• 제목/요약/키워드: voltage standard

검색결과 977건 처리시간 0.032초

362 kV GIB 내에서 건조공기의 절연파괴 특성 (Breakdown Characteristics of Dry Air under 362 kV GIB)

  • 한기선;주형준;윤진열;유홍근
    • 한국전기전자재료학회논문지
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    • 제23권10호
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    • pp.804-808
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    • 2010
  • In this paper, we studied the dielectric breakdown voltage characteristics by the AC withstand voltage test on using green insulation dry air instead of $SF_6$ insulation gas used in the GIB (gas insulated bus) of 362 kV GIS (gas insulated switchgear). The AC withstand voltage test applied to the standard KEPCO's 362 kV GIB with dry air insulation, and the equivalence of dielectric breakdown voltage for dry air and $SF_6$ gas were examined, and the empirical formulas of dielectric breakdown voltage for dry air were calculated, and the criterion of AC withstand voltage test for dry air insulation was derived. Using the criterion, dry air can be used instead of $SF_6$ gas for 362 kV GIB in the factory acceptance test was confirmed.

전원 잡음 영향을 줄이기 위한 VCO 정전압기 분석 (An Analysis of n VCO Voltage Regulator for Reducing the Effect of Power Supply Noise)

  • 허호영;정항근
    • 한국산학기술학회논문지
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    • 제10권2호
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    • pp.269-273
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    • 2009
  • 정전압기는 VCO의 제어전압의 전원 잡음을 줄이기 위해 사용될 수 있다. 정 전압기의 최적 설계를 위해선 정전압기에 대한 정확한 해석이 필요하다. 본 논문에서는 최근 발표된 논문의 정전압기 해석 과정에 MOSFET의 기생 커패시턴스 성분을 고려하지 않은 문제점을 보완하였다. 이 문제점을 이론적으로 분석하여 정확한 해석을 유도하였고, 회로 시뮬레이션과 측정을 통해 검증하였다. 정전압기는 $0.18{\mu}m$ 1P6M CMOS 공정으로 설계되었고, 칩 면적은 $1mm^2$ 이다.

CCVT 2차 전압 보상 방법 (Compensation Algorithm of CCVT's Secondary Voltages)

  • 강용철;이병은;김은숙;정태영;이지훈;소순홍;차선희;김연희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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    • pp.93-95
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    • 2005
  • Coupling capacitor voltage transformers (CCVT) are widely used in high voltage power systems to obtain standard low voltage signal for protective relaying and measuring instruments. To obtain high accuracy, capacitances and inductances are tuned to the power system frequency, making a parallel resonant circuit. When no fault occurs, no distortion of the secondary voltage is generated. However, when a fault occurs, harmonics generated break the resonance between capacitances and inductance, which generates the distortion of the secondary voltage. This paper proposes an algorithm for compensating the secondary voltage of the CCVT. With the values of the secondary voltage of the CCVT, the secondary currents, the primary currents and the voltages across the capacitors and inductor are calculated. Test results indicate that the proposed algorithm can compensate the distorted secondary voltage of the CCVT, and is irrespective of the fault distance, the fault inception angle and the burden.

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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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    • 제12권1호
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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.

하이브리드 자동차용 고압 케이블의 온도 특성에 관한 연구 (A Study on the Temperature Characteristics of High Voltage Power Cable for Hybrid Electric Vehicle)

  • 이기연;김동우;김동욱;길형준;김향곤;최충석
    • 전기학회논문지P
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    • 제57권3호
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    • pp.338-342
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    • 2008
  • Hybrid Electric Vehicle(HEV) is driven by an internal-combustion engine and an electric motor. It is a combination of an internal-combustion engine and several electrical equipments which use a high voltage battery, an electric motors, an inverter and others. But there is not any separate detailed enforcement regulations for high voltage electric appliances in the existing vehicle-related safety standards. So, test standards suggestion as well as test technique development need to be done for ensuring electrical safety, for an electric motor, a high voltage battery, a(n) inverter/converter and an electric power transmission units and other equipments to ensure the safety of high voltage electric appliances which is the HEV key electrical component. In this paper, We are to provide helpful data to support test technique development and test standard establishment for HEV design and electrical safety security by the following methods; by measuring the voltage, the electric current, and the frequency of HEV, by analyzing electrical characteristics of high voltage electric appliances, and by analyzing temperature characteristics of the electrical current among the analyzed electrical characteristics by thermal imagining cameras.

