• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.9
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• pp.54-61
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• 2016

A 6-Gbps single-ended receiver with a linear equalizer and a self-reference generator is proposed for a high-speed interface with the double data rate. The proposed single-ended receiver uses a common gate amplifier to increase a voltage gain for an input signal with low voltage level. The continuous-time linear equalizer which reduces gain to the low frequencies and achieves high-frequency peaking gain is implemented in the common gate amplifier. Furthermore, a self-reference generator, which is controlled with the resolution 2.1 mV using digital averaging method, is implemented to maximize the voltage margin by removing the offset noise of the common gate amplifier. The proposed single-ended receiver is designed using a 65-nm CMOS process with 1.2-V supply and consumes the power of 15 mW at the data rate of 6 Gbps. The peaking gain in the frequency of 3 GHz of the designed equalizer is more than 5 dB compared to that in the low frequency.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.923-933
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• 2016

This paper proposes a new method for evaluating Effective Load Carrying Capability(ELCC) and capacity credit(C.C.) of power system including Wind Turbine Generator(WTG) combined with Battery Energy Storage System(BESS). WTG can only generate electricity power when the fuel(wind) is available. Because of fluctuation of wind speed, WTG generates intermittent power. In view point of reliability of power system, intermittent power of WTG is similar with probabilistic characteristics based on power on-off due to mechanical availability of conventional generator. Therefore, high penetration of WTG will occur difficulties in power operation. The high penetration of numerous and large capacity WTG can make risk to power system adequacy, quality and stability. Therefore, the penetration of WTG is limited in the world. In recent, it is expected that BESS installed at wind farms may smooth the wind power fluctuation. This study develops a new method to assess how much is penetration of WTG able to extended when Wind Turbine Generator(WTG) is combined with Battery Energy Storage System(BESS). In this paper, the assessment equation of capacity credit of WTG combined with BESS is formulated newly. The simulation program, is called GNRL_ESS, is developed in this study. This paper demonstrates a various case studies of ELCC and capacity credit(C.C.) of power system containing WTG combined with BESS using model system as similar as Jeju island power system. The case studies demonstrate that not only reasonable BESS capacity for a WTG but also permissible penetration percent of WTG combined with BESS and reasonable WTG capacity for a BESS can be decided.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.1
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• pp.51-56
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• 1999

This paper presents a new transient overvoltage blocking device (TOBD) for info-communication facilities with low power and high frequency bandwidth. Conventional protection devices have some problems such as low frequency bandwidth, low energy capacity and high remnant voltage. In order to improve these limitations, thehybrid type TOBD, which consists of a gas tube, avalanche diodes and junction typefield effect transistors (JFETs), was designed and fabricated. The TOBD differs from the conventional protection devices in configuration, and JFETs were used as an active non-linear element and a high speed switching diode with low capacitance limits high current. Therefore the avalanche dilde with low energy capacity are protected fromthe high current, and the TOBD has a very small input capacitance. From the performance test using combination surge generator, which can produce $1.2/50\mus\;4.2kV_{max}\; 8/20\mus\; 2.1kA_{max}$, it is confirmed that proposed TOBD has an excellent protection performance in tight clamping voltage and limiting current characteristics.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.475-478
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• 2005

Ducted rocket produces thrust by 2 steps, primary incomplete combustion in the gas generator, and secondary complete combustion reaction in combustion chamber mixed by air taken through duct. the range of a rocket is determined by the weight of propellant, especially the weight of fuel. So ducted rocket has more efficiency and high terminal speed compared to traditional solid rocket motor. This propulsion system expected to be applied to various kinds of missile for anti-aircraft, anti-ship

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.4
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• pp.199-204
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• 2003

This paper proposes reconfigurable hardware structures for spreading and scrambling of multi-mode CDMA systems. The proposed reconfigurable structures supporting IS-95, cdma2000 and WCDMA, include a pseudo noise code generator, a channelization code generator and a control circuit for signal flow control. The proposed reconfigurable structures provide an efficient hardware usage for multi-mode CDMA systems. The synthesis results show the area reduction about 24.7% compared with the original code generators. The proposed structures can provide efficient reconfigurability and high speed operations for future SDR systems.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.53-55
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• 2008

