• Title/Summary/Keyword: current-voltage

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Breakdown Voltage Improvement in SOI MOSFET Using Gate-Recessed Structure (게이트가 파인 구조를 이용한 SOI MOSFET에서의 항복전압 개선)

  • 최진혁;박영준;민홍식
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.12
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    • pp.159-165
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    • 1995
  • A gate-recessed structure is introduced to SOI MOSFET's in order to increase the source-to-drain breakdown voltage. A significant increase in the breakdown voltage is observed compared with that of a planar single source/drain SOI MOSFET without inducing the appreciable reduction of the current drivability. We have analyzed the origin of the breakdown voltage improvement by the substrate current measurements and 2-D device simulations, and shown that the breakdown voltage improvement is caused by the reductions in the impact ionization rate and the parasitic bipolar current gain.

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Analysis on Voltage Rise of Rail in High speed Railway System (고속철도 시스템의 레일 전위 상승 해석)

  • 이종우
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.8
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    • pp.481-485
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    • 2003
  • In electric railway system, potential of rail has been risen, for return-current flows through rail. The magnitude of rising voltage is different to railway feed system, ground admittance of rail and the load current. If rising voltage of rail is large, electric shock can be occurred to passengers and maintenance- worker, In this paper, we estimate the rising voltage of rail in high speed railway system and check the safety to human beings.

Sinusoidal Tracking Control of Voltage Source PWM Converter by Input Current Estimation (입력전류추정에 의한 전압형 PWM 컨버터의 정현추종제어)

  • 허태원;박지호;신동률;김춘삼;우정인
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.4
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    • pp.39-47
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    • 2000
  • This paper presents the sinusoidal tracking controller in error to eliminate the steady state control error and to improve the transient characteristics for input current in voltage source PWM converter with input current estimation. The estimation method of input current values and configuration of controller are described. DC output voltage is controlled by PI controller, and sinusoidal tracking current controller which tracks directly AC input current is used as input current controller. The sinusoidal tracking current controller can be used without any coordinate transformation algorithms.It is proved that the steady state deviation of input current reduces to zero and the proposed control system is not affected by input voltage from transfer functions of input current control system. The validity of proposed scheme is verified by simulations and experimental results for load resister and input voltage variation.

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A Highly Accurate BiCMOS Cascode Current Mirror for Wide Output Voltage Range (광범위 출력전압을 위한 고정밀 BiCMOS cascode 전류미러)

  • Yang, Byung-Do
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.3
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    • pp.54-59
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    • 2008
  • A highly accurate wide swing BiCMOS cascode current mirror is proposed. It uses the base-current compensated BJT current mirror. It increases both output impedance and output voltage range by using the npn-NMOS cascode instead of the NMOS-NMOS cascode. The npn transistor copies the input current and the NMOS transistor increases the output impedance for the accurate current mirroring. The proposed current mirror achieves highly constant current for wide output voltage range. Simulation results were verified with measurements performed on a fabricated chip using a 5/16V 0.5um BCD process. It has only $-2.5%{\sim}1.0%$ current error for $0.3V{\sim}16V$ output voltage range.

Current Source Type Pulse Generator with Improved Output Voltage Waveform for High Voltage Capacitively Coupled Plasma System (고전압 용량성 결합 플라즈마 시스템의 개선된 전압 파형 출력을 위한 펄스 전류 발생장치 회로)

  • Chae, Beomseok;Min, Juhwa;Suh, Yongsug;Kim, Hyunbae
    • The Transactions of the Korean Institute of Power Electronics
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    • v.24 no.3
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    • pp.153-160
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    • 2019
  • This study proposes a current source-type pulse generator to improve output voltage and current waveforms under a capacitively coupled plasma (CCP) system. The proposed circuit comprises two parallel-connected current source-type converters. These converters can satisfy the required output waveforms of plasma processing. The parallel-connected converters operate without reverse current fault by applying a time-delay control technique. Conventional voltage source converters based on pulse power supply exhibit drawbacks in short-circuit current, and problems occur when they are applied to a CCP system. The proposed pulse power supply based on a current source converter fundamentally solves the short-circuit current problem. Therefore, this topology can improve the voltage and current accuracy of a CCP system.

Method for improving the accuracy of a voltage transformer considering hysteresis characteristics (히스테리시스 특성을 고려한 전압 변성기 오차 개선 방법)

  • Kang, Yong-Cheol;Lee, Byung-Eun;Park, Jong-Min;Cha, Sun-Hee;Jang, Sung-Il;Kim, Yong-Guen
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.208-209
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    • 2006
  • Voltage Transformer is used to transform high voltage into low voltage to input signal of protection relay. Most of the Voltage Transformers use the iron core which maximizes the flux linkage. The ratio of the Voltage Transformer depends on the transformer turns ratio. The current which flows in the Voltage Transformer has non-linear characteristic caused by hysteresis of the iron core, it causes a voltage loss in the winding impedances which makes measurement errors. This paper describes an error compensation method considering hysteresis characteristic. The proposed compensation method improves error by calculating the primary current from the exciting current of the hysteresis loop in the Voltage Transformer, compensating the voltage loss.