22.9kV 수전설비에서 측정된 과도과전압의 특성 (Features of Transient Overvoltages Observed at 22.9kV Consumer's Substation)

  • 심해섭;이복희
    • 조명전기설비학회논문지
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    • 제28권9호
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    • pp.52-59
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    • 2014
  • The aims of this paper are to characterize the transient overvoltages(TOVs) and to evaluate the risk occurring at 22.9kV consumer's substation. The measurements of lightning- and switching-caused TOVs were made during Mar. 2013 and Feb. 2014. As a consequence, 47 events of TOVs were recorded and 4 of them were higher than the input voltage envelope(IVE) of the information technology industry council(ITI) curve. The measured TOVs are characterized by longer front times and longer durations compared to the $1.2/50{\mu}s$ standard impulse voltage waveform, and some of them represent bipolar waves with lower oscillation frequencies. It suggests that the test of non-standard impulse voltage waveforms is needed for effective risk assessments of power apparatus. Lightning- and switching-caused TOVs exceeding IVE of ITI curve are induced at the secondary of 22.9kV potential transformer(PT). We may, therefore, conclude that the surge protection devices should be applied at the secondary of PT and the surge absorbers should be installed at the primary of VCB or PT. The results presented in this paper could be useful to design the reasonable insulation coordination for 22.9kV consumer's substation.

전기용량 부담을 이용한 전압변성기 비교 측정 시스템의 비오차 및 위상각 오차의 직선성 평가기술 (Evaluation Technique of Linearity of Ratio Error and Phase Angle Error of Voltage Transformer Comparison Measurement System Using Capacitor Burden)

  • 정재갑;김한준;권성원;김명수
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제54권6호
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    • pp.274-278
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    • 2005
  • Voltage transformer(VT) comparison measurement system is usually used for measurements of ratio error and phase angle error of VT made in industry. Both ratio error and phase angle error in VT are critically influenced by values of burden of VT used. External burden effects on both ratio error and phase angle error in VT are theoretically calculated. From the theoretical calculation, a method of evaluation for linearity of ratio error and phase angle error in VT measurement system have been developed using the standard capacitive burdens, with negligible dissipation factor less than 10$^{-4}$. These burden consists of five standard capacitors, with nominal capacitance of 1.1 $\mu$F, 1 $\mu$F, 0.1 $\mu$F, 0.01 $\mu$F, 0.001 $\mu$F. The developed method has been applied in VT measurement system of industry, showing in good consistency and linearity within 0.001 $\%$ between theoretical and measured values.

High voltage MOSFET fabricated by using a standard CMOS logic process to drive the top emission OLEDs in silicon-based OELDs

  • Lee, Cheon-An;Kwon, Hyuck-In;Jin, Sung-Hun;Lee, Chang-Ju;Lee, Myung-Won;Kyung, Jae-Woo;Cho, Il-Whan;Lee, Jong-Duk;Park, Byung-Gook
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.981-983
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    • 2003
  • Using the conventional standard CMOS logic process, the high voltage MOSFET to drive top emission OLEDs was fabricated for the silicon-based organic electroluminescent display. The drift region of the conventional high voltage MOSFET was implemented by the n-well of the logic process. The measurement result shows a good saturation characteristic up to 50 V without breakdown phenomena.

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전극 형태에 따른 가교폴리에틸렌 절연체의 방전분포해석 (The Discharge Distribution Analysis of Cross-Linking Polyethylene due to Shape of Electrode)

  • 김탁용;양재훈;김귀열;이충호;홍진웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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    • pp.308-311
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    • 2004
  • In this paper, we investigated $\phi-q-n$ distribution to inquire discharge characteristic according to variation of electrode. Also, we investigated Weible distribution of discharge number using Weible analysis to search the relationship between a part discharge and shape of electrode. We increased voltage 1[kV] AC 60[Hz] of impressed voltage, data is acquired a generating discharge for 10 seconds after impressing voltage. Also, as we repeated the experiment 10 times at same condition, analyzed foible using data except for maximum and minimum. As the result, we confirmed that discharge generating and discharge quantity were significantly increased narrowing radius of electrode, also discharge frequency was close to shape of a standard distribution.

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Training an Artificial Neural Network (ANN) to Control the Tap Changer of Parallel Transformers for a Closed Primary Bus

  • Sedaghati, Alireza
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2004년도 ICCAS
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    • pp.1042-1047
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    • 2004
  • Voltage control is an essential part of the electric energy transmission and distribution system to maintain proper voltage limit at the consumer's terminal. Besides the generating units that provide the basic voltage control, there are many additional voltage-controlling agents e.g., shunt capacitors, shunt reactors, static VAr compensators, regulating transformers mentioned in [1], [2]. The most popular one, among all those agents for controlling voltage levels at the distribution and transmission system, is the on-load tap changer transformer. It serves two functions-energy transformation in different voltage levels and the voltage control. Artificial Neural Network (ANN) has been realized as a convenient tool that can be used in controlling the on load tap changer in the distribution transformers. Usage of the ANN in this area needs suitable training and testing data for performance analysis before the practical application. This paper briefly describes a procedure of processing the data to train an Artificial Neural Network (ANN) to control the tap changer operating decision of parallel transformers for a closed primary bus. The data set are used to train a two layer ANN using three different neural net learning algorithms, namely, Standard Backpropagation [3], Bayesian Regularization [4] and Scaled Conjugate Gradient [5]. The experimental results are presented including performance analysis.

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