In high speed applications, the slotless permanent magnet(PM) motors appear an attractive solution, being almost insensitive to magneto-motive force harmonics and to pulse width modulation(PWM) current ripple and exhibiting lower stator iron losses and rotor losses (significant with square wave current control). So, this paper deals with methods for design of permanent magnet synchronous motor/generator.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.493-501
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• 2012

A rotational force generator for molten metal is developed using a linear motor design technology. Also, the developed device is applied to reproduce aluminum scraps and easy to control the rotate, stop, and forward and reverse rotation of molten metal. In addition, the developed device improves the melting speed and reproduction rate about 250 (%) and 96-99 (%), respectively, compared to the conventional handmade methods. Because it generates almost no dusts, it can improve working environments in a factory. Also, it has no losses in energy because it directly melts scraps. The device generates small amounts of the loss in refractory materials and aluminum caused by its oxidation because the molten metal is continuously rotated in which the loss and oxidized aluminum are the problems in the conventional melting and holding furnaces. Thus, it is possible to extend the life of furnaces and to produce high quality aluminum products.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.160.2-160.2
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• 2011

바다를 가로막는 방벽이나 방조제의 배수갑문 또는 조력발전소의 수문과 같이 인공 해양구조물을 통하여 흐르는 고속 해류를 이용하여 발전하는 해류발전 방식에 있어서, 고속 해류에 적합한 수차터빈과 발전기의 특성을 알아보았다. 조석간만의 차가 큰 지역에 설치되는 인공 해양구조물을 지나는 해류는 인공 해양구조물 전후에 발생하는 해수의 위치에너지 차이가 운동에너지로 바뀌면서 조석간만의 자연현상에 의해 발생되는 조류의 속도보다 훨씬 더 빠르게 흐른다. 이론적으로 우리나라의 서해안의 조석간만의 범위 3~8m로부터 7.5~12m/s 정도의 고속 해류가 가능하다. 이러한 경우에 적합한 해류발전기는 수차터빈 날개지름의 크기가 5m에서부터 12m 이하이면서, 증속기어박스와 발전기, 유압시스템 및 냉각시스템 그리고 전력변환장치를 포함하는 발전시설들을 해수면 위에 설치하는 것이 바람직하다.

• Journal of electromagnetic engineering and science
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• v.17 no.1
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• pp.39-43
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• 2017

In this paper, a systematic and statistical calibration technique was implemented to calibrate a high-speed signal converting system containing multiple digital-to-analog converters (DACs). The systematic error (especially the imbalance between DACs) in the current combining network of the multi-DAC system was modeled and corrected by calculating the path coefficients for individual DACs with wideband reference signals. Furthermore, by applying a Kalman filter to suppress noise from quantization and clock jitter, accurate coefficients with minimum noise were identified. For correcting an arbitrary waveform generator with two DACs, a co-simulation platform was implemented to estimate the system degradation and its corrected performance. Simulation results showed that after correction with 4.8 Gbps QAM signal, the signal-to-noise-ratio improved by approximately 4.5 dB and the error-vector-magnitude improved from 4.1% to 1.12% over 0.96 GHz bandwidth.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.23-24
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• 2007

Most of modern wind turbines employs a doubly-fed induction generator (DFIG) system because it has many advantages due to variable-speed operation, relatively high efficiency and it small converter size. The DFIG system uses a wound rotor induction machine so that the magnetizing current of the generator can be fed from both the stator and the rotor. This paper presents a protection relaying algorism for DFIG using the DQ equivalent circuits. The induced voltages calculated from the stator and rotor sides are nearly the same in the steady state. They become different in the DQ equivalent circuits during an internal fault. The proposed algorithm compares the inducted voltages estimated from the stator and the rotor circuit converted into the stationary reference frame. If the difference between the induced voltages exceeds the threshold, the proposed algorithm detects an turn-to-turn fault.