• Title/Summary/Keyword: 4 Port Equivalent Model

Search Result 11, Processing Time 0.027 seconds

Equivalent Circuit Model for Four Port Connector System (4포트 커넥터 시스템의 등가회로 변환에 관한 연구)

  • Shim, Min-Kyu;Kim, Jong-Min;Nah, Wan-Soo
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.6
    • /
    • pp.1105-1110
    • /
    • 2007
  • This paper describes an equivalent circuit modeling of 4-port connector system. A coupled transmission line was designed and fabricated, mimicking a 4-port connector system, and then S-parameters were measured using 4 port VNA (Vector Network Analyzer). The S-parameters from measurement and from Full-wave simulator coincided quite nice. By using these S parameters, an equivalent circuit parameters for a 4-port system was obtained. The time domain response from the equivalent circuit model matched to the signals, which was measured using TDR(Time Domain Reflectometry) meter. We were also convinced that there should be enough bandwidth to get a meaningful time domain result from Fourier inverse transformation of the S parameters. In addition, we applied the conversion algorithm to the 4-port connector system, which calculates the S-parameters of a 4 port system using the data from a 2-port VNA with the other ports open. Comparison of the two data, one from measurement and the other one from the conversion algorithm, was made in this manuscript.

S-Domain Equivalent System for Electromagnetic Transient Studies PART II : Frequency Dependent AC System Equivalent (전자기 과도현상 해석을 위한 S 영역 등가시스템 PART II: 주파수 의존 교류 시스템 등가)

  • Chung Hyeng-Hwan;Wang Yong-Peel
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.54 no.4
    • /
    • pp.165-171
    • /
    • 2005
  • Electromagnetic transient simulation can be used to model complex non-linearities that very difficult to represent adequately in the frequency domain. This problem is greatly reduced with the use of frequency dependent network equivalents for the linear part of the system. S-domain rational function fitting techniques for representing frequency dependent equivalents have been developed using Least Squares Fitting(LSF). However it does not suffer the implementation error that exited in this work as it ignored the instantaneous term. This paper presents the formulation for developing 2 port Frequency Dependent AC System Equivalent(FDACSE) with the instantaneous term in S-domain and illustrates its use. This 2 port FDNE have been applied to the New Zealand AC system. The electromagnetic transient package PSCAD/EMTDC is used to assess the transient response of the 2 port (FDACSE) developed with Norton Equivalent network. The study results have indicated the robustness and accuracy of 2 port FDACSE for electromagnetic transient studies.

Q measurement of two port RE cavity by scattering parameters (산란행렬에 의한 2단자망 RF 공동공진기의 Q 측정)

  • 한대현
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.4 no.4
    • /
    • pp.895-899
    • /
    • 2000
  • A method of measuring Q of a two port cavity by scattering parameters is proposed. The scattering parameters of a two port cavity resonator are derived by a lumped equivalent circuit model as a function of cavity parameters, including the cavity Q. These can be also obtained by direct measurement with a modern network analyzer, The results show good agreement with those from other well-known methods. This two port measurement can provide additional information such as the coupled power ratio, which is one of the important parameters for the beam accelerating cavities.

  • PDF

Perfectly-Matched DC Blocks Terminated in Arbitrary Impedances (임의의 종단 임피던스를 갖는 DC Block의 완전 정합)

  • Ahn, Hee-Ran;Kim, Bum-Man
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.18 no.8
    • /
    • pp.895-903
    • /
    • 2007
  • Design equations of DC blocks terminated in arbitrary impedances are newly suggested and a microstrip DC block is tested for the perfect matching. The DC block is a two-port passive component and the power excited at a port is transmitted into another port. However, all the excited power at the input can not be delivered to the output and therefore most of the conventional DC blocks can not be perfectly matched with arbitrary termination impedances. To solve the matching problem, its one-port equivalent resonant circuit model, front which design equations can be derived, is newly suggested. Using the derived design equations, any DC block can be designed, perfectly matched without any restriction of coupling coefficients. To verify the derived design equations, measurements were carried out and the results are in good agreement with prediction, showing insertion and return losses at 4.1 GHz are 0.82dB and -31dB, respectively.

