• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.232-232
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• 2000

switched reluctance motors and drives are increasingly used in industrial applications due to their robust mechanical structure, low inertia and reduction in the rotor losses. As the motor speed increase turn on angle must be advanced to build up phase current. When C-dump converter is applied to switched reluctance motor, the capacitance of dump C has to have proper value. In this paper advance angle for a switched reluctance motor and capacitance of dump C are investigated. Then proper advance angle and the capacitance of dump-C are propose for the industrial low voltage SR motor.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.229-230
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• 2013

The conventional Three-Stage electronic ballast is stable, but Two-Stage electronic ballast has been researching because of efficiency. Three-Stage electronic ballast is consisted of PFC circuit, buck converter, and inverter circuit, but Two-stage is consisted of PFC circuit, Buck-Inverter full bridge circuit. The Buck-Inverter full bridge inverter consists of two half bridge inverters for low frequency switching, and high frequency switching. In the case of street lamp it is far from a lamp to a ballast, the conventional pulsed high voltage ignitor can not turn on the HID lamps because of reduction of ignition voltage. Therefore, it needs to do the research on a resonant ignition to turn on the HID lamps. Therefore, in the Two-Stage electronic ballast which has the resonant tank for ignition, the transient resonant current because of low frequency changing is analyzed, the novel algorithm is proposed to resuce the transient current.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.1
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• pp.1-8
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• 2014

The conventional Three-Stage electronic ballast is stable, but Two-Stage electronic ballast has been researching because of efficiency. Three-Stage electronic ballast is consisted of PFC circuit, buck converter, and inverter circuit, but Two-stage is consisted of PFC circuit, Buck-Inverter full bridge circuit. The Buck-Inverter full bridge inverter consists of two half bridge inverters for low frequency switching, and high frequency switching. In the case of street lamp it is far from a lamp to a ballast, the conventional pulsed high voltage ignitor can not turn on the HID lamps because of reduction of ignition voltage. Therefore, it needs to do the research on a resonant ignition to turn on the HID lamps. Therefore, in the Two-Stage electronic ballast which has the resonant tank for ignition, the transient resonant current because of low frequency changing is analyzed, the novel algorithm is proposed to resuce the transient current.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.357-360
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• 2003

In this paper, we designed 4.5kV/1.5kA IGCT devices. GCT thyristor has many superior characteristics compared with GTO thyristor, for examples; snubberless turn-off capability, short storage time, high turn-on capability, small turn-off gate charge and low total power loss of the application system containing device and peripheral parts such as anode reactor and snubber capacitance. In this paper we designed GCT thyristor devices, and analyzed static and dynamic characteristics of GCT thyristor depending on the minority carrier lifetime, n-base thickness and doping concentration of n-base region, respectively. Especially, turn-on and turn-off characteristics are very important characteristics for GCT thyristor devices. So, we considered above characteristic for design and analysis of GCT devices.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1664-1671
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• 2016

This paper presents the analysis of the gate-source voltage of the gallium nitride high electronic mobility transistor (GaN HEMT) in the half bridge structure focused on the mutual effects of two switching operation. Especially low side gate-source voltage is analyzed mathematically according to the high side switch turn-on and turn-off operation. Moreover, the influence of each gate resistance and parasitic component on the switching characteristic of other side switch is investigated, and the formula, simulation and experimental results are compared with theoretical data.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1853-1859
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• 2008

IGBT modules are designed for low loss, rugged for all environments and user friendly. Low on state saturation voltage with high switching speed is the primary concerns. In this paper selection of IGBT, module ratings and characteristics are discussed. The IGBT design topic of protection against over voltage and over current are covered. Emphasis on turn off switching, short circuit switching and necessary precautions are dealt. Selection of IGBT device, gate drive power, and its lay out considerations are covered in detail.

• Journal of IKEEE
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• v.21 no.2
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• pp.150-153
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• 2017

In this paper, a structure of GCNMOS based ESD protection circuit using floating-body technique is proposed. TCAD simulation of Synopsys was used to compare with the conventional GGNMOS and GCNMOS. Compared with the conventional GCNMOS, the proposed ESD protection circuit has lower trigger voltage and faster turn-on-time than conventional circuit because of the added NMOSFET. In the simulation result, the triggering voltage of the proposed ESD protection circuit is 4.86V and the turn-on-time is 1.47ns.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.63-66
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• 1996

An micro model for the power insulated Gate Bipolar Transistor(IGBT) is developed. The model consistently described the IGBT steady-state current-voltage characteristics and switching transient current and voltage waveform for all loading conditions. The model is based on the equivalent circuit of a MOSFET with supplies the base current to a low-gain, high-level injection, bipolar transistor with its base virtual contact at the collector and of the base. Model results are compared with measured turn-on and turn-off waveform for different drive, load, and feedback circuits.

• Journal of Power Electronics
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• v.18 no.3
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• pp.681-693
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• 2018

This paper proposes a soft-switching bidirectional dc-dc converter (BDC) with an auxiliary circuit. The proposed BDC can achieve the zero-voltage switching (ZVS) using an auxiliary circuit in the buck and boost operations. The auxiliary circuit supplies optimal energy for the ZVS operation of the main switches. The auxiliary circuit consists of a resonant inductor, a back-to-back switch and two capacitors. A small-sized resonant inductor and an auxiliary switch with a low-rated voltage can be used in the auxiliary circuit. Zero-current switching (ZCS) turn-on and turn-off of the auxiliary switches are possible. The proposed soft-switching scheme has a look-up table for optimal switching of the auxiliary switches. The proposed strategy properly adjusts the turn-on time of the auxiliary switch according to the load current. The proposed BDC is verified by the results of PSIM simulations and experiments on a 3-kW ZVS BDC system.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.312-319
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• 2012

The life of a power transformer is dependent on the life of the cellulose paper, which influenced by the hot spot temperature. Thus, the determination of the cellulose paper's life requires identifying the hot spot temperature of the transformer. Currently, however, the power transformer uses a heat run test is used in the factory test to measure top liquid temperature rise and average winding temperature rise, which is specified in its specification. The hot spot temperature is calculated by the winding resistance detected during the heat run test. This paper measures the hot spot temperature in the single-phase, 154kV, 15/20MVA power transformer by the optical fiber sensors and compares the value with the hot spot temperature calculated by the conventional heat run test in the factory test. To measure the hot spot temperature, ten optical fiber sensors were installed on both the high and low voltage winding; and the temperature distribution during the heat run test, three thermocouples were installed. The hot spot temperature shown in the heat run test was $92.6^{\circ}C$ on the low voltage winding. However, the hot spot temperature as measured by the optical fiber sensor appeared between turn 2 and turn 3 on the upper side of the low voltage winding, recording $105.9^{\circ}C$. The hot spot temperature of the low voltage winding as measured by the optical fiber sensor was $13.3^{\circ}C$ higher than the hot spot temperature calculated by the heat run test. Therefore, the hot spot factor (H) in IEC 60076-2 appeared to be 2.0.