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Articles 1 - 16 of 16
Full-Text Articles in Engineering
Rate Of Change Of Direct-Axis Current Component Protection Scheme For Inverter-Based Islanded Microgrids, Abdolhamid Farshadi, Behzad Keyvani Eydi, Hamed Nafisi, Hossein Askarian-Abyaneh, Arash Beiranvand
Rate Of Change Of Direct-Axis Current Component Protection Scheme For Inverter-Based Islanded Microgrids, Abdolhamid Farshadi, Behzad Keyvani Eydi, Hamed Nafisi, Hossein Askarian-Abyaneh, Arash Beiranvand
Articles
Rapid growth in the utilization of the inverter-interfaced distributed energy resources (IIDERs) in microgrids has brought new challenges in the network protection area. Microgrid protection specifically becomes a concern during operation in the islanded mode. There is a considerable reduction in fault current levels in this mode compared to when the microgrid is connected to the grid, which makes conventional algorithms operate with significant delay or, in many cases, not even pick up the fault. This paper proposes a protection algorithm based on the rate of change of direct-axis current component ( id ) to protect inverter-based microgrids (IBMGs). The …
On Finding An Equivalent Force To Mimic The Multilayer Ceramic Capacitor Vibration, Yifan Ding, Jianmin Zhang, Mingfeng Xue, Shengyin Ding, Benjamin Leung, Eric A. Macintosh, Chulsoon Hwang
On Finding An Equivalent Force To Mimic The Multilayer Ceramic Capacitor Vibration, Yifan Ding, Jianmin Zhang, Mingfeng Xue, Shengyin Ding, Benjamin Leung, Eric A. Macintosh, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
The Multilayer Ceramic Capacitor (MLCC) Can Vibrate Due to the Piezoelectric Effect When There is AC Noise on the Power Rail. the Vibration of the Capacitor Will Generate a Force on the PCB and Thus Cause the PCB Vibration and Audible Problems May Occur. the Work in This Paper Finds an Equivalent Force with Similar Behavior to the MLCC-Generated Force. the Force is Controllable and Knowable and Thus Can Mimic the Capacitor Vibration on the PCB.
Equivalent Force Extraction Methodology For Electrical Component Induced Pcb Vibration, Yifan Ding, Jianmin Zhang, Ming Feng Xue, Xin Hua, Benjamin Leung, Eric A. Macintosh, Chulsoon Hwang
Equivalent Force Extraction Methodology For Electrical Component Induced Pcb Vibration, Yifan Ding, Jianmin Zhang, Ming Feng Xue, Xin Hua, Benjamin Leung, Eric A. Macintosh, Chulsoon Hwang
Electrical and Computer Engineering Faculty Research & Creative Works
On-board electrical components can cause printed circuit board (PCB) vibration, thus generating audio noise if the electrical noise is in the audible frequency range. The electrical component-induced vibration can be equated to an external force applied to the PCB. This article presents a novel methodology to extract the equivalent force of electrical components on a PCB to study board vibration and potential acoustic noise problems. The method is based on a combination of measurement and simulation, wherein PCB vibration is used as the medium in the extraction process. The methodology is validated by the correlation of PCB vibration pattern, frequency, …
Dipole-Moment-Based Reciprocity For Practical Desensitization Identification And Mitigation, Shengxuan Xia, Hanfeng Wang, Yansheng Wang, Zhonghua Wu, Chulsoon Hwang, Jun Fan
Dipole-Moment-Based Reciprocity For Practical Desensitization Identification And Mitigation, Shengxuan Xia, Hanfeng Wang, Yansheng Wang, Zhonghua Wu, Chulsoon Hwang, Jun Fan
Electrical and Computer Engineering Faculty Research & Creative Works
