• Title/Summary/Keyword: transient information

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Strip Rupture Detection System of Cold Rolling Mill using Transient Current Signal (과도 전류신호를 이용한 냉간 압연기의 판 터짐 검지 시스템)

  • Yang, S.W.;Oh, J.S.;Shim, M.C.;Kim, S.J.;Yang, B.S.;Lee, W.H.
    • Journal of Power System Engineering
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    • v.14 no.2
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    • pp.40-47
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    • 2010
  • This paper proposes a fault detection system to detect the strip rupture in six-high stand Cold Rolling Mills based on transient current signal of an electrical motor. For this work, signal smoothing technique is used to highlight precise feature between normal and fault condition. Subtracting the smoothed signal from the original signal gives the residuals that contains the information related to the normal or faulty condition. Using residual signal, discrete wavelet transform is performed and acquire the signal presenting fault feature well. Also, feature extraction and classification are executed by using PCA, KPCA and SVM. The actual data is acquired from POSCO for validating the proposed method.

The Stablity and Transient Response in the Buck-Boost DC-DC Converter (승강엽형 DC-DC 콘버어터의 안정도 및 과도 응답)

  • 김희준;김순창
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.28B no.5
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    • pp.421-430
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    • 1991
  • This paper investigated the errect of the right-half-plane zero on stability in the buck-boost DC-DC converter which is one type of the switching regulator and the stability region for the variation of the output current is obtained by evaluating the feedback gain. And it is clarified that the damping ratio decreases gradually by increase of the feedback loop gain and the regulation system of the converter becomes unstable, and from the transient response analysis we obtainedthe stability region about this converter. From above result it is known that the stability decreases by the existence of the right-half-plane zero. For the improvement of stability, we carried out one pole compensation in feedback circuit and obtained the avaliable stability region in relation to the gain bandwidth product from the stability and transient response analysis. These results were established experiment.

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Analysis of Transient Overvoltages within a 345kV Korean Thermal Plant

  • Yeo, Sang-Min;Kim, Chul-Hwan
    • Journal of Electrical Engineering and Technology
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    • v.7 no.3
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    • pp.297-303
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    • 2012
  • This paper presents the simulation results for the analysis of a lightning surge, switching transients and very fast transients within a thermal plant. The modeling of gas insulated substations (GIS) makes use of electrical equivalent circuits that are composed of lumped elements and distributed parameter lines. The system model also includes some generators, transformers, and low voltage circuits such as 24V DC rectifiers and control circuits. This paper shows the simulation results, via EMTP (Electro-Magnetic Transients Program), for three overvoltage types, such as transient overvoltages, switching transients, very fast transients and a lightning surge.

The Pulsed Id-Vg methodology and Its Application to the Electron Trapping Characterization of High-κ gate Dielectrics

  • Young, Chadwin D.;Heh, Dawei;Choi, Ri-No;Lee, Byoung-Hun;Bersuker, Gennadi
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.10 no.2
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    • pp.79-99
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    • 2010
  • Pulsed current-voltage (I-V) methods are introduced to evaluate the impact of fast transient charge trapping on the performance of high-k dielectric transistors. Several pulsed I-V measurement configurations and measurement requirements are critically reviewed. Properly configured pulsed I-V measurements are shown to be capable of extracting such device characteristics as trap-free mobility, trap-induced threshold voltage shift (${\Delta}V_t$), as well as effective fast transient trap density. The results demonstrate that the pulsed I-V measurements are an essential technique for evaluating high-$\kappa$ gate dielectric devices.

Study on the Thermal Transient Response of TSV Considering the Effect of Electronic-Thermal Coupling

  • Li, Chunquan;Zou, Meng-Qiang;Shang, Yuling;Zhang, Ming
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.3
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    • pp.356-364
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    • 2015
  • The transmission performance of TSV considering the effect of electronic-thermal coupling is an new challenge in three dimension integrated circuit. This paper presents the thermal equivalent circuit (TEC) model of the TSV, and discussed the thermal equivalent parameters for TSV. Si layer is equivalent to transmission line according to its thermal characteristic. Thermal transient response (TTR) of TSV considering electronic-thermal coupling effects are proposed, iteration flow electronic-thermal coupling for TSV is analyzed. Furthermore, the influences of TTR are investigated with the non-coupling and considering coupling for TSV. Finally, the relationship among temperature, thickness of $SiO_2$, radius of via and frequency of excitation source are addressed, which are verified by the simulation.

