High Frequency Isolated Single Stage Integrated Resonant Ac Dc Converters For Pmsg Based Wind Energy Conversion Systems

Download High Frequency Isolated Single Stage Integrated Resonant Ac Dc Converters For Pmsg Based Wind Energy Conversion Systems full books in PDF, epub, and Kindle. Read online High Frequency Isolated Single Stage Integrated Resonant Ac Dc Converters For Pmsg Based Wind Energy Conversion Systems ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!

High Frequency Isolated Single-Stage Integrated Resonant AC-DC Converters for PMSG Based Wind Energy Conversion Systems

Author : Yimian Du
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (88 download)

DOWNLOAD NOW!

Book Synopsis High Frequency Isolated Single-Stage Integrated Resonant AC-DC Converters for PMSG Based Wind Energy Conversion Systems by : Yimian Du

Download or read book High Frequency Isolated Single-Stage Integrated Resonant AC-DC Converters for PMSG Based Wind Energy Conversion Systems written by Yimian Du and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, two high-frequency (HF) transformer isolated single-stage integrated ac-dc converters are proposed for a small scale permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS). These two types of single-stage integrated ac-dc converters include expected functions of HF isolation, power factor correction (PFC), and output regulation in one single-stage. Fixed-frequency phase-shift control and soft-switching operation are employed in both proposed ac-dc converters. After reviewing the literature and discussing pros and cons of the existing topologies, it is preferred that three identical single-phase single-stage integrated converters with interleaved connection configuration are suitable for the PMSG. For the single-phase converter, two new HF isolated single-stage integrated resonant ac-dc converters with fixed-frequency phase-shift control are proposed. The first proposed circuit is HF isolated single-stage integrated secondary-side controlled ac-dc converter. The other proposed circuit is HF isolated single-stage dual-tank LCL-type series resonant ac-dc converter, which brings better solutions compared to the first converter, such as high power factor and low total harmonic distortion (THD) at the ac input side. Approximate analysis approach and Fourier series methods are used to analyze these two proposed converters. Design examples for each one are given and designed converters are simulated using PSIM simulation package. Two experimental circuits are also built to verify the analysis and simulation. The simulated and experimental results reasonably match the theoretical analysis. Then the proposed HF isolated dual-tank LCL-type series resonant ac-dc converter is used for three-phase interleaved connection in order to satisfy requirements of PMSG based WECS. A design example for this three-phase interleaved configuration is given and simulated for validation under several operating conditions.

High-frequency Isolated DC/AC and Bidirectional DC/DC Converters for PMSG-based Wind Turbine Generation System

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (68 download)

DOWNLOAD NOW!

Book Synopsis High-frequency Isolated DC/AC and Bidirectional DC/DC Converters for PMSG-based Wind Turbine Generation System by :

Download or read book High-frequency Isolated DC/AC and Bidirectional DC/DC Converters for PMSG-based Wind Turbine Generation System written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, a high-frequency (HF) transformer isolated grid-connected power converter system with battery backup function is proposed for a small-scale wind generation system (less than 100 kW) using permanent magnet synchronous generator (PMSG). The system includes a main HF isolated DC/AC grid-connected converter and a bidirectional HF isolated DC/DC converter. Through literature survey and some comparative studies, a HF isolated DC/DC converter followed by a line connected inverter (LCI) is chosen as the grid-connected scheme. After reviewing several topologies which were used in such a DC/AC converter with an unfolding stage, a DC/AC grid-connected converter based on dual- bridge LCL-type resonant topology is proposed. Through the control of the phase- shift angle between the two bridges, a rectified sinusoidal dc link current can be modulated, which in turn can be unfolded by the LCI. This converter is analyzed with Fourier series analysis approach. It is shown that all switches in both bridges can work in zero-voltage switching (ZVS) at any phase-shift and load conditions. The redundancy of the dual-bridge structure make it easy to accommodate higher power flow. A design example of a 500 W converter is given and simulated. A prototype is built and tested in the lab to validate its performance. The simulation and experimental results show a reasonable match to the theoretical analysis. The expansion to three-phase grid-connection is discussed with phase-shifted parallel operation of three identical units. Input and output current harmonics of different arrangements are analyzed to search for the best choice. As the feature of a hybrid wind generation application, the battery backup function is fulfilled with a bidirectional HF transformer isolated DC/DC converter. This dual-bridge series resonant converter (DBSRC) is analyzed with two ac equivalent circuit approaches for resistive load and battery load respectively, which give same results. Soft-switc.

