• 한국정보통신학회논문지
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• 제7권7호
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• pp.1514-1519
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• 2003

본 논문은 Custom Power의 입력 전압 Sag 보상을 위해 사용되는 3상 PWM Boost AC-AC 컨버터의 정적특성 및 동적 특성의 모델링 및 해석을 다룬다. 특히 회로 DQ 변환 기법을 사용하여 기본파 영역에서 시스템의 특성을 모두 포함하는 등가회로를 구하고, 전압이득과 입력 역률에 대한 해석적인 결과를 도출한다. 또한, 제어의 관점에서 유용한 일정한 동작 점 하에서의 선형화 된 상태방정식을 구한다. 끝으로, PSIM 시뮬레이션을 통하여 제안된 등가회로 모델링과 해석이 타당함을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.938-940
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• 2004

With increased emphasis on non-conventional energy system and autonomous power generation, development of improved and appropriate generating system has assumed signification. This paper describes the performance analysis of 2-phase self-excited induction generators. The minimum capacitance of self-excited capacitor connected auxiliary winding is determined the suitable value using circuit equations of auxiliary winding. For the steady state analysis, the equivalent circuit of 2-phase induction generators is used as circuit modeling using the double-revolving field theory. The validity of designed generator system will be confirmed by experimental and computed results.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권2호
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• pp.73-73
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• 2004

Nowadays, one of the serious problems in KEPCO system is the larger fault current than the SCC(Short Circuit Capacity) of circuit breaker. There are many alternatives to reduce the increased fault current such as isolations of bus ties, enhancement of SCC of circuit breaker, applications of HVDC-BTB(Back to Back) and FCL(fault current limiter). However, these alternatives have some drawbacks in viewpoints of system stability and cost. As the superconductivity technology has been developed, the HTS-FCL(High Temperature Superconductor-Fault Current Limiter) can be one of the attractive alternatives to solve the fault current problem. Under this background, this paper presents the EMTDC model for resistive type HTS-FCL considering the nonlinear characteristic of final resistance value when quenching Phenomena occur.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권3호
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• pp.122-127
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• 2003

This paper presents a new time-stepping 3-D analysis method coupled with an external circuit with motion equation for dynamic transient analysis of induction machines. In this method, the magneto-motive force (MMF) generated by induced current is modeled as a passive source in the magnetic equivalent network. So, by using only scalar potential at each node, the method is able to analyze induction machines with faster computation time and less memory requirement than conventional numerical methods. Also, this method is capable of modeling the movement of the mover without the need for re-meshing and analyzing the time harmonics for dynamic characteristics. From comparisons between the results of the analysis and the experiments, it is verified that the proposed method is capable of estimating the torque, harmonic field, etc. as a function of time with superior accuracy.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1670-1676
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• 2014

This paper presents the modeling of Single Electron Transistor (SET) based on Physical model of a device and its equivalent circuit. The physical model is derived from Schrodinger equation. The wave function of the electrode is calculated using Hartree-Fock method and the quantum dot calculation is obtained from WKB approximation. The resulting wave functions are used to compute tunneling rates. From the tunneling rate the current is calculated. The equivalent circuit model discuss about the effect of capacitance on tunneling probability and free energy change. The parameters of equivalent circuit are extracted and optimized using genetic algorithm. The effect of tunneling probability, temperature variation effect on tunneling rate, coulomb blockade effect and current voltage characteristics are discussed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.79-80
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• 2005

In this paper, the circuit models of optical to electrical(O/E) characteristics of waveguide photodiode(WGPD) submodule are examined. Test structures of WGPD and WGPD submodule were fabricated and S21 parameter was measured to characterize the O/E conversion property. Valid circuit models were derived by RF circuit simulation and O/E characteristics were modeled to analyze the effects of model parameters on the WGPD submodule performances. Based on the results, it can be concluded that the suggested WGPD submodule model can explain the characteristics of the O/E conversion of WGPD submodule, where the parasitic components originated from ribbon bonding block crucially influence on the performance of WGPD submodule, are able to show more efficient property by making compact bonding structure. We propose an effective WGPD submodule bonding structure and it can ensure the 40Gbps operation of WGPD.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1162-1164
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• 2005

