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Full-Text Articles in Engineering
Application Of Tvs Models For Seed Simulation Of A Variety Of Tvs Devices, Li Shen, Yang Xu, Steffen Holland, Sergej Bub, David Pommerenke, Daryl G. Beetner
Application Of Tvs Models For Seed Simulation Of A Variety Of Tvs Devices, Li Shen, Yang Xu, Steffen Holland, Sergej Bub, David Pommerenke, Daryl G. Beetner
Electrical and Computer Engineering Faculty Research & Creative Works
Accurate Models of Transient Voltage Suppression (TVS) Devices Are Important for Determining the Suitability of Electrostatic Discharge (ESD) Protection Strategies Early in the Design Process. an Improved TVS Model is Used in the Following Paper to Represent a Variety of TVS Devices, Including a Snapback Device, Non-Snapback Device, and a Varistor. the Models Include Recent Improvements to Represent Conductivity Modulation and the overall Shape of the TVS Device's Transient Response. the Models Are Tuned based on Characterizations of These Protection Devices using a Transmission Line Pulse (TLP) and Are Then Used in a System Efficient ESD Design (SEED) Simulation to …
Modeling And Simulation Of Microgrid, Ahmad Alzahrani, Mehdi Ferdowsi, Pourya Shamsi, Cihan H. Dagli
Modeling And Simulation Of Microgrid, Ahmad Alzahrani, Mehdi Ferdowsi, Pourya Shamsi, Cihan H. Dagli
Electrical and Computer Engineering Faculty Research & Creative Works
Complex computer systems and electric power grids share many properties of how they behave and how they are structured. A microgrid is a smaller electric grid that contains several homes, energy storage units, and distributed generators. The main idea behind microgrids is the ability to work even if the main grid is not supplying power. That is, the energy storage unit and distributed generation will supply power in that case, and if there is excess in power production from renewable energy sources, it will go to the energy storage unit. Therefore, the electric grid becomes decentralized in terms of control …
Computational Modeling And Experimental Study On Optical Microresonators Using Optimal Spherical Structure For Chemical Sensing, Hanzheng Wang, Lei Yuan, Jie Huang, Xinwei Lan, Cheol-Woon Kim, Lan Jiang, Hai Xiao
Computational Modeling And Experimental Study On Optical Microresonators Using Optimal Spherical Structure For Chemical Sensing, Hanzheng Wang, Lei Yuan, Jie Huang, Xinwei Lan, Cheol-Woon Kim, Lan Jiang, Hai Xiao
Electrical and Computer Engineering Faculty Research & Creative Works
Chemical sensors based on optical microresonators have been demonstrated highly sensitive by monitoring the refractive index (RI) changes in the surrounding area near the resonator surface. In an optical resonator, the Whispering Gallery Modes (WGMs) with high quality (Q) factor supported by the spherical symmetric structure interacts with the contiguous background through evanescent field. Highly sensitive detection can be realized because of the long lifetime of the photons. The computational models of solid glass microspheres and hollow glass spheres with porous wall (PW-HGM) were established. These two types of microresonators were studied through simulations. The PWHGM resonator was proved as …
Frequency-Domain Measurement Method For The Analysis Of Esd Generators And Coupling, Jayong Koo, Qing Cai, Giorgi Muchaidze, Andrew Martwick, Kai Wang, David Pommerenke
Frequency-Domain Measurement Method For The Analysis Of Esd Generators And Coupling, Jayong Koo, Qing Cai, Giorgi Muchaidze, Andrew Martwick, Kai Wang, David Pommerenke
Electrical and Computer Engineering Faculty Research & Creative Works
A method for analyzing electrostatic discharge (ESD) generators and coupling to equipment under test in the frequency domain is proposed. In ESD generators, the pulses are excited by the voltage collapse across relay contacts. The voltage collapse is replaced by one port of a vector network analyer (VNA). All the discrete and structural elements that form the ESD current pulse and the transient fields are excited by the VNA as if they were excited by the voltage collapse. In such a way, the method allows analyzing the current and field-driven linear coupling without having to discharge an ESD generator, eliminating …
Simulation Model For Assessing Transient Performance Of Capacitive Voltage Transformers, I. Sule, Ganesh K. Venayagamoorthy, U. O. Aliyu
Simulation Model For Assessing Transient Performance Of Capacitive Voltage Transformers, I. Sule, Ganesh K. Venayagamoorthy, U. O. Aliyu
Electrical and Computer Engineering Faculty Research & Creative Works
In determining the correct operation of relays of a protection scheme, proper representation of instrument transformers and their behavior in conditions where there can be transient is very critical. This paper presents a simulation model for assessing the transient performance of capacitive voltage transformers (CVTs). In order to test the validity of the developed model, four CVT operational conditions are considered using field data collected from one of the Nigerian electric utility 330/132/33 kV substations. The model simulation results revealed various configuration performance responses that could affect relay protection schemes to different degrees. As expected, the CVT responses showed that …