Radio frequency interference can degrade the receiving sensitivity of antennas. The interference is usually caused by certain coupling structures, such as layouts without adequate grounding for the radio frequency signal return path. Those structures can be modeled as a set of equivalent dipole moments when they are electrically small. Herein, the dipole moment model-based coupling framework is applied to a practical cellphone design case to devise an engineering solution. The coupling framework incorporates dipole moments as radiation sources and a coupling model based on the reciprocity theorem. Unfortunately, near-field scan probes often lack access to all locations, owing to the …
An Extended Generalized Average Modeling Framework For Power Converters, Kartikeya Jayadurga Prasad Veeramraju, Jacob A. Mueller, Jonathan W. Kimball
An Extended Generalized Average Modeling Framework For Power Converters, Kartikeya Jayadurga Prasad Veeramraju, Jacob A. Mueller, Jonathan W. Kimball
Electrical and Computer Engineering Faculty Research & Creative Works
The Generalized Averaged Modeling (GAM) technique is traditionally employed to capture the dynamic performance of power electronic converters. This paper proposes an improved version of it, named the Extended-GAM (EGAM) technique, which supports the multiplication of two Double Fourier Series (DFS) signals in the time domain. Multiplication of DFS signals in the time domain translates to the 2D-convolution of coefficients of the DFS terms of their equivalent Discrete Fourier Image (DFI) representations. Thus, the proposed EGAM technique, capable of capturing many harmonics present in the output of a power converter, effectively captures the dynamic behavior of power converters excited by …
Experimental Evaluation Of A 63.3:1 Dual-Stage Coaxial Magnetic Gear, Hossein Baninajar, Sina Modaresahmadi, H. Y. Wong, Jonathan Bird, W. Williams, B. Dechant
Experimental Evaluation Of A 63.3:1 Dual-Stage Coaxial Magnetic Gear, Hossein Baninajar, Sina Modaresahmadi, H. Y. Wong, Jonathan Bird, W. Williams, B. Dechant
Electrical and Computer Engineering Faculty Publications and Presentations
This paper presents the construction and testing results for a 63.3:1 dual-stage coaxial magnetic gear for use in a marine hydrokinetic generator demonstrator application. The dual-stage magnetic gear is composed of series-connected coaxial magnetic gear. The stage-2 magnetic gear utilizes Halbach magnet arrays on both rotors and has a 9.5:1 gear ratio. The stage-1 magnetic gear utilizes a Halbach rotor on the outer rotor and a flux concentration inner rotor. The stage-1 magnetic gear has a 6.67:1 gear ratio and at the peak torque of 1220Nm the stage-1 MG was shown to be capable of operating with a 268 N·m/L …
Designing A Halbach Rotor Magnetic Gear For A Marine Hydrokinetic Generator, Hossein Baninajar, Sina Modaresahmadi, H. Y. Wong, Jonathan Bird, W. Williams, B. Dechant
Designing A Halbach Rotor Magnetic Gear For A Marine Hydrokinetic Generator, Hossein Baninajar, Sina Modaresahmadi, H. Y. Wong, Jonathan Bird, W. Williams, B. Dechant
Electrical and Computer Engineering Faculty Publications and Presentations
This paper presents the electromagnetic and mechanical design as well as experimental testing results for a 9.5:1 gear ratio, series connected, coaxial magnetic gear (MG) for use in a marine hydrokinetic generator. A 2-D and 3-D magnetostatic finite element analysis (FEA) sizing analysis was also conducted and a torque density comparison between using a nested or series MG typology is presented. To achieve a high torque density a four-segment per pole-pair Halbach rotor assembly with a unique slotted Halbach magnet arrangement was used that enables the Halbach rotor magnets to be more easily assembled, even with dimensional tolerance inaccuracies. A …
A Practical Simulation Flow For Singing Capacitor Based Acoustic Noise Analysis, Xin Yan, Songping Wu, Mingfeng Xue, Chi Kin Benjamin Leung, Daryl G. Beetner, Jianmin Zhang