A Study on Design of Broadband Electromagnetic Wave Absorber for Single Polarization (단일편파용 광대역 전파흡수체의 설계에 관한 연구)

  • 김동일;이수영;정세모
    • Journal of the Korean Institute of Navigation
    • /
    • v.19 no.4
    • /
    • pp.93-102
    • /
    • 1995
  • A design method of an electromagnetic wave absorber with ferrite fins in the second layer, which has very wide band frequency characteristics, is proposed and discussed. A theoretical model using the equivalent material constants method is adopted, assessed for its accuracy by comparision with the Hashin-Shtrikman formulas and compared with the conventional absorbers. Based on the model, a wide band electromagnetic wave absorber with excellent reflectivity frequency characteristics in frequency range of 30MHZ to 3530MHZ has been designed.

  • PDF

Power Decoupled Multi-Port Dual-Active-Bridge Converter Employing Multiple Transformers for DC Distribution Applications (복수의 변압기를 사용하여 독립 전력제어가 가능한 DC 배전용 다중포트 Dual-Active-Bridge 컨버터)

  • Kim, Inhyeok;Sim, Ju-Young;Lee, Jun-Young;Jung, Jee-Hoon
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.25 no.4
    • /
    • pp.286-292
    • /
    • 2020
  • This study proposes a power decoupled multi-port dual-active-bridge (DAB) DC-DC converter employing multiple transformers. Conventional multiport DAB DC-DC converters experience a power coupling issue from the use of a single transformer, which essentially requires complex power decoupling control. To solve this issue, a multiport DAB DC-DC converter employing multiple transformers is proposed to decouple output power without additional complex control algorithms. The proposed converter uses multiple transformers that can expand output ports easily. Therefore, transformers and the proposed multi-port DAB converter can be designed simply. In addition, the number of coupling inductors can be reduced in the proposed three-port DAB converter compared with that in conventional multiport DAB converters. The power decoupling characteristics and equivalent circuit of the proposed converter are analyzed using theoretical model approaches. Finally, a 3-kW laboratory prototype is developed to verify the effectiveness of the proposed converter.

The comparison and investigation of harmonic magnification according to power supply schemes in high speed railway (고속철도의 급전계통 구성에 따른 고조파 확대율 비교 검토)

  • Lee, Chang-Mu;Oh, Kwang-Hae;Chang, Sang-Hun
    • Proceedings of the KIEE Conference
    • /
    • 2000.07b
    • /
    • pp.1402-1404
    • /
    • 2000
  • The electrified railway has various power supply schemes. Although the identical trains are operated in same condition and the impedance of track are equal, the genealogy impedance of track is changed according to composition method of feeding scheme. So, the harmonic current flowing into the railway substation are greatly unlike. For simulation of harmonic magnification flowing into the railway substation according to feeding scheme, we propose 6-port network analysis method based on 4-port network, find 6-port equivalent model of each circuit component, and compare and investigate harmonic magnification in the case of parallel post and normal feeding scheme.

  • PDF

Analysis of Voltage Unbalance in the Electric Railway Depot Using Two-port Network Model (4단자 회로망 모델을 이용한 전기철도 차량기지의 전압불평형 해석)