Pulse Regulation Control Technique For Integrated High-Quality Rectifier-Regulators, Mehdi Ferdowsi, Ali Emadi
Pulse Regulation Control Technique For Integrated High-Quality Rectifier-Regulators, Mehdi Ferdowsi, Ali Emadi
Electrical and Computer Engineering Faculty Research & Creative Works
The pulse regulation control scheme is presented and applied to the boost integrated flyback rectifier/energy storage dc/dc (BIFRED) converter as the most popular member of the integrated high-quality rectifier-regulators (IHQRR). In contrast to the conventional control techniques, the principal idea of pulse regulation is to regulate the output voltage using a series of high- and low-power pulses generated by the current of the input inductor, which is operating in discontinuous conduction mode (DCM). Analysis of the BIFRED converter operating in DCM is presented. Fundamentals of pulse regulation as well as its stability analysis and the estimation of the output voltage …
Modeling Yield Of Carbon-Nanotube/Silicon-Nanowire Fet-Based Nanoarray Architecture With H-Hot Addressing Scheme, Shanrui Zhang, Minsu Choi, Nohpill Park
Modeling Yield Of Carbon-Nanotube/Silicon-Nanowire Fet-Based Nanoarray Architecture With H-Hot Addressing Scheme, Shanrui Zhang, Minsu Choi, Nohpill Park
Electrical and Computer Engineering Faculty Research & Creative Works
With molecular-scale materials, devices and fabrication techniques recently being developed, high-density computing systems in the nanometer domain emerge. An array-based nanoarchitecture has been recently proposed based on nanowires such as carbon nanotubes (CNTs) and silicon nanowires (SiNWs). High-density nanoarray-based systems consisting of nanometer-scale elements are likely to have many imperfections; thus, defect-tolerance is considered one of the most significant challenges. In this paper we propose a probabilistic yield model for the array-based nanoarchitecture. The proposed yield model can be used (1) to accurately estimate the raw and net array densities, and (2) to design and optimize more defect and fault-tolerant …
An Extrapolation Procedure To Shorten Time Domain Simulations, Giuseppe Selli, James L. Drewniak, David Pommerenke
An Extrapolation Procedure To Shorten Time Domain Simulations, Giuseppe Selli, James L. Drewniak, David Pommerenke
Electrical and Computer Engineering Faculty Research & Creative Works
Time-domain simulation algorithms are widely used in the anaylsis and design of electromagnetic systems. Many of them are characterized by high Q's. Thus, the simulations have to employ many time steps in order to achieve a complete characterization of these systems. This time-consuming computational effort can be avoided if the late instants of time are extrapolated by applying a parametric estimation algorithm. An optimized implementation of a time-domain extrapolation method and a stop criterion are discussed in this paper. The latter criterion is based upon a normalized squared difference between the waveforms extrapolated from two different sets of initial data …
Modeling Issues For Full-Wave Numerical Emi Simulation, Michael A. Cracraft, Xiaoning Ye, Chen Wang, Sandeep K. R. Chandra, James L. Drewniak
Modeling Issues For Full-Wave Numerical Emi Simulation, Michael A. Cracraft, Xiaoning Ye, Chen Wang, Sandeep K. R. Chandra, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
In electromagnetic modeling, agreement between modeling and measurements is a common goal. There are questions that define every model. What is to be modeled? How is it going to be modeled? At what scale is it to be modeled? Through sample results and discussion, this paper addresses some general and some specific elements of model veracity. Through determination, numerical models can certainly be pushed to match any measured results. However, in the end the question that this paper addresses is not necessarily "How good can this model be?" as it is "Is this model good enough?".
Fdtd Method Capable Of Attaching Rectangular Domains, Kai Xiao, David Pommerenke, James L. Drewniak
Fdtd Method Capable Of Attaching Rectangular Domains, Kai Xiao, David Pommerenke, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
A finite-difference time-domain (FDTD) method capable of attaching rectangular computational domains is proposed herein. The aim of this approach is to reduce the size of computational domain according to the geometry of the modeled structure so as to reduce the simulation time with keeping precision of the result in an acceptable range. A multigrid algorithm is applied on the attaching interface between two rectangular domains so that different resolution can be achieved in different domains.
