The Experts below are selected from a list of 846 Experts worldwide ranked by ideXlab platform

Bingda Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Multi-Rate Real-Time Simulation Method Based on the Norton Equivalent
    Energies, 2020
    Co-Authors: Junjie Zhu, Bingda Zhang
    Abstract:

    For the problem of poor accuracy of the existing multi-rate simulation methods, this paper proposes a multi-rate real-time simulation method based on the Norton Equivalent, compared with multi-rate simulation method based on the ideal source Equivalent. After the Norton equivalence of the fast subsystem and the slow subsystem are established, they are solved simultaneously at the junction nodes. In order to reduce the amount of the simulation calculation, the Norton Equivalent circuit is obtained by incremental calculation. The data interaction between the fast subsystem and the slow subsystem is realized by extrapolation method. For ensuring the real-time performance of the simulation, the method of the slow subsystem calculates ahead of the fast subsystem is given for the slow subsystem with a large amount of calculation. Finally, the AC/DC hybrid power system was simulated on the real-time simulation platform (FPGA-based Real-Time Digital Solver, FRTDS), and the simulation results were compared with the single-rate simulation, which verified the correctness and accuracy of the proposed method.

  • Multi-Rate Real-Time Simulation Method Based on the Norton Equivalent
    2020
    Co-Authors: Junjie Zhu, Bingda Zhang
    Abstract:

    For the problem of poor accuracy of the existing multi-rate simulation methods, this paper proposes a multi rate real-time simulation method based on the Norton Equivalent, compared with multi-rate simulation method based on the ideal source Equivalent. After the Norton equivalence of the fast subsystem and the slow subsystem, they are obtained simultaneously at the junction nodes. In order to reduce the amount of simulation calculation, the Norton Equivalent circuit is obtained by incremental calculation. The data interface between the fast subsystem and the slow subsystem is realized by extrapolation method. For ensuring the real-time performance of the simulation, the method that the slow subsystem calculates ahead of the fast subsystem is given for the slow subsystem with a large amount of calculation. Finally, the AC/DC hybrid power system was simulated on the real-time simulation platform (FRTDS), and the simulation results were compared with the single-rate simulation, which verified the correctness and accuracy of the method.

  • Electromagnetic Transient-Transient Stability Analysis Hybrid Real-Time Simulation Method of Variable Area of Interest
    Energies, 2018
    Co-Authors: Bingda Zhang, Shipei Nie, Zhao Jin
    Abstract:

    To make the object of electromagnetic transient (EMT) simulation flexible to change, the authors propose using the method of electromagnetic transient-transient stability analysis (TSA) hybrid real-time simulation of the variable area of interest. The area where the fault is to be set, or where the operation takes place, is defined as the area of interest. The simulation object is divided into multiple sub-networks. The EMT simulation range is determined according to the voltage drop depth at the boundary of the adjacent sub-network caused by the three-phase short-circuit fault at the boundary of an area of interest. The Norton Equivalent is obtained by using the sub-network as a basic unit. The electromagnetic sub-network forms its own Norton Equivalent on the TSA side by means of the Norton Equivalent admittance of its TSA model. Based on this, the overall framework of hybrid real-time simulation of the variable area of interest is constructed. The fundamental phasor prediction and Norton Equivalent current source prediction are adopted to reduce the interface error. The performance of the proposed method in terms of feasibility, flexibility, and effectiveness have been verified by the simulation studies on the IEEE 118-bus system.

John D. Cressler - One of the best experts on this subject based on the ideXlab platform.

  • ISCAS - Systematic methodology for applying Mason's signal flow graph to analysis of feedback circuits
    2014 IEEE International Symposium on Circuits and Systems (ISCAS), 2014
    Co-Authors: Seungwoo Jung, Ickhyun Song, John D. Cressler
    Abstract:

    This paper introduces a systematic methodology for applying Mason's signal flow graph to the analysis of feedback circuits. We demonstrate that the relationships among signals of feedback circuits can be represented in a intuitive and graphical manner utilizing signal flow graphs. Once constructed, the desired solutions can be achieved by simple inspection of the signal flow graph. The Thevenin and Norton Equivalent circuits are utilized to model the loading effects of the feedback network in the example circuits presented.

Juan C. Gutiérrez - One of the best experts on this subject based on the ideXlab platform.

