• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.3
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• pp.115-124
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• 2002

This paper presents an active auxiliary edge-resonant DC link snubber with a ringing surge damper and a three-phase voltage source type zero voltage soft-switching inverter with the resonat snubber treated here for the AC servo motor driver applications. The operation of the active auxiliary edge-resonant DC link snubber circuit with PWM voltage is described, together with the practical design method to select its circuit parameters. The three-phase voltage source type soft-switching inverter with a single edge-resonant DC link snubber treated here is evaluated and discussed for the small-scale permanent magnet (PM) type-AC servo motor driver from an experimental point of view. In addition to these, the AC motor stator current and its motor speed response for the proposed three-phase soft-switching inverter employing Intelligent Power Module(IPM) based on IGBTS are compared with those of the conventional three-phase hard-switching inverter using IPM. The practical effectiveness of the three-phase soft-switching inverter-fed permanent magnet type AC motor speed tracking servo driver is proven on the basis of the common mode current in a novel type three-phase soft-switching inverter-fed AC motor side and the conductive noise on the mains terminal interface voltage as compared with those of the conventional three-phase hard-switching inverter-fed permanent magnet type AC servo motor driver for the speed tracking applications.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.247-250
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• 1999

This paper presents characteristics of neuron-MOSFET for the implementation of logic circuits such at the inverter and D/A converter. Neuron-MOSFETS were fabricated using double poly CMOS process. From the measured results, it was found that noise margin of the inverter was dependant on the coupling ratio and a complete D/A characteristics of the source follower could be obtained by using any input Sate as a control gate.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1063-1066
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• 1992

As the adjustable speed drives by means of PWM inverter are applied to a wider field of industries, the demands for lower acoustic noise caused by modulation is becoming more intense. With the development of high speed power semiconductor device such as the IGBTs, a higher carrier frequency can be adopted to increase the switching frequency to the supersonic range. The optimal magnitude of this signal is determined so that the sideband components near the carrier frequency are minimized

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.822-824
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• 2007

This paper investigated a gate driver circuit with amorphous silicon for mobile TFT-LCD. In the conventional circuit, the fluctuation of the off-state voltage causes the fluctuation of gate line voltages in the panel and then image quality becomes worse. Newly designed gate driver circuit with dynamic switching inverter and carry out signal reduce the fluctuation of the off-state voltage because dynamic switching inverter is holding the off-state voltage and the delay of carry signal is reduced. The simulation results show that the proposed a-Si:H gate driver has low noise and high stability compared with the conventional one.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.6
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• pp.546-555
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• 2001

In this paper filtering techniques to reduce the adverse effects of motor leads on high-frequency PWM inverter fed AC motor drives are presented. The filter was designed to keep the motor terminal from the cable surge impedance to reduce overvoltage reflections ringing and the dv/dt, di/dt, at the motor terminals. Specially the output filter is used to limit the rate of the inverter output voltage and reduce common mode noise to the motor, The performance of the output filter is evaluated through simulations and experiment on PWM inverter-fed AC motor drive. An experimental PWM drive system reduction of conducted EMI was implemented on an available TMS320C31 microprocessor control board Finally, experimental result shows inverter output filter reduces more common mode voltage than low pass filter also reduce overoltage and ringing at the motor terminal.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2335-2343
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• 2018

This paper proposes an optimal damping control algorithm of the DTI (Direct Two-level Inverter) to miniaturize and reduce the weight of auxiliary power supply for railway vehicles. The conventional auxiliary power supply for railway vehicles uses a DC-DC converter to maintain the inverter input power from the line voltage smoothly. The proposed topology does not use a DC-DC converter for reducing of manufacturing and maintenance costs. It also proposes a DTI topology removed damping resistors that generate ground signal noise in a certain period. At this time, a resonance phenomenon of DC-link voltage occurs due to variation of the inductive load, and a method of controlling the resonance phenomenon of DC-link voltage is required. In order to suppress the resonance phenomenon of the DC-link voltage, at a point before resonance occurs, this paper introduces an algorithm to suppress the resonance phenomenon of DC-link voltage by compensating the resonance component of the q axis voltage of the synchronous reference frame. The proposed algorithm verifies the effect through simulation and experiment.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.4
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• pp.9-17
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• 2019

Sun power generation systems which use large capacity centralized inverters have loss of power generation due to cloud and building shadows, pollution, cell deterioration, etc. To minimize loss of power generation, decentralized solar power systems using multiple micro-inverters are being proposed as an alternative. A distributed solar power system consisting of a system-connected system uses power line communication to collect data from the micro-inverters. Power line communication has the advantage of using power lines without separate lines for data transmission, but in distributed solar power generation systems that use a large number of micro-inverters, the bit error rate is less reliable due to the phenomenon caused by limited transmission power, high load interference and noise, variable signal attenuation, and impedance characteristics. So we proposed wireless intelligent controller for micro-inverter that is used to build distributed solar power systems. and we design and implement that. Further, the proposed wireless intelligent controller for micro-inverter was used to establish a small-volume solar power plant to check its function and operation.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.1
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• pp.9-14
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• 2008

Since they use the low switching frequency in multilevel inverter systems, they generate the high low frequency harmonic components. Generally, LC filter is used at the output terminal of inverter systems to solve this problem. But it causes a voltage drop at the output terminal by use of damping resistors, and causes the problem in which system efficiency decreases due to power loss of the damping resistor. In this paper, we proposed an output filter design method for NPC three-level inverter systems with low switching frequency. And we analyzed the efficiency of the proposed filter system, and the effectiveness of the proposed system is verified by simulation and experimental results.

• Journal of Aerospace System Engineering
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• v.15 no.1
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• pp.32-39
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• 2021

Electric propulsion aircraft are being actively researched in the aviation field in recent years to solve environmental and noise problems caused by existing gas turbine engine. In particular, research on a thrust motor as a core component of an electric power propulsion system and an inverter for driving it is actively being conducted. In this paper, a motor with high specific power is selected to determine characteristics of aircraft that are sensitive to weight and volume. Power loss of the inverter is then simulated. In the simulation, the selected motor and power device were modeled using PSIM, a power electronics analysis tool. Inverter power loss according to switching frequency was then analyzed.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.4
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• pp.313-320
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• 2003

This paper deals with the optimal design of a elevator inverter system based on the customized IPM. The proposed method reduces dv/dt and di/dt, which resulted in the minimized conducted EMI noise without an additional circuitry. It only optimizes the value of gate resistor in the IGBT embedded in the IPM. In order to optimize the customized IPM to a elevator system, we simulated and measured the spike voltage and the motor surge voltage including the temperature variation due to the switching losses at the IPM case and heat-sink. As a result, thanks to the optimized value of the gate resister in the IPM, the conducted EMI noise is reduced approx. 5∼10 [dB$\mu$V] in a particular frequency domain.