• Journal of IKEEE
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• v.25 no.2
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• pp.381-387
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• 2021

As Head-Mounted Displays(HMDs), which are mainly used to maximize realism in games and videos, have experienced increased demand and expanded scope of use in education and training, there is growing interest in methods to enhance the performance of conventional HMDs. In this study, a methodology to utilize Carbon NanoTubes(CNTs) to improve the performance of gate drivers that send control signals to each pixel circuit of the HMD is discussed. This paper proposes a new circuit design method that replaces the transistors constituting the buffer part of the conventional gate driver with transistors incorporating CNTs and compare the performance of the suggested gate drive with that of a gate driver comprising only conventional transistors via simulations. According to the simulation results, by including CNTs in the gate driver, the output voltage can be increased by approximately 0.3V compared to the conventional gate driver high voltage(1.1V) at a speed of 12.5 GHz and the gate width also can be reduced by up to 20 times.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.316-320
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• 1995

This paper proposes two base/gate drive suppression methods of NPC inverters. The first is the output current polarity detection type, which can be regarded as an extension of Joshi and Bose's method for ordinary inverters. But this method has difficulties in implementation. The second is the output voltage polarity detection type, which is easier to implement than the former. The base/gate drive suppression methods have the merit that it does not have the dead time problem, reduces the power loss of the driving circuit, and others.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.52-56
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• 2014

In this paper, a high-efficiency power amplifier is implemented using a gate and drain bias control circuit for WPT (Wireless Power Transmission). This control circuit has been employed to improve the PAE (Power Added Efficiency). The gate and drain bias control circuits consists of a directional coupler, power detector, and operation amplifier. A high gain two-stage amplifier using a drive amplifier is used for the low input stage of the power amplifier. The proposed power amplifier that uses a gate and drain bias control circuit can have high efficiency at a low and high power level. The PAE has been improved up to 80.5%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.88-99
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• 2007

In this paper, a novel new pulse power generator based on IGBT stacks is proposed for pulse power application. Because it can generate up to 60kV pulse output voltage without any step- up transformer or pulse forming network, it has advantages of fast rising time, easiness of pulse width variation and rectangular pulse shape. Proposed scheme consists of series connected 9 power stages to generate maximum 60kV output pulse and one series resonant power inverter to charge DC capacitor voltage. Each power stages are configured as 8 series connected power cells and each power cell generates up to 850VDC pulse. Finally pulse output voltage is applied using total 72 series connected IGBTs. To reduce component for gate power supply, a simple and robust gate drive circuit is proposed. For gating signal synchronization, full bridge invertor and pulse transformer generates on-off signals of IGBT gating with gate power simultaneously and it has very good characteristics of short circuit protection.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.746-748
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• 1993

To overcome the problem of the diode reverse recovery in high switching frequency inverter, a new gate drive scheme is proposed for IGBT in this paper. Using this circuit, the reverse recovery current can be controlled and faster switching time can be achieved for hard switching inverter. The over-current protection method, which is suitable for the proposed gate driver, is also presented. The operation of the proposed circuit is investigated and its usefulness is verified through the experimental results.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.148-150
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• 1993

The IGBT(Insulated Gate Bipolar Transistor) is a power semiconductor device that has gained acceptance among power electronic circuit design engineers for motor drive and Power converter applications. The device-circuit interaction of power insulated gate bipolar transistor for a series-inductor load, both with and without a snubber are, simulated. An analytical model for the transient operation of the IGBT is used in conjunction with the load circuit state equations for the simulations.

• Journal of Power Electronics
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• v.16 no.2
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• pp.553-563
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• 2016

This paper presents a digital hardware implementation of a real-time simulator for a multiphase drive using a field-programmable gate array (FPGA) device. The simulator was developed with a modular and hierarchical design using very high-speed integrated circuit hardware description language (VHDL). Hence, this simulator is flexible and portable. A state-space representation model suitable for FPGA implementations was proposed for a dual three-phase induction machine (DTPIM). The simulator also models a two-level 12-pulse insulated-gate bipolar transistor (IGBT)-based voltage-source converter (VSC), a pulse-width modulation scheme, and a measurement system. Real-time simulation outputs (stator currents and rotor speed) were validated under steady-state and transient conditions using as reference an experimental test bench based on a DTPIM with 15 kW-rated power. The accuracy of the proposed digital hardware implementation was evaluated according to the simulation and experimental results. Finally, statistical performance parameters were provided to analyze the efficiency of the proposed DTPIM hardware implementation method.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.232-234
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• 2002

Due to development of power electronics technology, power conversion system are tend to small size, easy to use and light weight. Especially motor control system have increased concerns and interests about IPM(Intelligent Power Module) inverter, which contains protection circuit, drive circuit and power devices. So, we manufactured 3-phase inverter using DIP-IPM(Dual in-line package IPM) PS21245- E(1.5 Kw) made by MITSUBISHI Electric. Some of these features include -HVIC to Provide level shifting and gate drive for high-side IGBTs. The interface circuit between pwm controller and DIP-IPM can made by direct connection. In order to validate dynamic performance of the proposed system, the actual experiment worked out at wide speed range. The developed system is shown as a good dynamic characteristics.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1304-1306
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• 1996

A regenerative signal amplifying gate driver of self-excited electronic ballast is presented. It can be used for high pressure sodium (HPS) lamp without auxiliary external ignitor. Since the HPS lamp requires very high ignition voltage at start up, the resonant frequency of the circuit must be increased to obtain high voltage oscillations in spite of relatively small resonant current. The presented gate driver amplifies the current of gate drive transformer and raises the gate-source voltage Quickly to turn on the MOSFET switches. Hence, the resonant frequency can be increased more than 100kHz. The HPS lamp used in the simulation and experiment has the rating of 400W input power at 220V input ac voltage source. The experiments show that the resonant frequency is above 150kHz at start up.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05b
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• pp.22-25
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• 2001

A thyristor switch circuit for capacitor discharge application, of which the equivalent circuit includes a resistor between cathode and gate of a reverse-conducting thyristor and an avalanche diode anti-parallel between its anode and gate to set thyristor tum-on voltage, is monolithically integrated by planar process with AVE double-implantation method. To ensure a lower breakdown voltage of the avalanche diode for thyristor tum-on than the break-over voltage of the thyristor, $p^+$ wells on thyristor p base layer are made by boron implantation/drive-in for a steeper doping profile with higher concentrations while rest p layers of thyristor and free-wheeling diode parts are formed with Al implantation/drive-in for a doping profile of lower steepness. The free-wheeling diode part is isolated from the thyristor part by formation of separated p-well emitter for suppressing commutation between them, which is achieved during the formation of thyristor p-base layer.