Transient Current Control of Two-Stage Electronics Ballast for HID Lamps (HID 램프용 Two-Stage 전자식 안정기의 과도 전류 제어)

  • Lee, Woo-Cheol
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.1
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    • pp.1-8
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    • 2014
  • The conventional Three-Stage electronic ballast is stable, but Two-Stage electronic ballast has been researching because of efficiency. Three-Stage electronic ballast is consisted of PFC circuit, buck converter, and inverter circuit, but Two-stage is consisted of PFC circuit, Buck-Inverter full bridge circuit. The Buck-Inverter full bridge inverter consists of two half bridge inverters for low frequency switching, and high frequency switching. In the case of street lamp it is far from a lamp to a ballast, the conventional pulsed high voltage ignitor can not turn on the HID lamps because of reduction of ignition voltage. Therefore, it needs to do the research on a resonant ignition to turn on the HID lamps. Therefore, in the Two-Stage electronic ballast which has the resonant tank for ignition, the transient resonant current because of low frequency changing is analyzed, the novel algorithm is proposed to resuce the transient current.

Dynamic Transient Phenomena of a Proton Exchange Membrane Fuel Cell

  • Lee, Ying;Choi, Yong-Sung;Zhang, You-Sai;Lee, Kyung-Sup
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.7
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    • pp.530-533
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    • 2010
  • The proton exchange membrane fuel cell (PEMFC) holds great promise of clean power. However, in practical applications which use the PEMFC as the power source, the output voltage from the fuel cell undergoes a transient response especially during acceleration and deceleration. This paper presents the relationships between the charge curves of the internal voltage rise, discharge curves of the internal voltage drop, the voltage with a time constant $V_{\tau}$ and finally, the load and time constant $\tau$ of $FC_1$ and $FC_2$, connected both in series and in parallel.

Transient Response Analysis of the Trigonometric Distributed RC Circuit (삼각함수형 RC분포회로의 과도응답해석)

  • 김덕진
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.4 no.4
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    • pp.13-18
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    • 1967
  • Since all the poles of the open circuit voltage transfer function of the trigonometric, linear, passive RC circuits exist on the negative real axis of s-plane, its transient response to the unit step input is monotonic. This satisfies the necessary conditions for the applicability of Elmore's method which had been developed originally for the transient analysis of lumped circuit in computing the rise time and delay time of the trigonometric distributed RC circuits. This paper describes the computing method of rise and delay times of the trigonometric distributed RC circuit. The analysis shows that the transient response of this kind circuit depends only upon the time constant and distance angle $\theta$. As $\theta$ is increased, the rise and delay titles are increased non-linearly.

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Effect of Interface Charges on the Transient Characteristics of 4H-SiC DMOSFETs (4H-SiC DMOSFETs의 계면 전하 밀도에 따른 스위칭 특성 분석)

  • Kang, Min-Seok;Moon, Kyoung-Sook;Koo, Sang-Mo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.6
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    • pp.436-439
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    • 2010
  • SiC power device possesses attractive features, such as high breakdown voltage, high-speed switching capability, and high temperature operation. In general, device design has a significant effect on the switching characteristics. In this work, we report the effect of the interface states ($Q_f$) on the transient characteristics of SiC DMOSFETs. The key design parameters for SiC DMOSFETs have been optimized by using a physics-based two-dimensional (2-D) mixed device and circuit simulator by Silvaco Inc. When the $SiO_2$/SiC interface charge decreases, power losses and switching time also decrease, primarily due to the lowered channel mobilities. High density interface states can result in increased carrier trapping, or more recombination centers or scattering sites. Therefore, the quality of $SiO_2$/SiC interfaces has a important effect on both the static and transient properties of SiC MOSFET devices.

Notes on Incompressible Theory of Hydrodynamic Pressureon Dams during Earthquakes (지진에 의하여 댐에 작용하는 동수압의 고전 이론에 대한 재고)

  • Jeong, Yong-Gwon
    • Journal of Korea Water Resources Association
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    • v.30 no.3
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    • pp.195-199
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    • 1997
  • Classical theory of hydrodynamic pressure on dams during earthquakes is revisited and examined with linear transient theory. Because the ground motion during earthquakes is not only transient but also consists of random horizontal and vertical motions, it is proper to treat hydrodynamic pressure on dams with transient theory for random, transient earthquake motions. The present study fines that surface waves are negligible and that the present theory agrees well with the classical theory if the ground motion is horizontal and harmonic with a high frequency.

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