• Title/Summary/Keyword: frequency simulation

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Equivalent Circuit Model of RF passive components based on its simulated frequency response data (EM Solver 의 주파수 응답 데이터를 이용한 RF 수동 소자의 등가회로 모델링에 관한 연구)

  • Oh, Sang-Bae;Ko, Jae-Hyeong;Han, Hyeong-Seok;Kim, Hyeong-Seok
    • 한국정보통신설비학회:학술대회논문집
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    • 2007.08a
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    • pp.27-30
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    • 2007
  • This paper deals with an equivalent circuit model for RF passive components. Rational functions are obtained from the frequency responses of EM simulation by using Foster canonical partial fraction expressions. The Vector Fitting(VF) and the Adaptive Frequency Sampling(AFS) scheme are also implemented to obtain the rational functions. A passivity enforcement algorithm is applied to ensure the stability of the equivalent circuit model. In order to verify the schemes, S parameters of the equivalent circuit model is compared to those of EM simulation in case of the microstrip line structure with 3 slots in ground.

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A Study on the UPFC Dynamic Simulation Algorithm for Low Frequency Oscillation Studies (저주파 진동 해석을 위한 UPFC의 동적 시뮬레이션 알고리즘에 관한 연구)

  • Son, Kwang-Myoung
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.49 no.10
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    • pp.502-508
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    • 2000
  • This paper presents a dynamic simulation algorithm for studying the effect of United Power Flow Controller(UPFC) on the low frequency power system oscillations and transient stability studies. The proposed algorithm is a Newton-type one and uses current injection type UPFC model, which gives a fast convergence characteristics. The algorithm is applied to studying inter-area power oscillation damping enhancement of a sample two-area power system both in time domain and frequency domain. The case study results show that the proposed algorithm is very efficient and UPFC is very effective and robust against operating point change.

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A Numerical Study of the Effect of Casting Temperature and Rotational Frequency of Mold on the Functionally Graded Microstructure in Centrifugal Casting of Hyper-eutectic Al-Si Alloy (과공정 Al-Si합금의 원심주조시 용탕온도와 금형회전수가 경사기능 조직에 미치는 영향에 대한 해석적 고찰)

  • Park, Jeong-Wook;Kim, Heon-Joo
    • Journal of Korea Foundry Society
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    • v.29 no.2
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    • pp.78-85
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    • 2009
  • Functionally graded microstructure of centrifugal cast Al-Si alloy, especially distribution of primary Si particles according to the changes of melt pouring temperature and rotation frequency was investigated by numerical simulation. Moving velocity of Si particles increased as the melt pouring temperature and rotational frequency of mold increased. Therefore, segregation tendency of primary Si particles toward inner side of cylindrical sample increased as the melt pouring temperature and rotational frequency of mold increased. Rich distribution region of particles was located at 0.9, 0.7, 0.4 mm from inner surface of cylindrical sample under the centrifugal cast condition of $750^{\circ}C$ melt pouring temperature and 1500, 2000 and 2500 rpm mold rotational frequencies, respectively, by numerical simulation.

Particle-in-Cell Simulation for the Control of Electron Energy Probability & Electron temperature of Dielectric Barrier Discharges at Atmospheric Pressure

  • Lee, Jung-Yel;Song, In-Cheol;Lee, Ho-Jun;Lee, Hae-June
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.528-528
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    • 2012
  • Recently, atmospheric pressure plasmas attract lots of interests for the useful applications such as surface modification and bio-medical treatment. In this study, a particle-in-cell Monte Carlo collision (PIC-MCC) simulation was adopted to investigate the discharge characteristics of a planar micro dielectric barrier discharge (DBD) with a driving frequency from 13.56 MHz to 162.72 MHz and with a gap distance of 80 micrometers. The variation of frequency, in the change in the electron energy probability function (EEPF). Through the relation between the ion trajectories and the frequency, results in the change of EEPFs is achievable with the turning point of frequency mode. Therefore, it is possible to categorize the efficient operation range of DBDs for its applications by controlling the interactions between plasmas and neutral gas for the generation of preferable radicals.

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Optimization Study on the Epitaxial Structure for 100nm-Gate MHEMTs with InAlAs/InGaAs/GaAs Heterostructure (InAlAs/InGaAs/GaAs 100 nm-게이트 MHEMT 소자의 에피 구조 최적화 설계에 관한 연구)

  • Son, Myung-Sik
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.4
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    • pp.107-112
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    • 2011
  • This paper is for improving the RF frequency performance of a fabricated 100nm ${\Gamma}$-gate MHEMT, scaling down vertically for the epitaxy-structure layers of the device. Hydrodynamic simulation parameters are calibrated for the fabricated MHEMT with the modulation-doped $In_{0.52}Al_{0.48}As/In_{0.53}Ga_{0.47}$As heterostructure grown on the GaAs substrate. With these calibrated parameters, simulations for the vertically-scaled epitaxial layers of the device are performed and analyzed for DC/RF characteristics, including the quantization effect due to the thickness reduction of InGaAs channel layer. A newly designed epitaxy-structure device shows higher extrinsic transconductance, $g_m$ of 1.556 S/mm, and higher frequency performance, $f_T$ of 222.5 GHz and $f_{max}$ of 849.6 GHz.

