• Title/Summary/Keyword: Fundamental Circuit

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Algorithm for Fault Location Estimation on Transmission Lines using Second-order Difference of a Positive Sequence Current Phasor

  • Yeo, Sang-Min;Jang, Won-Hyeok;Kim, Chul-Hwan
    • Journal of Electrical Engineering and Technology
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    • v.8 no.3
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    • pp.499-506
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    • 2013
  • The accurate estimation of a fault location is desired in distance protection schemes for transmission lines in order to selectively deactivate a faulted line. However, a typical method to estimate a fault location by calculating impedances with voltages and currents at relaying points may have errors due to various factors such as the mutual impedances of lines, fault impedances, or effects of parallel circuits. The proposed algorithm in this paper begins by extracting the fundamental phasor of the positive sequence currents from the three phase currents. The second-order difference of the phasor is then calculated based on the fundamental phasor of positive sequence currents. The traveling times of the waves generated by a fault are derived from the second-order difference of the phasor. Finally, the distance from the relaying point to the fault is estimated using the traveling times. To analyze the performance of the algorithm, a power system with EHV(Extra High Voltage) untransposed double-circuit transmission lines is modeled and simulated under various fault conditions, such as several fault types, fault locations, and fault inception angles. The results of the simulations show that the proposed algorithm has the capability to estimate the fault locations with high speed and accuracy.

Embodiment of living body measure system modelling for rehalibitation treatment of positive simulation for HRV algorithm analysis interface of Mobile base (모바일기반의 HRV 인터페이스에 처리에 대한 생체계측 시스템 모델링의 구현)

  • Kim, Whi-Young
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.1013-1014
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    • 2006
  • Mobilecomputer offers more fundamental role than role assistance enemy of modern technology equipment and new Information Technology can reconsider, and reconstruct creatively accuracy of physiological concept. That military register symptoms are developed of disease, before far before rehalibitation, offer possibility that can intervene in process that motive change of military register symptoms after rehalibitation. But, that many parameters become analysis target and mathematical settlement and equalization system of neted data of that is huge, same time collection of all datas can lift difficulty etc.. These main weakness puts in structural relation between elements that compose system. Therefore, dynamics research that time urea of systematic adjustment has selected method code Tuesday nerve dynamics enemy who groping of approach that become analysis point is proper and do with recycling bioelectricity signal. Nature model of do living body signal digital analysis chapter as research result could be developed and scientific foundation groping could apply HSS (Hardware-software system) by rehalibitation purpose. Special quality that is done radish form Tuesday of bioelectricity signal formation furthermore studied, and by the result, fundamental process of bodysignal in do structure circuit form of analog - digital water supply height modelling do can

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Effect of Harmonics on Residual Current Protective Devices (고조파가 누전차단기에 미치는 영향)

  • Jeon, Jeong-Chay;Lee, Sang-Ick;Yoo, Jae-Geun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.3
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    • pp.84-89
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    • 2006
  • Tripping of residual current protective devices(RCPDs) caused by harmonics has been continuously reported, but no literature is available on the behavior of RCPDs caused by harmonics. This paper, in order to find out the effects of harmonics on RCPDs, investigated the present condition on malfunction of RCPDs and measured harmonics at buildings where nuisance tripping of RCPDs was often occurred. Also, the operational characteristics of RCPDs were tested by the harmonics synthesizer that can generate distorted waveform. Results of experiment detected that there was minimum tripping current of RCPDs when third harmonic added to the fundamental frequency. And it was found that the leakage current to cause tripping of RCPDs increased with more higher order harmonics added to the fundamental frequency.

A Semi-MMIC Hair-pin Resonator Oscillator for K-Band Application (K-Band용 SEmi-MMIC Hair-pin 공진발진기)

  • 이현태
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.9B
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    • pp.1635-1640
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    • 2000
  • In this paper, a 18 GHz oscillator is designed with the push-push method an fabricated by semi-MMIC process, in which the second harmonic is the main output signal with the suppressed fundamental mode. In semi-MMIC process, passive components with microstrip transmission line are implemented using MMIC process on semi-insulating GaAs substrate. Then, chip types of P-HEMT, resistors, and capacitors are connected through Au wire-bonding. Also, the ground plane is inserted around the circuit and connected each other with the back-side of substrate through Au wire-bonding instead of via-hole. The semi-MMIC push-push oscillator shows the output powder of -10.5 dBm, the fundamental frequency suppression of -17.3 dBc/Hz, and the phase noise of -97.9 dBc/Hz at the offset frequency of 100 kHz.

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A Practical Synthesis Technique for Optimal Arithmetic Hardware based on Carry-Save-Adders (캐리-세이브 가산기에 기초한 연산 하드웨어 최적화를 위한 실질적 합성 기법)

  • Kim, Tae-Hwan;Eom, Jun-Hyeong
    • Journal of KIISE:Computer Systems and Theory
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    • v.28 no.10
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    • pp.520-529
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    • 2001
  • Carry-save-adder(CSA) is one of the most effective operation cells in implementing an arithmetic hardware with high performace and small circuit area. An fundamental drawback of the existing CAS applications is that the applications are limited to the local parts of arithmetic circuit that are directly converted to additions. To resolve the limitation, we propose a set of new CSA transformation techniques: optimizing arithmetics with multiplexors, optimizing arithmetics in multiple designs, and optimizing arithmetics with multiplications. We then design a new CSA transformation algorithm which integrates the proposed techniques, so that we are able to utilize CSAs more globally. An extensive experimentation for practical designs are provided to show the effectiveness of our proposed algorithm over the conventional CSA techniques.

