32-35
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• 1996

This paper analyzes characteristics of PMLSM using 3 dimensional equivalent magnetic circuit network method (3-D EMC). PMLSM of which the effective electric-airgap is not only very large, but also the width is finite width lateral edges has much leakage flux. Therefore, 2-D analysis method cannot consider it so carefully that 3-D analysis method must required. 3-D EMC which will be used for analysis of PMLSM performs modeling of it including solt and teeth structure, uses the magnetic motive force of stator winding and permanent magnet as source. and calculates magnetic flux density and force considering nonlinear characteristics of materials. we verified analysis validity by comparing simulation results with expermental results.