A Practical Simulation Flow For Singing Capacitor Based Acoustic Noise Analysis, Xin Yan, Songping Wu, Mingfeng Xue, Chi Kin Benjamin Leung, Daryl G. Beetner, Jianmin Zhang
Electrical and Computer Engineering Faculty Research & Creative Works
Multilayer ceramic capacitors (MLCCs) are widely used in modern electronics. Due to the piezoelectric effect of the ceramic material, however, MLCCs subjected to electrical noise may vibrate and generate acoustic noise, as 'singing'. Acoustic noise can be annoying for users, especially within mobile devices, so it becomes important to perform acoustic noise analysis before a product is released. In this paper, a practical simulation flow for singing capacitor based acoustic noise is presented. The simulation flow and analysis method are developed on Ansys Sherlock and Mechanical. In Ansys Sherlock, local library and Approved Vendor List (AVL) files were used to …
Phasor Domain Modeling Of Type-Iii Wind Turbines, Mohammed Alqahtani
Phasor Domain Modeling Of Type-Iii Wind Turbines, Mohammed Alqahtani
USF Tampa Graduate Theses and Dissertations
This dissertation research focuses on developing an accurate steady-state phasor model for Doubly Fed Induction Generator (DFIG)-based wind turbines (Type-III WTs). Unlike the classical synchronous or asynchronous generators, Type-III WTs are electronically coupled to the power grid. The steady-state and dynamic responses of the DFIG-based WTs depend on the behavior of the converters controllers. Accurate modeling requires reproducing the behavior of the power electronics and the control system for various operating scenarios. The analysis of this research area is carried out in two stages or tasks. The first task focuses on the balanced stator voltage situation, while the unbalanced stator …
Designing A Continuously Variable Magnetic Gear, J. Pritchard, Pavithra Padmanathan, Jonathan Z. Bird
Designing A Continuously Variable Magnetic Gear, J. Pritchard, Pavithra Padmanathan, Jonathan Z. Bird
Electrical and Computer Engineering Faculty Publications and Presentations
This paper investigates the performance capabilities of a continuously variable magnetic gearbox that utilizes a flux focusing rotor structure. A fractional slot stator winding is designed to couple to the outer rotor of an existing magnetic gearbox in order to enable the magnetic gearbox to operate with a variable gear ratio.
Calculation Of Magnet Losses In Concentrated-Winding Permanent-Magnet Synchronous Machines Using A Computationally Efficient Finite-Element Method, Peng Zhang, Gennadi Y. Sizov, Jiangbiao He, Dan M. Ionel, Nabeel Demerdash
Calculation Of Magnet Losses In Concentrated-Winding Permanent-Magnet Synchronous Machines Using A Computationally Efficient Finite-Element Method, Peng Zhang, Gennadi Y. Sizov, Jiangbiao He, Dan M. Ionel, Nabeel Demerdash
Electrical and Computer Engineering Faculty Research and Publications
The proposed hybrid method combines computationally efficient finite-element analysis (CE-FEA) with a new analytical formulation for eddy-current losses in the permanent magnets (PMs) of sine-wave current-regulated brushless synchronous motors. The CE-FEA only employs a reduced set of magnetostatic solutions yielding substantial reductions in the computational time, as compared with the conventional FEA. The 3-D end effects and the effect of pulsewidth-modulation switching harmonics are incorporated in the analytical calculations. The algorithms are applied to two fractional-slot concentrated-winding interior PM motors with different circumferential and axial PM block segmentation arrangements. The method is validated against 2-D and 3-D time-stepping FEA.
