• 한국전자파학회논문지
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• 제16권5호
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• pp.455-464
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• 2005

본 논문에서는 손실이 있는 전송선로의 전달 임피던스를 적용한 열전형 전압 변환기(TVC)의 모델을 제안하였으며, TVC의 교류-직류 변환 차이를 계산하기 위한 프로그램을 개발하였다. 제안된 TVC는 열전소자(TE)와 열전소자의 측정범위를 확대하기 위한 저항선이 동축형 실린더의 중심에 직선형태로 직렬로 연결되었다. 제안된 TVC의 교류-직류 변환 차이를 실린더의 직경, 열전도도 등의 특성을 적용하여 시뮬레이션 하였다. 시뮬레이션 값이 불확도 이내에서 측정값과 잘 일치하였다. 일치도는 주파수 $40Hz\~10kHz$에서는 $1{\mu}V/V$이하였고, $20kHz\~100kHz$에서는 $5{\mu}V/V$이하였으며, $200kHz\~1MHz$에서는 최대 $12{\mu}V/V$이하의 차이를 보였다.

• Journal of Power Electronics
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• 제3권4호
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• pp.230-238
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• 2003

Electric vehicles (EV) demands for greater acceleration, performance and vehicle range in pure electric vehicles plus mandated requirements to further reduce emissions in hybrid electric vehicles (HEV) increase the appeal for combined on-board energy storage systems and generators. And the power electronics plays an important role in providing an interface between fuel cells (FC) and loads. This paper deals with a multiple input DC-DC power converter devoted to combine the power flowing of multi-source on energy systems. The multi-source is composed of (i) FC system as a prime power demands, (ii) super capacitor banks as energy storage devices for high and intense power demands, (iii) superconducting magnetic energy storage system (SMES), (iv) multiple input DC-DC power converter and (v) a three phase inverter-fed permanent magnet synchronous motor as a drive. In this system, It is used super capacitor banks and superconducting magnetic energy replaces from the battery system. The modeling and transient performance simulation is effective for reducing transient influence caused by sudden charge of effective load. The main purpose of power electronic converters is to convert the DC power output from the fuel cell and other to a suitable AC voltage, which can be connected to electric loads directly (PMSM). The fuel cell and other output is connected to the DC-DC converter, which regulates the DC link voltage.

• 조명전기설비학회논문지
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• 제14권4호
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• pp.8-15
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• 2000

본 논문에서는 F 컨버터의 능동형 PFC 시스템을 구성하고, 진력 변환시 입력 전류를 전원 전압과 동장연 정현파로 제이하는 동시에 출력 전압에 포함되는 고조파 등의 잡음을 제거하고 직류 출력 전압을 제어하기 위한 PWM-PFM 제어 기법을 제시하였다. 부하단에서 필요한 전압과 높은 전력 효율을 얻기 위하여 인버터 단계애서 전류 성형 제어를 실행한 후, 순방­향(forward) 컨버터에 의해 다시 직류 전압으로 변환시켜 부하단으로 출력한다. 입력 전압이 30[V]이교 승압 (boost) 인덕터가 1.1[mH]일 때 정격 출력은 전압 50[V], 전류1[A], 듀티비 0.5 이상으로 하여 부하 처항에 따른 전압 변화를 PWM-PFM 제어 기법을 이용하며 제어하였고, 전류 성형 기법을 이용하여 0.93획 역률로 고조파를 감쇠 및 개선하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.436-439
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• 2011

본 논문은 클록 보정회로를 가진 1V 2.56-GS/s 6-bit flash analog-to-digital converter (ADC) 제안한다. 제안하는 ADC 구조에서 아날로그 블록은 단일 T/H와 2단의 프리앰프, 그리고 비교기를 사용된다. 2단의 프리앰프와 비교기의 출력에 옵셋의 크기를 줄이기 위하여 저항 평균화 기법을 적용하였다. 디지털 블록은 quasi-gray rom base 구조를 사용한다. 3입력 voting 회로로 flash ADC에서 발생하기 쉬운 bubble error를 제거하였으며, 고속 동작을 위해 단일 클록을 사용하는 TSPC F/F로 구현한다. 제안하는 flash ADC는 클록 듀티 비를 조절할 수 있는 클록 보정회로를 사용한다. 클록 보정 회로는 비교기 클록 듀티 비를 조절하여 리셋 시간과 evaluation 시간의 비율을 최적화함으로 dynamic 특성을 확보한다. 제안한 flash ADC는 1V 90nm의 CMOS 공정에서 설계되었다. Full power bandwidth인 1.2 GHz 입력에 대하여 ADC 성능을 시뮬레이션을 통해 확인하였다. 설계된 flash ADC의 면적과 전력소모는 각각 $800{\times}400\;{\mu}m^2$와 193.02mW 이다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권1호
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• pp.83-91
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• 2014