An Industrial Food Processing Plant Automation Using A Hybrid Of Pi And Fuzzy Logic Control, Ganesh K. Venayagamoorthy, D. Naidoo, P. Govender
An Industrial Food Processing Plant Automation Using A Hybrid Of Pi And Fuzzy Logic Control, Ganesh K. Venayagamoorthy, D. Naidoo, P. Govender
Electrical and Computer Engineering Faculty Research & Creative Works
An industrial food processing plant consisting of nonlinear dynamics requires pressure and temperature controllers to be nonlinear. In this paper, nonlinear controllers are designed using fuzzy logic to augment the conventional pressure and temperature PI controllers for an industrial food processing plant. Simulation results are presented to show improvement in the plant response with the hybrid controllers.
Simulation Studies With A Continuously Online Trained Artificial Neural Network Controller For A Micro-Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley
Simulation Studies With A Continuously Online Trained Artificial Neural Network Controller For A Micro-Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley
Electrical and Computer Engineering Faculty Research & Creative Works
This paper reports on the simulation studies carried out using MATLAB/SIMULINK and the practical implementation of a continuously online trained (COT) artificial neural network (ANN) controller to identify the continuous changing complex nonlinear dynamics of the power system, and another COT ANN to control a micro-turbogenerator which consists of a turbine simulator and a micro-alternator connected to an infinite bus through a short transmission line in a laboratory environment. This neural network controller augments/replaces the traditional automatic voltage regulator (AVR) and the turbine governor of the generator. Simulation and practical results are presented to show that this COT ANN identifier/controller …
Fdtd Modeling Of Thin Wires For Simulating Common-Mode Radiation From Structures With Attached Cables, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren
Fdtd Modeling Of Thin Wires For Simulating Common-Mode Radiation From Structures With Attached Cables, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
The analysis of shielding enclosures is complicated by the existence of apertures and cables. The finite-difference time-domain (FDTD) method can model shielding enclosures with complex geometries, but has difficulty modeling wires and cables of arbitrary radii. Modeling the wire by setting the axial component of the electric field to zero in the FDTD results in a wire with a radius determined by the mesh discretisation. Neglecting wire radius in applications such as electromagnetic interference (EMI) or printed circuit board modeling may result in gross errors because near field quantities are typically sensitive to wire thickness. Taflove (1990) developed a wire …
Analysis Of A Current-Regulated Brushless Dc Drive, Keith Corzine, S. D. Sudhoff, H. J. Hegner
Analysis Of A Current-Regulated Brushless Dc Drive, Keith Corzine, S. D. Sudhoff, H. J. Hegner
Electrical and Computer Engineering Faculty Research & Creative Works
Current-regulated brushless DC machines are used in a wide variety of applications including robotics, actuators, electric vehicles, and ship propulsion systems. When conducting system analysis of this or any other type of drive, average-value reduced-order models are invaluable since they provide a means of rapidly predicting the electromechanical dynamics and are readily linearized for control system synthesis. In this paper, a highly accurate average-value reduced-order model of a hysteresis current-regulated brushless DC drive is set forth. In so doing it is demonstrated that the drive exhibits five distinct operating modes. The physical cause of each of these modes is explained …
A Flux-Weakening Strategy For Current-Regulated Surface-Mounted Permanent-Magnet Machine Drives, Keith Corzine, S. D. Sudhoff, H. J. Hegner
A Flux-Weakening Strategy For Current-Regulated Surface-Mounted Permanent-Magnet Machine Drives, Keith Corzine, S. D. Sudhoff, H. J. Hegner
Electrical and Computer Engineering Faculty Research & Creative Works
Permanent-magnet synchronous machines fed from current-regulated converters feature nearly ideal performance at low-to-moderate speeds. However, as rotor speed increases the back emf rises which results in loss of current regulation and decreased torque. In buried-magnet machine drives, flux weakening is often used to extend the speed range. This paper sets forth a flux-weakening control specifically designed for surface-mounted permanent-magnet machines which is simple and does not require knowledge of the machine or system parameters. The proposed method is demonstrated both experimentally and through the use of computer simulation
The Multirate Method For Simulation Of Power System Dynamics, J. G. Chen, Mariesa Crow
The Multirate Method For Simulation Of Power System Dynamics, J. G. Chen, Mariesa Crow
Electrical and Computer Engineering Faculty Research & Creative Works
In this paper, the multirate method is introduced to analyse power system behavior for systems with widely varying time constants. Estimates for computational speed-up are derived based on a linear system approach. The method is applied to a small power system example and the results, both in terms of accuracy and computation time, are compared to traditional simulation methods