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You searched for subject:(passive component minimization). Showing records 1 – 3 of 3 total matches.

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Virginia Tech

1. Zhang, Di. Analysis and Design of Paralleled Three-Phase Voltage Source Converters with Interleaving.

Degree: PhD, Electrical and Computer Engineering, 2010, Virginia Tech

Three-phase voltage source converters(VSCs) have become the converter of choice in many ac medium and high power applications due to their many advantages, including low harmonics, high power factor, and high efficiency. Modular VSCs have also been a popular choice as building blocks to achieve even higher power, primarily through converter paralleling. In addition to high power ratings, paralleling converters can also provide system redundancy through the so-called (N+1) configuration for improved availability, as well as allow easy implementation of converter power management. Interleaving can further improve the benefit of paralleling VSCs by reducing system harmonic currents, which potentially can increase system power density. There are many challenges to implement interleaving in paralleled VSCs system due to the complicated relationships in a three-phase power converter system. In addition, to maximize the benefit of interleaving, current knowledge of symmetric interleaving is not enough. More insightful understanding of this PWM technology is necessary before implement interleaving in a real paralleled VSCs system. In this dissertation, a systematic methodology to analyze and design a paralleled three-phase voltage source converters with interleaving is developed. All the analysis and proposed control methods are investigated with the goal of maximizing the benefit of interleaving based on system requirement. The dissertation is divided into five sections. Firstly, a complete analysis studying the impact of interleaving on harmonic currents in ac and dc side passive components for paralleled VSCs is presented. The analysis performed considers the effects of modulation index, pulse-width-modulation (PWM) schemes, interleaving angle and displacement angle. Based on the analysis the method to optimize interleaving angle is proposed. Secondly, the control methods for the common mode (CM) circulating current of paralleled three-phase VSCs with discontinuous space-vector modulation (DPWM) and interleaving are proposed. With the control methods, DPWM and interleaving, which is a desirable combination, but not considered possible, can be implemented together. In addition, the total flux of integrated inter-phase inductor to limit circulating current can be minimized. Thirdly, a 15 kW three phase ac-dc rectifier is built with SiC devices. With the technologies presented in this dissertation, the specific power density can be pushed more than 2kW/lb. Fourthly, the converter system with low switching frequency is studied. Special issues such as beat phenomenon and system unbalance due to non-triplen carrier ratio is explained and solved by control methods. Other than that, an improved asymmetric space vector modulation is proposed, which can significantly reduce output current total harmonic distortion (THD) for single and interleaved VSCs system. Finally, the method to protect a system with paralleled VSCs under the occurrence of internal faults is studied. After the internal fault is detected and isolated,… Advisors/Committee Members: Centeno, Virgilio A. (committee member), Leech, Irene E. (committee member), De La Ree Lopez, Jaime (committee member), Boroyevich, Dushan (committeecochair), Wang, Fei Fred (committeecochair).

Subjects/Keywords: passive component minimization; high power density; Asymmetric interleaving angle; harmonic current reduction; Asymmetric SVM; Interleaving; THD reduction; failure mode analysis

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Zhang, D. (2010). Analysis and Design of Paralleled Three-Phase Voltage Source Converters with Interleaving. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/27579

Chicago Manual of Style (16th Edition):

Zhang, Di. “Analysis and Design of Paralleled Three-Phase Voltage Source Converters with Interleaving.” 2010. Doctoral Dissertation, Virginia Tech. Accessed April 22, 2019. http://hdl.handle.net/10919/27579.

MLA Handbook (7th Edition):

Zhang, Di. “Analysis and Design of Paralleled Three-Phase Voltage Source Converters with Interleaving.” 2010. Web. 22 Apr 2019.

Vancouver:

Zhang D. Analysis and Design of Paralleled Three-Phase Voltage Source Converters with Interleaving. [Internet] [Doctoral dissertation]. Virginia Tech; 2010. [cited 2019 Apr 22]. Available from: http://hdl.handle.net/10919/27579.

Council of Science Editors:

Zhang D. Analysis and Design of Paralleled Three-Phase Voltage Source Converters with Interleaving. [Doctoral Dissertation]. Virginia Tech; 2010. Available from: http://hdl.handle.net/10919/27579