Multi-MHz High Frequency Resonant DC-DC Power Converter

Author : Dianguo Xu
Publisher : Springer Nature
ISBN 13 : 9811574243
Total Pages : 129 pages
Book Rating : 4.8/5 (115 download)

DOWNLOAD NOW!

Book Synopsis Multi-MHz High Frequency Resonant DC-DC Power Converter by : Dianguo Xu

Download or read book Multi-MHz High Frequency Resonant DC-DC Power Converter written by Dianguo Xu and published by Springer Nature. This book was released on 2020-08-08 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book analyzes multi-MHz high frequency resonant DC-DC power converters with operating frequencies ranging from several MHz to tens of MHz in detail, aiming to support researchers and engineers with a focus on multi-MHz high frequency converters. The inverter stage, rectifier stage, matching network stage are analyzed in detail. Based on the three basic stages, typical non-isolated and isolated resonant DC-DC converters are depicted. To reduce the high driving loss under multi-MHz, resonant driving methods are introduced and improved. Also, the design and selection methods of passive and active component under multi-MHz frequency are described, especially for aircore inductor and transformer. Furthermore, multi-MHz resonant converter provides an approach for achieving flexible system.

Resonant Power Converters

Author : Marian K. Kazimierczuk
Publisher : John Wiley & Sons
ISBN 13 : 1118585860
Total Pages : 632 pages
Book Rating : 4.1/5 (185 download)

DOWNLOAD NOW!

Book Synopsis Resonant Power Converters by : Marian K. Kazimierczuk

Download or read book Resonant Power Converters written by Marian K. Kazimierczuk and published by John Wiley & Sons. This book was released on 2012-11-07 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted to resonant energy conversion in power electronics. It is a practical, systematic guide to the analysis and design of various dc-dc resonant inverters, high-frequency rectifiers, and dc-dc resonant converters that are building blocks of many of today's high-frequency energy processors. Designed to function as both a superior senior-to-graduate level textbook for electrical engineering courses and a valuable professional reference for practicing engineers, it provides students and engineers with a solid grasp of existing high-frequency technology, while acquainting them with a number of easy-to-use tools for the analysis and design of resonant power circuits. Resonant power conversion technology is now a very hot area and in the center of the renewable energy and energy harvesting technologies.

Emerging Power Converters for Renewable Energy and Electric Vehicles

Author : Md. Rabiul Islam
Publisher : CRC Press
ISBN 13 : 1000374092
Total Pages : 419 pages
Book Rating : 4.0/5 (3 download)

DOWNLOAD NOW!

Book Synopsis Emerging Power Converters for Renewable Energy and Electric Vehicles by : Md. Rabiul Islam

Download or read book Emerging Power Converters for Renewable Energy and Electric Vehicles written by Md. Rabiul Islam and published by CRC Press. This book was released on 2021-05-30 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers advancements of power electronic converters and their control techniques for grid integration of large-scale renewable energy sources and electrical vehicles. Major emphasis is on transformer-less direct grid integration, bidirectional power transfer, compensation of grid power quality issues, DC system protection and grounding, interaction in mixed AC/DC systems, AC and DC system stability, design of high-frequency high power density systems with advanced soft magnetic materials, modeling and simulation of mixed AC/DC systems, switching strategies for enhanced efficiency, and protection and reliability for sustainable grid integration. This book is an invaluable resource for professionals active in the field of renewable energy and power conversion. Md. Rabiul Islam received his PhD from the University of Technology Sydney (UTS), Australia. He was appointed as a Lecturer at Rajshahi University of Engineering & Technology (RUET) in 2005 and promoted to full-term Professor in 2017. In early 2018, he joined the School of Electrical, Computer, and Telecommunications Engineering, University of Wollongong, Australia. He is a Senior Member of IEEE. His research interests include the fields of power electronic converters, renewable energy technologies, power quality, electrical machines, electric vehicles, and smart grids. He has authored or coauthored more than 200 publications including 50 IEEE Transactions/IEEE Journal papers. He has been serving as an editor for IEEE Transactions on Energy Conversion and IEEE Power Engineering Letters, and associate editor for IEEE Access. Md. Rakibuzzaman Shah is a Senior Lecturer with the School of Engineering, Information Technology and Physical Science at Federation University Australia. He has worked and consulted with distribution network operators and transmission system operators on individual projects and has done collaborative work on a large number of projects (EPSRC project on multi-terminal HVDC, Scottish and Southern Energy multi-infeed HVDC) - primarily on the dynamic impact of integrating new technologies and power electronics into large systems. He is an active member of the IEEE and CIGRE. He has more than 70 international publications and has spoken at the leading power system conferences around the world. His research interests include future power grids (i.e., renewable energy integration, wide-area control), asynchronous grid connection through VSC-HVDC, application of data mining in power system, distribution system energy management, and low carbon energy systems. Mohd. Hasan Ali is currently an Associate Professor with the Electrical and Computer Engineering Department at the University of Memphis, USA, where he leads the Electric Power and Energy Systems (EPES) Laboratory. His research interests include advanced power systems, smart-grid and microgrid systems, renewable energy systems, and cybersecurity issues in modern power grids. Dr. Ali has more than 190 publications, including 2 books, 4 book chapters, 2 patents, 60 top ranked journal papers, 96 peer-reviewed international conference papers, and 20 national conference papers. He serves as the editor of the IEEE Transactions on Sustainable Energy and IET-Generation, Transmission and Distribution (GTD) journal. Dr. Ali is a Senior Member of the IEEE Power and Energy Society (PES). He is also the Chair of the PES of the IEEE Memphis Section.

