• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.5
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• pp.335-342
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• 2022

In this paper, a single-bit 3rd-order feedforward delta sigma modulator is proposed for audio applications. The proposed modulator is based on a class-C inverter for low voltage and power applications. For the high-precision requirement, the class-C inverter with regulated cascode structure increases its DC gain and acts as a low-voltage subthreshold amplifier. The proposed Class-C inverter-based modulator is designed and simulated in 180-nm CMOS process. With no performance loss and a low supply voltage compatibility, the proposed class-C inverter-based switched-capacitor modulator achieves high power efficiency. This design achieves an signal-to-noise-and-distortion ratio (SNDR) of 93.9 dB, an signal-to-noise ratio (SNR) of 108 dB, an spurious-free dynamic range (SFDR) of 102 dB, and a dynamic range (DR) of 102 dB at a signal bandwidth of 20 kHz and a sampling frequency of 4 MHz, while only using 280 μW of power consumption from a 0.8-V power supply.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1193-1195
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• 2002

This paper presents Active-clamp Class-E high frequency resonant inverter with single-stage. The proposed circuit is integrated Active-c class-E circuit to boost converter with the funct power factor correction. Boost converter is opera positive and negative half cycle respectively at frequency(60Hz), operating in Discontinuous Con Mode(DCM) of boost converter performs high p factor. By adding active-clamp circuit in Cl inverter, main switch of inverter part is operat only ZVS(Zero Voltage Switch), but also reduce switching voltage stress of main switch. Simulation result using Psim4.1 show that the p prove the validity of theoretical analysis. This proposed inverter will be able to be pract used as a power supply in various fields are ind heating applications, DC-DC converter etc.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.3
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• pp.101-105
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• 2004

The efficient power MOSFET inverter applied for a simple and low cost power supply is proposed for driving the dielectric barrier discharge (DBD) lamp load. For decades, the DBD phenomenon has been used for ozone gas production in industry. In this research, the ultraviolet and visible light sources utilizing the DBD lamp is considered as the load for solid-state high frequency power supply. It is found that the simple voltage-source single-ended quasi-resonant ZVS inverter with only one active power switch could effectively drive this load with the output power up to 700 W. The pulse density modulation based control scheme for the single-ended quasi-resonant ZVS inverter using a low voltage and high current power MOSFET switching device is proposed to provide a linear power regulation characteristic in the wide range 0-100％ of the full power as compared with the conventional control based Royer type parallel resonant inverter type power supplies.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1284-1286
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• 2001

In this paper, the operating characteristics of a 3 kW class grid-interactive photovoltaic(PV) power system was analysed from January 1998 to December 2000. The construction of the PV system includes a DC/AC inverter for grid connection, PV module, and data Monitoring & Acquisition system. The major results of the field test of the 3 kW class grid-interactive PV system showed that the system utilization rate was 13.83% the conversion efficiency of the inverter was 88% at an over half load, and the PV system generated the electricity more then 300 kWh per month.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.31-33
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• 1999

In this paper, a operating characteristics of the 50 kW grid-connected Photovoltaic(PV) Power system which is by means of initial PV datum analyzing is reported. The development of a 50 kW class photovoltaic power generation system including a DC/AC inverter is suggested to investigate the system performance for grid connection. The results of the demonstration test of a 50 kW class grid-connected PV system show that the system utilization rate is 15.6% and the inverter efficiency is 94% at 80% load.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.324-329
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• 2003

Asynchronus high speed turbo blower of 100HP class with gas bearing supports is developed. The high speed motor is cooled by air and it's RPM is controlled by high frequency inverter to adjust inlet flow rate. Product family is ranged from 50 to 200HP and covered by three frames. Highly efficient impeller is designed and proved by performance test on system. Overall measured system efficiency is 82% including motor and inverter. The motor efficiency is about 95%. It is designed to guarantee to operate at ambient temperature of 35 Deg.C and max 45 DegC. Gas bearing with high load capacity is developed to support heavy rotor on low rotational speed.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1788-1790
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• 2005

In this paper, an operating characteristics of a 50 kW gird-connected photovoltaic(PV) power system was analysed from 2000 to 2004. The construction of the PV system includes a 3-phase inverter for grid connection, PV module, distribution box, and data monitoring system. The major results of the demonstration test of the 50 kW class gird-connected PV system showed that efficiency of PV system was 11.13%, and the conversion efficiency of the inverter was 92% at a 50% load.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.117-122
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• 1992

In systems in which inductive coupling between a pancake-shaped coil on the surface of the body and a similar coil within the body is utilized for the transfort of electromagnetic energy, the minimization of temperature rise in the tissue is intimately related to the achievement of minimum losses in the region of the implanted coil. The new class of amplifiers, named "class E", for inverter is defined and is illustrated by a detailed description and a set of desist equations for one simple member of the class. For TET circuit the authors measured 65 to 76 percent efficiency at 1985kHz at 30 to 50 W output from IRF250 MOSFET transistor.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.519-520
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• 2006

In this paper, to evaluate the grid-connected 120kW class Photovoltaic(PV) system performance, as a consisted of solar cells, PCS, 150kVA transformer station. The paper address modeling and analysis of a grid-connected 120kW class photovoltaic generation system(PV system) PSCAD/EMTD and Psim. A PWM voltage source inverter(VIS) and its current control scheme have been implemented. A P&O(Perturbation and Observation) MPPT algorithms technique modeling has been simulated and analysed.

• Journal of IKEEE
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• v.19 no.1
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• pp.110-117
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• 2015

In this paper, a novel trench power MOSFET using a Separate-W-gated technique MOSFET (SWFET) is proposed. Because the SWFET has a very low $Q_{GD}$ compared to other forms of technology, it can be applied to high-speed power systems. The results found that the SWFET-applied $Q_{GD}$ was decreased by 40% when compared to simply using the more conventional trench gate MOSFET. $C_{ISS}$ (input capacitance : $C_{GS}+C_{GD}$), $C_{OSS}$ (output capacitance : $C_{GD}+C_{DS}$) and $C_{RSS}$ (reverse recovery capacitance : $C_{GD}$) were improved by 24%, 40%, and 50%, respectively. The switching characteristics of the inverter circuit shows a 24.9% enhancement of reverse recovery time, and the power efficiency of the DC-DC buck converter increased by 14.2%. In addition, the proposed SWFET does not require additional process steps and There was no degradation in the electrical performance of the current-voltage and on-resistance.