This paper presents a capacitive readout circuit for tri-axes microaccelerometer with sub-fF offset calibration capability. A charge sensitive amplifier (CSA) with correlated double sampling (CDS) and digital to equivalent capacitance converter (DECC) is proposed. The DECC is implemented using 10-bit DAC, charge transfer switches, and a charge-storing capacitor. The DECC circuit can realize the equivalent capacitance of sub-fF range with a smaller area and higher accuracy than previous offset cancelling circuit using series-connected capacitor arrays. The readout circuit and MEMS sensing element are integrated in a single package. The supply voltage and the current consumption of analog blocks are 3.3 V and $230{\mu}A$, respectively. The sensitivities of tri-axes are measured to be 3.87 mg/LSB, 3.87 mg/LSB and 3.90 mg/LSB, respectively. The offset calibration which is controlled by 10-bit DECC has a resolution of 12.4 LSB per step with high linearity. The noise levels of tri-axes are $349{\mu}g$/${\sqrt}$Hz, $341{\mu}g$/${\sqrt}$Hz and $411{\mu}g$/${\sqrt}$Hz, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.213-215
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• 2001

We investigated the frequency characteristics of surges induced on Lan equipments by using V-F converter. which installed on the second part of protection system. We stored and analyzed the frequency converting data with the amplitude of overvoltage. In addition. The data acquisition system was made so that we could be examine the results wave through WEB. From this results, it is found that this frequency analysis could be helped for design and protection of various undesired surges.

• 대한전기학회논문지
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• 제32권3호
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• pp.90-98
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• 1983

The method to improve the efficiency of a slightly loaded induction motor is suggested. It is based upon the optimal efficiency slip tracking by adjusting the voltage to frequency ratio(V/f). It is adopted the converter-inverter fed induction motor drive system. All the control loops are implemented bh the Z-80 microprocessor. By this method, 10% or more improvement is achieved at a few fraction of the full load.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.312-316
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• 1987

A simple hybrid circuit to control the two-phase AC motor of the nut-runners which employ the tightening torque control system is described in this paper. The circuit has emphasis on the low-cost implementation. The circuit constitutes of the V/F converter using a timer IC, the pulse width modulator using the fastening torque signal and the two-phase logic sequencer.

• Transactions on Electrical and Electronic Materials
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• 제12권6호
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• pp.262-266
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• 2011

A simulation study of a current-mode direct current (DC)-DC boost converter is presented in this paper. This converter, with a fully-integrated power module, is implemented by using bipolar complementary metal-oxide semiconductor (BiCMOS) technology. The current-sensing circuit has an op-amp to achieve high accuracy. With the sense metal-oxide semiconductor field-effect transistor (MOSFET) in the current sensor, the sensed inductor current with the internal ramp signal can be used for feedback control. In addition, BiCMOS technology is applied to the converter, for accurate current sensing and low power consumption. The DC-DC converter is designed with a standard 0.35 ${\mu}m$ BiCMOS process. The off-chip inductor-capacitor (LC) filter is operated with an inductance of 1 mH and a capacitance of 12.5 nF. Simulation results show the high performance of the current-sensing circuit and the validity of the BiCMOS converter. The output voltage is found to be 4.1 V with a ripple ratio of 1.5% at the duty ratio of 0.3. The sensing current is measured to be within 1 mA and follows to fit the order of the aspect ratio, between sensing and power FET.

• 전기학회논문지P
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• 제60권4호
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• pp.253-256
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• 2011

LEDs have small size, long lifespan, high reliability, low power consumption and high color efficiency. Using such a characteristics, LED Back Light Unit has been studying actively. This paper proposes LED driver to minimize power consumption due to LED forward voltage($V_F$) difference and temperature rising. Compared to conventional LED driver, the proposed driver have excellent stability, brief structure and linear output voltage of DC-DC boost converter. Proposed LED Driver circuit was designed using 0.35um CMOS technology. And its operation was verified through simulation.