Soft-Switched Step-Up Medium Voltage Power Converters

Author : Mehdi Abbasi
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (136 download)

DOWNLOAD NOW!

Book Synopsis Soft-Switched Step-Up Medium Voltage Power Converters by : Mehdi Abbasi

Download or read book Soft-Switched Step-Up Medium Voltage Power Converters written by Mehdi Abbasi and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With a ten-year average annual growth rate of 19 percent, wind energy has been the largest source of new electricity generation for the past decade. Typically, an offshore wind farm has a medium voltage ac (MVac) grid that collects power from individual wind turbines. Since the output voltage of a wind turbine is too low (i.e., typically 400 690 V) to be connected to the MVac grid (i.e., 20 40 kV), a heavy line-frequency transformer is used to step up the individual turbines output voltage to the MV level. To eliminate the need for bulky MVac transformers, researchers are gravitating towards the idea of replacing the MVac grid with a medium voltage dc (MVdc) grid, so that MV step-up transformers are replaced by MV step-up power electronic converters that operate at the medium frequency range with much lower size and weight. This dissertation proposes a class of modular step-up transformerless MV SiC-based power converters with soft-switching capability for wind energy conversion systems with MVdc grid. This dissertation consists of two parts: the first part focuses on the development of two novel groups of step-up isolated dc-dc MV converters that utilize various step-up resonant circuits and soft-switched high voltage gain rectifier modules. An integrated magnetic design approach is also presented to combine several magnetic components together in the modular high voltage gain rectifiers. The second part of this dissertation focuses on the development of several three-phase ac-dc step-up converters with integrated active power factor correction. In particular, a bridgeless input ac-dc rectifier is also proposed to combine with the devised step-up transformerless dc-dc converters (presented in the first part) to form the three-phase soft-switched ac-dc step-up voltage conversion unit. In each of the presented modular step-up converter configurations, variable frequency control is used to regulate the output dc voltage of each converter module. The operating principles and characteristics of each presented converter are provided in detail. The feasibility and performance of all the power converter concepts presented in this dissertation are verified through simulation results on megawatts (MW) design examples, as well as experimental results on SiC-based laboratory-scale proof-of-concept prototypes.

High-performance Single-phase Line-interfaced Power Converters

Author : Danish Shahzad
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.4/5 (64 download)

DOWNLOAD NOW!

Book Synopsis High-performance Single-phase Line-interfaced Power Converters by : Danish Shahzad