Virginia Tech

2. Zhang, Xuning. Passive Component Weight Reduction for Three Phase Power Converters.

Degree: PhD, Electrical and Computer Engineering, 2014, Virginia Tech

Over the past ten years, there has been increased use of electronic power processing in alternative, sustainable, and distributed energy sources, as well as energy storage systems, transportation systems, and the power grid. Three-phase voltage source converters (VSCs) have become the converter of choice in many ac medium- and high-power applications due to their many advantages, such as high efficiency and fast response. For transportation applications, high power density is the key design target, since increasing power density can reduce fuel consumption and increase the total system efficiency. While power electronics devices have greatly improved the efficiency, overall performance and power density of power converters, using power electronic devices also introduces EMI issues to the system, which means filters are inevitable in those systems, and they make up a significant portion of the total system size and cost. Thus, designing for high power density for both power converters and passive components, especially filters, becomes the key issue for three-phase converters. This dissertation explores two different approaches to reducing the EMI filter size. One approach focuses on the EMI filters itself, including using advanced EMI filter structures to improve filter performance and modifying the EMI filter design method to avoid overdesign. The second approach focuses on reducing the EMI noise generated from the converter using a three-level and/or interleaving topology and changing the modulation and control methods to reduce the noise source and reduce the weight and size of the filters. This dissertation is divided into five chapters. Chapter 1 describes the motivations and objectives of this research. After an examination of the surveyed results from the literature, the challenges in this research area are addressed. Chapter 2 studies system-level EMI modeling and EMI filter design methods for voltage source converters. Filter-design-oriented EMI modeling methods are proposed to predict the EMI noise analytically. Based on these models, filter design procedures are improved to avoid overdesign using in-circuit attenuation (ICA) of the filters. The noise propagation path impedance is taken into consideration as part of a detailed discussion of the interaction between EMI filters, and the key design constraints of inductor implementation are presented. Based on the modeling, design and implementation methods, the impact of the switching frequency on EMI filter weight design is also examined. A two-level dc-fed motor drive system is used as an example, but the modeling and design methods can also be applied to other power converter systems. Chapter 3 presents the impact of the interleaving technique on reducing the system passive weight. Taking into consideration the system propagation path impedance, small-angle interleaving is studied, and an analytical calculation method is proposed to minimize the inductor value for interleaved systems. The design and integration of interphase inductors are also analyzed,… Advisors/Committee Members: Boroyevich, Dushan (committeechair), Stilwell, Daniel J. (committee member), Mattavelli, Paolo (committee member), Ngo, Khai D. (committee member), Lesko, John J. (committee member).

Subjects/Keywords: High power density; Passive component weight minimization; EMI modeling; EMI noise reduction; Filter design and optimization; Interleaving; Asymmetric interleaving angle; Interphase inductor; Multi-level converters; Interleaved three level topology.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Zhang, X. (2014). Passive Component Weight Reduction for Three Phase Power Converters. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/47788

Chicago Manual of Style (16th Edition):

Zhang, Xuning. “Passive Component Weight Reduction for Three Phase Power Converters.” 2014. Doctoral Dissertation, Virginia Tech. Accessed April 22, 2019. http://hdl.handle.net/10919/47788.

MLA Handbook (7th Edition):

Zhang, Xuning. “Passive Component Weight Reduction for Three Phase Power Converters.” 2014. Web. 22 Apr 2019.

Vancouver:

Zhang X. Passive Component Weight Reduction for Three Phase Power Converters. [Internet] [Doctoral dissertation]. Virginia Tech; 2014. [cited 2019 Apr 22]. Available from: http://hdl.handle.net/10919/47788.

Council of Science Editors:

Zhang X. Passive Component Weight Reduction for Three Phase Power Converters. [Doctoral Dissertation]. Virginia Tech; 2014. Available from: http://hdl.handle.net/10919/47788


Virginia Tech

3. Lai, Rixin. Analysis and Design for a High Power Density Three-Phase AC Converter Using SiC Devices.

Degree: PhD, Electrical and Computer Engineering, 2008, Virginia Tech

The development of high power density three-phase ac converter has been a hot topic in power electronics area due to the increasing needs in applications like electric vehicle, aircraft and aerospace, where light weight and/or low volume is usually a must. Many challenges exist due to the complicated correlations in a three-phase power converter system. In addition, with the emerging SiC device technology the operating frequency of the converter can be potentially pushed to the range from tens of kHz to hundreds of kHz at higher voltage and higher power conditions. The extended frequency range brings opportunities to further improve the power density of the converter. Technologies based on existing devices need to be revisited. In this dissertation, a systematic methodology to analyze and design the high power density three-phase ac converter is developed. All the key factors of the converter design are explored from the high density standpoint. Firstly, the criteria for the passive filter selection are derived and the relationship between the switching frequency and the size of the EMI filter is investigated. A function integration concept as well as the physical design approach is proposed. Secondly, a topology evaluation method is presented, which provides the insight into the relationships between the system constraints, operating conditions and design variables. Four topologies are then compared with the proposed approach culminating with a favored topology under the given conditions. Thirdly, a novel average model is developed for the selected topology, and used for devising a carrier-based control approach with simple calculation and good regulation performance. Fourthly, the converter failure mode operation and corresponding protection approaches are discussed and developed. Finally, a 10 kW three-phase ac/ac converter is built with the SiC devices. All the key concepts and ideas developed in this work are implemented in this hardware system and then verified by the experimental results. Advisors/Committee Members: Wang, Fei Fred (committeechair), Liu, Yilu (committee member), Lin, Tao (committee member), Burgos, Rolando (committee member), Boroyevich, Dushan (committee member).

Subjects/Keywords: passive component minimization; high performance control development; high power density; failure mode analysis; topology evaluation; SiC devices

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Lai, R. (2008). Analysis and Design for a High Power Density Three-Phase AC Converter Using SiC Devices. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/30155

Chicago Manual of Style (16th Edition):

Lai, Rixin. “Analysis and Design for a High Power Density Three-Phase AC Converter Using SiC Devices.” 2008. Doctoral Dissertation, Virginia Tech. Accessed April 22, 2019. http://hdl.handle.net/10919/30155.

MLA Handbook (7th Edition):

Lai, Rixin. “Analysis and Design for a High Power Density Three-Phase AC Converter Using SiC Devices.” 2008. Web. 22 Apr 2019.

Vancouver:

Lai R. Analysis and Design for a High Power Density Three-Phase AC Converter Using SiC Devices. [Internet] [Doctoral dissertation]. Virginia Tech; 2008. [cited 2019 Apr 22]. Available from: http://hdl.handle.net/10919/30155.

Council of Science Editors:

Lai R. Analysis and Design for a High Power Density Three-Phase AC Converter Using SiC Devices. [Doctoral Dissertation]. Virginia Tech; 2008. Available from: http://hdl.handle.net/10919/30155

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