  • Fast transients analysis of nonuniform transmission lines through the method of characteristics
    International Journal of Electrical Power & Energy Systems, 2002
    Co-Authors: José A. Gutiérrez, Pablo Moreno, J.l. Naredo, Juan C. Gutiérrez
    Abstract:

    A new method for the simulation of fast transients on nonuniform transmission lines is proposed in this paper. The method is based on the method of characteristics of partial differential equations theory. It is shown that the proposed method can easily include resistive losses and wave speed variations. In addition, in order to bring the proposed method to practical usefulness, a Norton Equivalent for transmission line ends is presented. At any given time, the Norton Equivalent of each transmission line end is independent of the line's interior behavior at that time, therefore the model can readily be included into any electrical network transients simulation program. The advantages of the method are shown here by applying them to two problems. The first one consists of analyzing the effects of nonuniformities caused by the sagging of conductors on an aerial line. For this case, results from electromagnetic transients program and finite differences time domain simulations are included for comparison purposes. The second application consists of the simulation of a fast impulse propagating along a transmission tower modeled as a network of vertical and horizontal transmission lines.

Alessandro Garufo - One of the best experts on this subject based on the ideXlab platform.

  • Norton Equivalent circuit for pulsed photoconductive antennas part i theoretical model
    IEEE Transactions on Antennas and Propagation, 2018
    Co-Authors: Alessandro Garufo, Giorgio Carluccio, Nuria Llombart, A Neto
    Abstract:

    A novel Equivalent circuit for pulsed photoconductive sources is introduced for describing the coupling between the photoconductive gap and the antenna. The proposed circuit effectively describes the mechanism of feeding the antenna by the semiconductor when this latter is illuminated by a laser operating in a pulsed mode. Starting from the classical continuity equation, which models the free carriers’ density with respect to the laser power pump and the semiconductor features, a Norton Equivalent circuit in the frequency domain is derived. According to the Norton theorem, the Equivalent source representation is decoupled from the antenna. In particular, for photoconductive antennas (PCAs), the Norton circuit takes into account of the electrical and optical properties of the semiconductor material, the features of the laser excitation, as well as the geometrical dimensions of the gap. The presence of the electrodes around the gap is part of the antenna and, therefore, it is taken into account in the antenna impedance. The proposed circuit allows the analysis of the coupling between the photoconductive source and the antenna, providing a tool to analyze and design PCAs.

  • Norton Equivalent Circuit for Pulsed Photoconductive Antennas–Part I: Theoretical Model
    IEEE Transactions on Antennas and Propagation, 2018
    Co-Authors: Alessandro Garufo, Giorgio Carluccio, Nuria Llombart, Andrea Neto
    Abstract:

    A novel Equivalent circuit for pulsed photoconductive sources is introduced for describing the coupling between the photoconductive gap and the antenna. The proposed circuit effectively describes the mechanism of feeding the antenna by the semiconductor when this latter is illuminated by a laser operating in a pulsed mode. Starting from the classical continuity equation, which models the free carriers’ density with respect to the laser power pump and the semiconductor features, a Norton Equivalent circuit in the frequency domain is derived. According to the Norton theorem, the Equivalent source representation is decoupled from the antenna. In particular, for photoconductive antennas (PCAs), the Norton circuit takes into account of the electrical and optical properties of the semiconductor material, the features of the laser excitation, as well as the geometrical dimensions of the gap. The presence of the electrodes around the gap is part of the antenna and, therefore, it is taken into account in the antenna impedance. The proposed circuit allows the analysis of the coupling between the photoconductive source and the antenna, providing a tool to analyze and design PCAs.

  • Norton Equivalent circuit for pulsed photoconductive antennas part ii experimental validation
    IEEE Transactions on Antennas and Propagation, 2018
    Co-Authors: Alessandro Garufo, Giorgio Carluccio, Joshua R. Freeman, David R. Bacon, Nuria Llombart, Edmund H. Linfield, Alexander Giles Davies, A Neto
    Abstract:

    This second part of two papers’ sequence presents the experimental validation of the Norton Equivalent circuit model for pulsed photoconductive antennas (PCAs) provided in the first paper of the sequence. To this goal, different prototypes of photoconductive antenna sources have been manufactured and assembled. The average powers radiated and their pertinent energy spectral densities have been measured. In order to obtain a validation of the original Equivalent circuit proposed, an auxiliary electromagnetic analysis of the complete setup, including the quasi-optical (QO) link for the signals from the antenna feeds to the detectors had to be developed. By using the combined theoretical model (circuit and quasi-optics), an excellent agreement is achieved between the measured power and the power estimated. This agreement fully validates the circuit model, which can now be used to design new PCAs, including optical and electrical features of the semiconductor materials, as well as the details of the antenna gaps and the purely QO components.