Download or read book High-performance Single-phase Line-interfaced Power Converters written by Danish Shahzad and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of single-phase line-interfaced power converters in electrical power systems is rapidly growing due to the changing nature and power quality requirements of electrical loads. Most applications require these single-phase line-interfaced power converters to be compact and efficient, and depending on application meet additional performance, cost, and reliability targets. This thesis presents innovative system architectures, circuit topologies, design methodologies, and control strategies for highly compact and efficient single-phase ac-dc and ac-ac line-interfaced power converters. First, a comprehensive design methodology for step-down isolated two-stage ac-dc converters is presented which compares various designs and operating modes and selects the optimal design based on overall volume and efficiency. Additionally, a new control strategy is presented for a compact front-end soft-switched power-factor correction (PFC) stage to ensure compliance with strict electromagnetic interference (EMI) regulations. A 1-kW universal-input to 28 V-output isolated ac-dc prototype converter is built to showcase performance benefits of proposed design and control strategies. This prototype achieves a high-power-density of 84W/in3 and maintains greater than 93% efficiency across a wide output power range. Next, the functionality of the proposed ac-dc converter is further enhanced by incorporating a new droop control strategy for parallel operation of multiple similar ac-dc converter modules. The proposed control strategy uses the input current of the secondary dc-dc stage of two-stage ac-dc converters in conjunction with variable droop resistance to achieve near-perfect parallel operation. A multi-module ac-dc conversion system is built to validate the proposed droop control strategy. The parallel modules achieve a current distribution error of less than 2% near their maximum output power. Multiple ac-ac conversion applications are also addressed in this thesis. For highly cost-sensitive applications, two compact and efficient single-stage ac-ac converters are presented which utilize a comprehensive design methodology centered around minimizing the total cost of components. Moreover, innovative control strategies are presented for both ac-ac converters to enable output voltage regulation under input voltage and output load fluctuations. Both single-stage ac-ac prototype converters, utilizing the proposed design and control strategies, are built and tested. The 600-W 480 Vrms to 264 Vrms prototypes achieve power densities exceeding 40W/in3 while maintaining conversion efficiencies of greater than 96% across majority of the output load. Finally, a much more feature-rich ac-dc-ac converter is also proposed for advanced ac-ac conversion applications, such as data center online uninterruptible power supplies (UPS). The proposed transformer-less two-stage ac-ac converter is based on a new circuit topology which can operate at high switching frequencies (up to several MHz) and utilize 50% lower dc-bus capacitance than conventional split-dc-bus topologies. A 1-k VA 120 Vrms prototype ac-dc-ac converter is built and extensively tested to showcase performance improvements. This prototype achieves high peak conversion efficiency of greater than 95% and high power density of 26.4W/in3 while utilizing long-life but relatively bulky film dc-bus capacitors.

Non-Isolated DC-DC Converters for Renewable Energy Applications

Author : Frede Blaabjerg
Publisher : CRC Press
ISBN 13 : 1000378861
Total Pages : 205 pages
Book Rating : 4.0/5 (3 download)

DOWNLOAD NOW!

Book Synopsis Non-Isolated DC-DC Converters for Renewable Energy Applications by : Frede Blaabjerg

Download or read book Non-Isolated DC-DC Converters for Renewable Energy Applications written by Frede Blaabjerg and published by CRC Press. This book was released on 2021-04-22 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaic (PV) energy generation is an excellent example of large-scale electric power generation through various parallel arrangements of small voltage-generating solar cells or modules. However, PV generation systems require power electronic converters system to satisfy the need for real-time applications or to balance the demand for power from electric. Therefore, a DC-DC power converter is a vital constituent in the intermediate conversion stage of PV power. This book presents a comprehensive review of various non-isolated DC-DC power converters. Non-isolated DC-DC converters for renewable energy system (RES) application presented in this book 1st edition through a detailed original investigation, obtained numerical/experimental results, and guided the scope to design new families of converters: DC-DC multistage power converter topologies, Multistage "X-Y converter family", Nx IMBC (Nx Interleaved Multilevel Boost Converter), Cockcroft Walton (CW) Voltage Multiplier-Based Multistage/Multilevel Power Converter (CW-VM-MPC) converter topologies, and Z-source and quasi Z-source. Above solutions are discussed to show how they can achieve the maximum voltage conversion gain ratio by adapting the passive/active component within the circuits. For assessment, we have recommended novel power converters through their functionality and designs, tested and verified by numerical software. Further, the hardware prototype implementation is carried out through a flexible digital processor. Both numerical and experimental results always shown as expected close agreement with primary theoretical hypotheses. This book offers guidelines and recommendation for future development with the DC-DC converters for RES applications based on cost-effective, and reliable solutions.

High Power Medium Voltage DC Grid-Connected Converter for Renewable Energy Generation

Author : Wu Chen
Publisher : Springer Nature
ISBN 13 : 9819749506
Total Pages : 188 pages
Book Rating : 4.8/5 (197 download)

DOWNLOAD NOW!