A New Placement And Integration Method Of Upqc To Improve The Power Quality In Dg Network, Shafiuzzaman K. Khadem, Malabika Basu, Michael Conlon
A New Placement And Integration Method Of Upqc To Improve The Power Quality In Dg Network, Shafiuzzaman K. Khadem, Malabika Basu, Michael Conlon
Conference papers
A new proposal for the placement and integration of UPQC in DG connected microgrid/micro generation (μG) system has been presented here. DG converters (with storage), the load and shunt part of the UPQC will be placed at or after the PCC. The series part of the UPQC will be placed before the PCC and in series with the grid. DC link can be connected to the storage system also. Hence, it is termed UPQCμG. The advantages of the proposed UPQCμG over the normal UPQC are to compensate voltage interruptions in addition to voltage sags / swells, harmonic …
Modeling And Parametric Design Of Permanent-Magnet Ac Machines Using Computationally Efficient Finite-Element Analysis, Gennadi Y. Sizov, Dan M. Ionel, Nabeel Demerdash
Modeling And Parametric Design Of Permanent-Magnet Ac Machines Using Computationally Efficient Finite-Element Analysis, Gennadi Y. Sizov, Dan M. Ionel, Nabeel Demerdash
Electrical and Computer Engineering Faculty Research and Publications
Computationally efficient finite-element analysis (FEA) (CE-FEA) fully exploits the symmetries of electric and magnetic circuits of sine-wave current-regulated synchronous machines and yields substantial savings of computational efforts. Motor performance is evaluated through Fourier analysis and a minimum number of magnetostatic solutions. The major steady-state performance indices (average torque, ripple and cogging torque, back-electromotive-force waveforms, and core losses) are satisfactorily estimated as compared with the results of detailed time-stepping (transient) FEA. In this paper, the CE-FEA method is presented and applied to a parametric design study for an interior-permanent-magnet machine. Significant reduction of simulation times is achieved (approximately two orders of …
Intelligent Tool For Determining The True Harmonic Current Contribution Of A Customer In A Power Distribution Network, Joy Mazumdar, Ronald G. Harley, Frank C. Lambert, Ganesh K. Venayagamoorthy, Marty L. Page
Intelligent Tool For Determining The True Harmonic Current Contribution Of A Customer In A Power Distribution Network, Joy Mazumdar, Ronald G. Harley, Frank C. Lambert, Ganesh K. Venayagamoorthy, Marty L. Page
Electrical and Computer Engineering Faculty Research & Creative Works
Customer loads connected to power distribution network may be broadly categorized as either linear or nonlinear. Nonlinear loads inject harmonics into the power network. Harmonics in a power system are classified as either load harmonics or as supply harmonics depending on their origin. The source impedance also impacts the harmonic current flowing in the network. Hence, any change in the source impedance is reflected in the harmonic spectrum of the current. This paper proposes a novel method based on artificial neural networks to isolate and evaluate the impact of the source impedance change without disrupting the operation of any load, …
Change In Voltage Distortion Predictions At The Pcc Due To Changing Nonlinear Load Current Profile Using Plant Startup Data, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley
Change In Voltage Distortion Predictions At The Pcc Due To Changing Nonlinear Load Current Profile Using Plant Startup Data, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley
Electrical and Computer Engineering Faculty Research & Creative Works
Customer loads connected to electricity supply systems may be broadly categorized as either linear or nonlinear. Nonlinear loads inject harmonics in a power distribution network. The interaction of the nonlinear load harmonics with the network impedances creates voltage distortions at the point of common coupling (PCC) which in turn affects other loads connected to the same PCC. When several nonlinear loads are connected to the PCC, it is difficult to predict mathematically how each nonlinear load is affecting the voltage distortion level at the PCC. Typically, customers with nonlinear loads apply harmonic filtering techniques to clean up their current and …
Unified Large And Small Signal Discrete-Space Modeling For Pwm Converters In Ccm, Ehab Hamed Shoubaki
Unified Large And Small Signal Discrete-Space Modeling For Pwm Converters In Ccm, Ehab Hamed Shoubaki
Electronic Theses and Dissertations
In this Thesis a Unified Discrete State-Space Model for power converters in CCM is presented. Two main approaches to arriving at the discrete model are used. The first approach involves an impulse function approximation of the duty cycle modulations of the converter switches , and this approach results in a small signal discrete model. The Second approach is direct and does not involve any approximation of the modulations , this approach yields both a large signal nonlinear discrete model and a linear small signal model. Harmonic analysis of the converter states at steady-state is done for steady-state waveform acquisition , …