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A Study on Condenser Characteristics at the Series Connection of Condenser and Reactor Under Voltage Unbalance (전압 불평형에서 콘덴서와 리액터의 직렬 연결시의 콘덴서의 특성 분석)

  • Kim, Il-Jung;Kim, Jong-Gyeum;Park, Young-Jeen;Kim, Sung-Hun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.3
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    • pp.325-329
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    • 2010
  • Capacitor has been used principally for the power factor compensation long ago. However now it does as passive filter to reduce harmonics of nonlinear load with reactor. Most of the customer's low-voltage feeder has been designed with approximately balanced and connected at the 3 phase four wire system. But voltage and current unbalance is appeared by the mixing operation of single or three phase load etc. The addition of reactor at the condenser may rise its terminal voltage. Voltage and current values above rating can act on electrical stress on the condenser. In this paper, we calculated and measured that voltage, current and capacity of condenser are changed under the voltage balance. We conclude that magnitude and deviation of phase voltage act on major point of electrical stress.

Field Test of Optical Voltage and Current Meter (광 응용 전류 전압계의 현장실험)

  • Kim, K.C.;Song, J.T.;Song, W.S.;Kim, C.S.;Lee, K.C.;Lee, S.I.
    • Proceedings of the KIEE Conference
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    • 1992.07b
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    • pp.794-798
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    • 1992
  • We present an optical Voltage and current sensor using $BSO(Bi_{12}SiO_{20})$ monocrystal. The voltage and current sensor consist of PBS(Polarizing Beam Splitter), 1/4 wavelength plate, ZnSe, Selfoc lens, LED, and PIN-PD etc. Magnetic core was made using permalloy for applying magnetic field to current sensor effectively. Current was measured from 100 to 1,600 ampere and accuracy was about ${\pm}$5%. The accuracy could be improved to ${\pm}$l% after reducing the nonlinear property of BSO crystal using our own program in PC (IBM286). We noticed that these data were not influenced by 154,000 voltage at all. Applied voltage was reduced to 1/20 using capacitors. And experiment was carried out up to 450V of the reduced voltage. The data fran optical voltage sensor was similar to that from conventional voltage sensor. The accuracy of the data was within about ${\pm}$1%.

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The Impact of Gate Leakage Current on PLL in 65 nm Technology: Analysis and Optimization

  • Li, Jing;Ning, Ning;Du, Ling;Yu, Qi;Liu, Yang
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.1
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    • pp.99-106
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    • 2012
  • For CMOS technology of 65 nm and beyond, the gate leakage current can not be negligible anymore. In this paper, the impact of the gate leakage current in ring voltage-controlled oscillator (VCO) on phase-locked loop (PLL) is analyzed and modeled. A voltage -to-voltage (V-to-V) circuit is proposed to reduce the voltage ripple on $V_{ctrl}$ induced by the gate leakage current. The side effects induced by the V-to-V circuit are described and optimized either. The PLL design is based on a standard 65 nm CMOS technology with a 1.8 V power supply. Simulation results show that 97 % ripple voltage is smoothed at 216 MHz output frequency. The RMS and peak-to-peak jitter are 3 ps and 14.8 ps, respectively.

A Single-Input Single-Output Approach by using Minor-Loop Voltage Feedback Compensation with Modified SPWM Technique for Three-Phase AC-DC Buck Converter

  • Alias, Azrita;Rahim, Nasrudin Abd.;Hussain, Mohamed Azlan
    • Journal of Power Electronics
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    • v.13 no.5
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    • pp.829-840
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    • 2013
  • The modified sinusoidal pulse-width modulation (SPWM) is one of the PWM techniques used in three-phase AC-DC buck converters. The modified SPWM works without the current sensor (the converter is current sensorless), improves production of sinusoidal AC current, enables obtainment of near-unity power factor, and controls output voltage through modulation gain (ranging from 0 to 1). The main problem of the modified SPWM is the huge starting current and voltage (during transient) that results from a large step change from the reference voltage. When the load changes, the output voltage significantly drops (through switching losses and non-ideal converter elements). The single-input single-output (SISO) approach with minor-loop voltage feedback controller presented here overcomes this problem. This approach is created on a theoretical linear model and verified by discrete-model simulation on MATLAB/Simulink. The capability and effectiveness of the SISO approach in compensating start-up current/voltage and in achieving zero steady-state error were tested for transient cases with step-changed load and step-changed reference voltage for linear and non-linear loads. Tests were done to analyze the transient performance against various controller gains. An experiment prototype was also developed for verification.