  • Chang, Sang-Hoon;Oh, Kwang-Hae;Kim, Jung-Hoon
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.50 no.5
    • /
    • pp.248-254
    • /
    • 2001
  • The traction power demand highly varies with time and train positions and the traction load is a large-capacity current at single phase converted from 3-phase power system. Subsequently, each phase current converted from 3-phase power system cannot be maintained in balance any longer and thus the traction load can bring about imbalance in three-phase voltage. Therefore, the exact assessment of voltage unbalance must be carried out preferentially as well as load forecast at stages of designing and planning for electric railway system. The evaluation of unbalance voltage in areas, such as electric railway depots should be a prerequisite with more accuracy. The conventional researches on voltage unbalance have dealt with connection schemes of the transformers used in ac AT-fed electric railroads system and induced formulas to briefly evaluate voltage unbalance in the system(3). These formulas are still being used widely due to their easy applicabilities on voltage unbalance evaluation. Meanwhile, they don't take into account detailed characteristics of ac AT-fed electric railroads system, being founded on some assumptions. Accordingly. accuracy still remains in question. This paper proposes a new method to more effectively estimate voltage unbalance index. In this method, numerous diverted circuits in electric railway depots are categorized in three components and each component is defined as a two-port network model. The equivalent circuit for the entire power supply system is also described into a two-port network model by making parallel and/or series connections of these components. Efficiency and accuracy in voltage unbalance calculation as well can be promoted by simplifying the circuits into two-port network models.

  • PDF

Computer Simulation and Modeling of Cushioning Pneumatic Cylinder (공기압 실린더의 쿠션특성에 관한 모델링 및 컴퓨터 시뮬레이션)

  • 이상천
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.23 no.6
    • /
    • pp.794-805
    • /
    • 1999
  • Pneumatic cushioning cylinders are commonly employed for vibration and shock control. A mathematical simulation model of a double acting pneumatic cushioning cylinder designed to absorb shock loads is presented which is based on the following assumptions; ideal equation of state isentropic flow through a port conservation of mass polytropic thermodynamics single degree of freedom piston dynamics and energy equivalent linear damping. These differential equation can be solved through numerical integration using the fourth order Runge-Kutta method. An experimental study was conducted to validate the results obtained by the numerical integra-tion technique. Simulated results show good agreement with experimental data. The computer simulation model presented here has been extremely useful not only in understanding the has been extremely useful not only in understanding the basic cushioning but also in evaluating different designs.

  • PDF

An Empirical Comparison and Verification Study on the Containerports Clustering Measurement Using K-Means and Hierarchical Clustering(Average Linkage Method Using Cross-Efficiency Metrics, and Ward Method) and Mixed Models (K-Means 군집모형과 계층적 군집(교차효율성 메트릭스에 의한 평균연결법, Ward법)모형 및 혼합모형을 이용한 컨테이너항만의 클러스터링 측정에 대한 실증적 비교 및 검증에 관한 연구)

  • Park, Ro-Kyung
    • Journal of Korea Port Economic Association
    • /
    • v.34 no.3
    • /
    • pp.17-52
    • /
    • 2018
  • The purpose of this paper is to measure the clustering change and analyze empirical results. Additionally, by using k-means, hierarchical, and mixed models on Asian container ports over the period 2006-2015, the study aims to form a cluster comprising Busan, Incheon, and Gwangyang ports. The models consider the number of cranes, depth, birth length, and total area as inputs and container twenty-foot equivalent units(TEU) as output. Following are the main empirical results. First, ranking order according to the increasing ratio during the 10 years analysis shows that the value for average linkage(AL), mixed ward, rule of thumb(RT)& elbow, ward, and mixed AL are 42.04% up, 35.01% up, 30.47%up, and 23.65% up, respectively. Second, according to the RT and elbow models, the three Korean ports can be clustered with Asian ports in the following manner: Busan Port(Hong Kong, Guangzhou, Qingdao, and Singapore), Incheon Port(Tokyo, Nagoya, Osaka, Manila, and Bangkok), and Gwangyang Port(Gungzhou, Ningbo, Qingdao, and Kasiung). Third, optimal clustering numbers are as follows: AL(6), Mixed Ward(5), RT&elbow(4), Ward(5), and Mixed AL(6). Fourth, empirical clustering results match with those of questionnaire-Busan Port(80%), Incheon Port(17%), and Gwangyang Port(50%). The policy implication is that related parties of Korean seaports should introduce port improvement plans like the benchmarking of clustered seaports.