HID 램프 안정기 특성에 관한 연구

김이국 경일대학교 산업기술연구소 1994 産業技術硏究所 論文集 Vol.4 No.-

This paper propose high frequency resonant inverter for the high intensity discharge(HID) lamp drive. Its operation and characteristics are described, then the method we select the frequency to decrease switching loss and to maximize output power is presented by the result of simulation.

시간지연을 가지는 전자광학 추적 시스템의 표적 추적 성능 개선 방법

金利國,崔演鎬,馬鎭碩 慶一大學校 1999 論文集 Vol.16 No.2

In this paper, we present a tracking accuracy enhancement method by compensating the time delay of the video tracker in an EOTS. The proposed method has two functional parts, which can cope with the time delay of LOS and maneuvering target informations by Smith predictor and Kalman filter. So it can dramatically reduce the tracking error over conventional PI control or Smith predictor control. To verify the proposed method, various and extensive simulation and experimental results are given.

단석 사고시 전압변화에 관한 연구

金利國 慶一大學校 1998 論文集 Vol.15 No.1

This paper represents the change of voltage nd current at one line open fault of power system. As the results of computer simulation, the secondary voltage change of ideal transformer and that of commercial transformer are similar to each other at inductive and no load. But at motor load, the voltage does not change for a short time, which is different from ideal transformer.

방전 램프용 고주파 공진형 인버터의 특성 해석

배영호,김인식,김이국 경일대학교 산업기술연구소 1999 産業技術硏究所 論文集 Vol.6 No.-

This paper describes to electronic ballast for high insensitive discharge lamp(HID) which has been widely used to illuminating and electrical installation apparatus as a lighting system. In generally, Ballast for HID lamp have been dominated by Magnetic leakage transformer. Since the weight of such ballast are relatively heavy, those distort line voltage and current waveforms. Also, their power factor decreases. Therefore, this paper proposes electronic ballast using conventional Half-bridge Inverter with resonant circuit. From the analysis of circuit configuration for the proposed circuit and the computer simulation results, the current and voltage of the load can be controlled properly in accordance with switching model.

형광 방전등을 위한 전자식 안정기 해석

金利國 慶一大學校 1999 論文集 Vol.16 No.5

Fluorescent lamp has been widely used to illuminating and electrical installaion apparatus as a lighting system. But, the conventional Ballast for fluorescent lamp have been dominated by Magnetic leakage transformer. Since the weight of such ballst are relatively heavy, also, their power factor decreases. Therefore, this paper proposes electronic ballast using Inverter in combination with resonant circuit and MOSFET. From the computer simulation results, the current of the lamp can be controlled properly in accordance with resonant operations.

HET硬化劑에 의한 Epoxy樹脂의 硬化條件에 관한 硏究 : 積層材料와 複合材料의 Matrix 中心으로 Focusing in the Matrix of the compound materials and laminated materials

金利國 慶一大學校 1990 論文集 Vol.6 No.1

In this paper, the electrical and thermal properties of the heat resisting epoxy resin mixed with the hardener HET were investigated as the curing condition was varied. The experimental results were as follows. 1) The optimal ratio of the hardener HET was 100 phr, and then the interior reaction temperature was 120℃. The optimal sample was obtained when it was pre-cured for 2 hours at 100℃. Above results are closely related with the coupled state of interior morecule and three-dimensional cross-linking of thermo-setting epoxy resin. 2) The optimal post-curing temperature was 180℃ for cross-linking the unreacted radicals. 3) The optimal post-curing time was between 20 and 40 hours for the best electrical and thermal properties. 4) The maximum a. c dielectic strength was 26[KV/mm] and the deformation temperature was between 175 and 180℃.

BUCK-BOOST 제어기법에 의한 단상 AC/AC 컨버터의 해석

裵英鎬,金利國 慶一大學校 1998 論文集 Vol.15 No.1

This paper describes to control system for AC to AC converter which has been widely used to power source in industrial factory and electric machine for Domestic. Up to now, AC to AC power converters have been dominated by line-commutated phase-controled rectifiers. Since harmonics of input line current in such converters are relatively high, those distort line voltage waveform and their power factor decreases. Therefore, this paper proposes direct AC to AC converter using cinventional buck-boost type PWM control method. It provides near sinusoidal input current with unity power factor and a low output voltage ripple with high frequency switching signals for the converter.

HET 硬化劑에 依한 Epoxy 樹脂의 絶緣破壞 特性에 관한 硏究

金利國 경일대학교 산업기술연구소 1991 産業技術硏究所 論文集 Vol.1 No.-

In this paper, the electrical break down characteristics of the heat resisting epoxy resin mixed with the hardner HET were inverstigated as the curing condition make a change. The experimental results were as follows. 1) The optimal ratio of the hardner HET was 100phr, and then the interior reaction temperature was 120℃. The optimal sample was obtained when it was pre-cured for 2 hours at 100℃, Above results are closely related with the coupled state of interior morecule and three-dimensional cross-linking of thermo-setting epoxy resin. 2) The optimal post-curing time was 30hours for the best electrical and thermal properties. 3) The optimal post-curing temperature was 180℃ for cross-linking the unreacted ridicals. 4) When the same thickness of spaciments are applied by AC(60Hz) voltages. breakdown voltages (V??) have the highest value with Sphere-Sphere electrodes and have the lowest value with Needle-plane electrodes. 5) When Needle-Plane electrodes are applied by DC voltages. V?? is loweras Needle electrode has positive polarity than negative polarity. 6) V?? of DC is much higher than that of AV. When the same thickness of Spacimens are applied by AC(60Hz) and DC voltage with Needle-Plane electrodes.

단상능동전력필터를 위한 저가형 제어기 설계

金利國,郭尙信,金佑鉉 慶一大學校 1999 論文集 Vol.16 No.2

A new control method for a single-phase active power filter is proposed. The proposed method is based on a load current estimation using a DC capacitor voltage of active power filter without sensing nonlinear load current. Compared with a conventional method sensing the load current and DC capacitor voltage together, because the proposed method need not the load current sensor, it has many advantages, easy installation, low cost, small size with no performance detriment. Sample-hold technique and proportional control are used to control the DC capacitor voltage. So, because no delay elements by LPE or PI control in the conventional method are used, the transient response is fast. Operation of a single-phase active power filter which consist of eight mode is analyzed according to utility voltage, compensation current and switch state. And the performance of active power filter designed by the proposed method is verified by experiment.

12 Pulse 컨버터의 Notch법에 의한 출력측 저고조파의 제거

金利國,裵英鎬,鄭泰和 慶一大學校 1994 論文集 Vol.10 No.1

Line-current harmonics resulting from ac to dc power conversion interferr with power system operation and reduce power factor, hence resulting in increasing power source unnecessarily. This study describes a 12 pulse phase-controlled converter eliminating low frequency harmonics in the output by inserting notches. Notch points are calculated by Newton-Raphson method. The impacts of the choppings on ac and dc sides are analysed in the steady state. Potential applications of the study are dc motor controls, high power dc power supplies for telecommunications, static var compensators and HVDC.