A Linear Induction Motor that generates the direct thrust directly, is widely used for the operation system of electrified railroad, elevation system, conveyer system, and so on. There are two analysis methode of linear induction motor characteristics. One is the electrical magnetic analyzing, the other is analyzing equivalent circuit. The electrical magnetic analyzing methode has available advantages to consider the physical condition. The equivalent circuit analyzing methode has the elementary methode in the system of vector control and over shoot situation. In this paper, It is used the dynamic characteristic analyzing methode that can calculate efficiently the end effect by using equivalent circuit methode in the operating linear induction motor system modeling and doing simulation of output characteristics of vector controller.

• Journal of Electrical Engineering and Technology
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• 제11권6호
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• pp.1664-1673
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• 2016

Lithium rechargeable cells are used in many industrial applications, because they have high energy density and high power density. For an effective use of these lithium cells, it is essential to build a reliable battery management system (BMS). Therefore, the state of charge (SOC) estimation is one of the most important techniques used in the BMS. An appropriate modeling of the battery characteristics and an accurate algorithm to correct the modeling errors in accordance with the simplified model are required for practical SOC estimation. In order to implement these issues, this approach presents the comparative analysis of the SOC estimation performance using equivalent electrical circuit modeling (EECM) and noise suppression technique (NST) in three representative $LiCoO_2/LiFePO_4/LiNiMnCoO_2$ cells extensively applied in electric vehicles (EVs), hybrid electric vehicles (HEVs) and energy storage system (ESS) applications. Depending on the difference between some EECMs according to the number of RC-ladders and NST, the SOC estimation performances based on the extended Kalman filter (EKF) algorithm are compared. Additionally, in order to increase the accuracy of the EECM of the $LiFePO_4$ cell, a minor loop trajectory for proper OCV parameterization is applied to the SOC estimation for the comparison of the performances among the compared to SOC estimation performance.

• 조명전기설비학회논문지
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• 제16권5호
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• pp.53-60
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• 2002

본 논문에서는 정전류 부하모델 교류 전기철도 AT 급전시스템을 회로망 해석법(Loop Equation Method)을 이용하여 실제 급전시스템과 유사하게 제약조건을 두고 여러 경우를 가정하여 모델링 하였다. 이 방법을 통해 앞으로 건설될 고속 전기철도 급전시스템의 전력품질에 영향을 줄 수 있는 전압강하에 주안점을 두고 정상급전의 경우뿐만 아니라 연장급전의 경우를 새롭게 확대 해석하였으며 이 결과를 동적 시뮬레이션 프로그램인 PSCAD /EMTDC를 이용하여 그 정확성과 실용성을 검증하였다. 또한 사례연구를 통해 전압 보상기를 설치하지 않는 경우와 STATCOM을 설치한 경우의 전압강하 보상효과를 PSCAD/EMTDC로 시뮬레이션 하여 검증하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.174-179
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• 2017

We designed the CMOS analog integrate and fire (I&F) neuron circuit for driving memristor based on resistive-switching random access memory (RRAM). And we fabricated the RRAM device that have $HfO_2$ switching layer using atomic layer deposition (ALD). The RRAM device has gradual set and reset characteristics. By spice modeling of the synaptic device, we performed circuit simulation of synaptic device and CMOS neuron circuit. The neuron circuit consists of a current mirror for spatial integration, a capacitor for temporal integration, two inverters for pulse generation, a refractory part, and finally a feedback part for learning of the RRAM. We emulated the spike-timing-dependent-plasticity (STDP) characteristic that is performed automatically by pre-synaptic pulse and feedback signal of the neuron circuit. By STDP characteristics, the synaptic weight, conductance of the RRAM, is changed without additional control circuit.