3kW multi-string photovoltaic inverter design and simulation (3kW 멀티스트링 태양광 인버터 설계 및 시뮬레이션)

  • Lee, Jong-In;Yu, Beyng-Gyu;Yu, Gwen-Jong;Kim, Heung-Geun
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.371-376
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    • 2009
  • The Power Conditioning System is Power Transfer System which make array DC current to the Grid sinusoidal current. These are Low Frequency Transformer Inverter Type, High Frequency Transformer Inverter Type and Transformer-less Type. Low Frequency Transformer Type has a Excellent Isolation property, but doesn't have competitiveness in Size and Cost. Also High Frequency Transformer Type has a good Isolation property but there are many steps in Power transfer Switching. Nowadays, Transformer-less Type inverter change a transformer to DC/DC Converter which is small and cost effective. In this paper shown the DC/DC Converter Transformer-less Type multi-string inverter design and simulation. The Control Algorithm will be introduced and Simulation was accomplished.

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FPGA Implementation of Frequency Offset Cancel Circuit using CORDIC in OFDM (CORDIC을 이용한 OFDM 시스템의 주파수 옵셋 제거 회로의 FPGA 구현)

  • Byon, Kun-Sik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.5
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    • pp.906-911
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    • 2008
  • This paper designed Simulik Model to cancel the carrier frequency offset in OFDM using CORDIC Algorithm and evaluated its performance. And Simulink Model compared with Xilinx System Generator Model for FPGA implementation. As a result of simulation, we confirmed that both model is error free by CORDIC when offset frequency is lower than $10^5MHz$. Also, we verified the performance through Hardware Co-simulation with Xilinx Spartan3 xc3s1000 fg676-4 Target Device, and timing analysis and resource estimation.

Analysis of Dynamic Characteristics of Hydraulic Transmission Lines with Distributed Parameter Model (분포정수계 유압관로 모델의 동특성 해석)

  • Kim, Do Tae
    • Journal of Drive and Control
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    • v.15 no.4
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    • pp.67-73
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    • 2018
  • The paper deals with an approach to time domain simulation for closed end at the downstream of pipe, hydraulic lines terminating into a tank and series lines with change of cross sectional area. Time domain simulation of a fluid power systems containing hydraulic lines is very complex and difficult if the transfer functions consist of hyperbolic Bessel functions which is the case for the distributed parameter dissipative model. In this paper, the magnitudes and phases of the complex transfer functions of hydraulic lines are calculated, and the MATLAB Toolbox is used to formulate a rational polynomial approximation for these transfer functions in the frequency domain. The approximated transfer functions are accurate over a designated frequency range, and used to analyze the time domain response. This approach is usefully to simulate fluid power systems with hydraulic lines without to approximate the frequency dependent viscous friction.

Numerical Method for Computing the Resonant Frequencies and Q-factor in Microwave Dielectric Resonator

  • Kim, Nam-young;Yoo, Hojoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.245-248
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    • 1997
  • The dielectric resonators(DRs) with dielectric properties are widely used in microwave integrated circuit(MICs) and monolithic microwave integrated circuits(MMICS). The variational method as numerical simulation scheme would be applied to calculate the resonant frequencies(fr) and Q-factors of microwave dielectric resonators. The dielectric resonator with a cylindrical “puck” structure of high dielectric material is modeled in this simulation. The parameters, such as the diameter, the height, and the dielectric constant of dielectric resonator, would determine the resonant frequency and the Q-factor. The relationship between these parameters would effect each other to evaluate the approximate resonant frequency. This simulation method by the variational formula is very effective to calculate fr, and Q-factor. in high frequency microwave dielectric resonator The error rate of the simulation results and the measured results would be considered to design the microwave dielectric resonators.

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Transient Simulation Studies of Squirrel-Cage Induction Motor Directly Supplied with Aircraft Variable Frequency Power

  • Du, Xiaofei;Wang, Deqiang;Zhou, Yuanjun
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.1
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    • pp.7-14
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    • 2014
  • Aircraft variable frequency power and a new application of induction motor under the aero-power are introduced. The transient models and simulation of induction motor are reviewed. A new transient model and simulation method is presented that includes deep-bar effect and magnetic saturation. Dynamic magnetizing inductance, rotor resistance and leakage reactance are considered as varying parameters in state-space model. Base on known rotor structure and speed, these parameters can be calculated.