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Loss analysis for the novel half bridge inverter with load free-wheeling mode (부하 환류모드를 제공하는 새로운 반 브리지 인버터의 손실해석)

  • Yeon, Jae-Eul;Cho, Kyu-Min;Kim, Hee-Jun
    • Proceedings of the KIEE Conference
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    • 2003.10b
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    • pp.216-219
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    • 2003
  • The resonant inverter is widely used for induction heating, electronic ballast and supersonic motor driving circuit. In the meantime, control techniques of PWM, PFM etc.. are mainly applied to control the output power of the resonant inverter. But, in the case of using the half bridge resonant inverter, it is difficult to control the output power by PWM, because its main circuit does not provide the load free-wheeling mode. Therefore, PAM or PFM was usually applied to control output power of half bridge resonant inverter. However, PAM needs a variable DC voltage source, which makes the system structure more complex. On the other hand, in case of PFM, efficiency is declined by operation with poor power factor. This paper Proposed the novel half bridge resonant inverter which can provide the load free-wheeling mode. Also its analysis results for PWM operation with unity fundamental power factor are Presented and compared with other resonant inverters using PWM and PFM.

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Fundamental Aspects of the Unbalance Condition for the Forces involved in Rail Gun Recoil

  • Banerjee, Arindam;Radcliffe, P.J.
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.3
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    • pp.317-324
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    • 2014
  • The forces involved in the firing of the electromagnetic rail gun may be analyzed from Amperian, Maxwellian and Einsteinian approaches. This paper discusses these different paradigms with regard to rail gun performance modeling relating to the generation and balance of the forces caused by the currents and their induced magnetic fields. Recent experimental work on model rail guns, where the armature is held static, shows very little recoil upon the rails, thereby indicating a possible violation of Newton's Third Law of Motion. Dynamic testing to show this violation, as suggested by the authors in an earlier paper, has inherent technical difficulties. A purpose-built finite element C/C++ simulator that models that suspended rail gun firing action shows a net force acting upon the entire rail gun system. A new effect in physics, universal in scope, is thus indicated: a current circulating in an asymmetric and rigid circuit causes a net force to act upon the circuit for the duration of the current. This conclusion following from computer simulation based upon Maxwellian electrodynamics as opposed to the more modern relativistic quantum electrodynamics needs to be supported by unambiguous experimental validation.

Analog Predistortion High Power Amplifier Using Novel Low Memory Matching Topology

  • Kim, Jang-Heon;Woo, Young-Yun;Cha, Jeong-Hyeon;Hong, Sung-Chul;Kim, Il-Du;Moon, Jung-Hwan;Kim, Jung-Joon;Kim, Bum-Man
    • Journal of electromagnetic engineering and science
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    • v.7 no.4
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    • pp.147-153
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    • 2007
  • This paper represents an analog predistortion linearizer for the high power amplifier with low memory effect. The high power amplifier is implemented using a 90-W peak envelope power(PEP) LDMOSFET at 2.14-GHz and an envelope short matching topology is applied at the active ports to minimize the memory effect. The analog predistortion circuit comprises the fundamental path and the cuber and quintic generating circuits, whose amplitudes and phases can be controlled independently. The predistortion circuit is tested for two-tone and wide-band code division multiple access(WCDMA) 4FA signals. For the WCDMA signal, the adjacent channel leakage ratios(ACLRs) at 5 MHz offset are improved by 12.4 dB at average output powers of 36 dBm and 42 dBm.

Time Dependent Degradation of Cell in Dye-Sensitized Solar Cell (염료 감응형 태양전지에서 시간의 경과에 따른 셀의 특성 저하 연구)

  • Seo, Hyun Woo;Kim, Ki Soo;Beak, Hyun Duk;Kim, Dong Min
    • Journal of Hydrogen and New Energy
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    • v.24 no.5
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    • pp.421-427
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    • 2013
  • We report on the time dependent degradation of cell in dye-sensitized solar cells (DSSC). The photovoltaic performance of DSSC over a period of time was investigated in liquid electrolyte based on triiodide/iodide during six days. It was found that the short circuit current density ($j_{sc}$) of the cell dropped from 9.9 to $7mA/cm^2$ while efficiency (${\eta}$) of the cell decreased from 4.4 to 3.3%. The parameters corresponding to fundamental electronic and ionic processes in a working DSSC are determined from the electrochemical impedance spectrascopy (EIS) at open-circuit potential ($V_{oc}$). EIS study of the DSSC in the this work showed that the electron life time ${\tau}_r$ and chemical capacitance $C_{\mu}$ decreased significantly after six days. It was correlated the $j_{sc}$ and efficiency decreased after six days.

Effect of Boron Concentration on the UV Photosensitivity of Silica Glass Film for Planar Lightwave Circuit (Boron 첨가량이 평면광회로용 실리카 박막의 UV 감광성에 미치는 영향)

  • Kwon Ki Youl;Cho Seung-Hyun;Shin Dong Wook;Song Kug-Hyun;Lee Nak Kyu;Na Kyoung Hwan
    • Journal of the Korean Ceramic Society
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    • v.41 no.11
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    • pp.826-833
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    • 2004
  • In this study, photosensitivity dynamics in SiO$_2$ glass with the composition similar to that of silica Planar Lightwave Circuit (PLC) devices was investigated as a fundamental study prior to the device fabrication. Silica bulk glasses with similar composition to the core layer of PLC devices were prepared with variable composition of B$_2$O$_3$. The photosensitivity in boron and germanium co-doped SiO$_2$ glass yields refractive index change $\Delta$n as high as 10$\^$-3/. However such index modulation disappeared after annealing. From the result of annealing experiment and W absorption / Raman spectra, we conclude the compaction model is applicable to our glass system.