  • Norton Equivalent Circuit for Pulsed Photoconductive Antennas—Part II: Experimental Validation
    IEEE Transactions on Antennas and Propagation, 2018
    Co-Authors: Alessandro Garufo, Giorgio Carluccio, Joshua R. Freeman, David R. Bacon, Nuria Llombart, Edmund H. Linfield, Alexander Giles Davies, Andrea Neto
    Abstract:

    This second part of two papers’ sequence presents the experimental validation of the Norton Equivalent circuit model for pulsed photoconductive antennas (PCAs) provided in the first paper of the sequence. To this goal, different prototypes of photoconductive antenna sources have been manufactured and assembled. The average powers radiated and their pertinent energy spectral densities have been measured. In order to obtain a validation of the original Equivalent circuit proposed, an auxiliary electromagnetic analysis of the complete setup, including the quasi-optical (QO) link for the signals from the antenna feeds to the detectors had to be developed. By using the combined theoretical model (circuit and quasi-optics), an excellent agreement is achieved between the measured power and the power estimated. This agreement fully validates the circuit model, which can now be used to design new PCAs, including optical and electrical features of the semiconductor materials, as well as the details of the antenna gaps and the purely QO components.

  • Analysis of photoconductive antenna power radiation by Norton Equivalent circuit
    2017 47th European Microwave Conference (EuMC), 2017
    Co-Authors: Alessandro Garufo, Giorgio Carluccio, Nuria Llombart Juan, Andrea Neto, Ioan E. Lager
    Abstract:

    A novel Norton Equivalent circuit model for characterizing the photoconductive feed of photoconductive antennas is introduced. It incorporates the physics of the photoconductive antenna's excitation by accounting for: (i) the electrical properties of the photoconductive material; (ii) the features of the optical power excitation; (iii) the geometrical dimensions of the gap between the electrodes that couple the antenna to the photoconductive material. The model is applicable to describing the antenna feeding mechanism for the photoconductors being illuminated by means of lasers operating in both pulsed and continuous modes. The proposed model is validated by comparing the power estimated by it with power measurements of different photoconductive antennas. The advocated solution is conducive to analyzing and designing photoconductive antennas. In particular, it is expected to be at the core of antenna optimization tools for maximizing the Terahertz (THz) power radiation, this making it an important enabler for designing THz time-domain systems.

Junjie Zhu - One of the best experts on this subject based on the ideXlab platform.

  • Multi-Rate Real-Time Simulation Method Based on the Norton Equivalent
    Energies, 2020
    Co-Authors: Junjie Zhu, Bingda Zhang
    Abstract:

    For the problem of poor accuracy of the existing multi-rate simulation methods, this paper proposes a multi-rate real-time simulation method based on the Norton Equivalent, compared with multi-rate simulation method based on the ideal source Equivalent. After the Norton equivalence of the fast subsystem and the slow subsystem are established, they are solved simultaneously at the junction nodes. In order to reduce the amount of the simulation calculation, the Norton Equivalent circuit is obtained by incremental calculation. The data interaction between the fast subsystem and the slow subsystem is realized by extrapolation method. For ensuring the real-time performance of the simulation, the method of the slow subsystem calculates ahead of the fast subsystem is given for the slow subsystem with a large amount of calculation. Finally, the AC/DC hybrid power system was simulated on the real-time simulation platform (FPGA-based Real-Time Digital Solver, FRTDS), and the simulation results were compared with the single-rate simulation, which verified the correctness and accuracy of the proposed method.

  • Multi-Rate Real-Time Simulation Method Based on the Norton Equivalent
    2020
    Co-Authors: Junjie Zhu, Bingda Zhang
    Abstract:

    For the problem of poor accuracy of the existing multi-rate simulation methods, this paper proposes a multi rate real-time simulation method based on the Norton Equivalent, compared with multi-rate simulation method based on the ideal source Equivalent. After the Norton equivalence of the fast subsystem and the slow subsystem, they are obtained simultaneously at the junction nodes. In order to reduce the amount of simulation calculation, the Norton Equivalent circuit is obtained by incremental calculation. The data interface between the fast subsystem and the slow subsystem is realized by extrapolation method. For ensuring the real-time performance of the simulation, the method that the slow subsystem calculates ahead of the fast subsystem is given for the slow subsystem with a large amount of calculation. Finally, the AC/DC hybrid power system was simulated on the real-time simulation platform (FRTDS), and the simulation results were compared with the single-rate simulation, which verified the correctness and accuracy of the method.