Book Synopsis High Power Medium Voltage DC Grid-Connected Converter for Renewable Energy Generation by : Wu Chen

Download or read book High Power Medium Voltage DC Grid-Connected Converter for Renewable Energy Generation written by Wu Chen and published by Springer Nature. This book was released on with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Single-Inductor Multiple-Output Converters

Author : Albert Ting Leung Lee
Publisher : CRC Press
ISBN 13 : 1000487741
Total Pages : 228 pages
Book Rating : 4.0/5 (4 download)

DOWNLOAD NOW!

Book Synopsis Single-Inductor Multiple-Output Converters by : Albert Ting Leung Lee

Download or read book Single-Inductor Multiple-Output Converters written by Albert Ting Leung Lee and published by CRC Press. This book was released on 2021-12-16 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides a comprehensive overview of Single-Inductor Multiple-Output Converters from both theoretical and practical perspectives. Based on the authors’ in-depth research, the volume covers not only conventional SIMO DC-DC converters but also the new generations of SIMO such as SIMO AC-DC converters, SIMO DC-AC converters (or SIMO inverters), and the latest SIMO hybrid converters. This book offers a holistic and systematic presentation of all types of SIMO converters, encompassing the derivation of the circuit topologies, the definition of key concepts, detailed discussion of theoretical underpinnings, design methodology and control schemes, as well as design considerations and techniques that enable practical implementation. Specific examples of real-world applications of SIMO converters are also provided. The volume offers a comprehensive overview and systematic classification of the traditional and modern topologies of SIMO converters in terms of system architecture, circuit analysis, operating principles, control methods, design considerations and practical implementation. Specifically, the book presents the mathematical models and design principles necessary for analyzing the behavior of each kind of SIMO converter, and building upon that, introduces and imparts new approaches and techniques when designing such converters, guiding engineering students and power engineers towards achieving low-cost, compact and energy efficient SIMO converters. offers the design considerations and optimization as well as describing the key applications of SIMO converters. The book fills a significant niche in the power electronics literature and provides a complete perspective on SIMO converters that hopefully can inspire appreciation and better understanding of the subject matter. It can be directly adopted in undergraduate or graduate coursework as well as postgraduate research programs.

High-frequency Transformer Isolated Fixed-frequency DC-DC Resonant Power Converters for Alternative Energy Applications

Author : Nagendrappa Harischandrappa
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (919 download)

DOWNLOAD NOW!

Book Synopsis High-frequency Transformer Isolated Fixed-frequency DC-DC Resonant Power Converters for Alternative Energy Applications by : Nagendrappa Harischandrappa

Download or read book High-frequency Transformer Isolated Fixed-frequency DC-DC Resonant Power Converters for Alternative Energy Applications written by Nagendrappa Harischandrappa and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The demand for power converters is on the rise due to their ability to achieve high power conversion efficiency, small size, light weight and reduced cost. DC-DC converters are used in many applications where, the output voltage needs to be regulated for wide variations in the input voltage and the load. They are also used in applications where electrical isolation is required. Power generation from renewable energy sources suffers from highly fluctuating output voltages. Electrical isolation of renewable energy sources from the grid is essential. Therefore, DC-DC converters are used as an integral part of the power electronic interface required for grid integration of renewable energy sources such as wave energy power conversion. In this dissertation as a first step, the power converters used in wave energy applications are classified and compared. Analysis, design, simulation and experimental results of fixed frequency controlled HF transformer isolated DC-DC resonant converters are presented.

Current Source DC/DC Converter Based Multi-terminal DC Wind Energy Conversion System

Author : Shixiong Fan
Publisher :
ISBN 13 :
Total Pages : 440 pages
Book Rating : 4.:/5 (966 download)

DOWNLOAD NOW!

Book Synopsis Current Source DC/DC Converter Based Multi-terminal DC Wind Energy Conversion System by : Shixiong Fan

Download or read book Current Source DC/DC Converter Based Multi-terminal DC Wind Energy Conversion System written by Shixiong Fan and published by . This book was released on 2012 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Analysis and Design of High Voltage Gain Three-Elements Resonant Soft-Switching Current-fed DC/DC Converters

Author : Venkata Ratnam Vakacharla
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (139 download)

DOWNLOAD NOW!

Book Synopsis Analysis and Design of High Voltage Gain Three-Elements Resonant Soft-Switching Current-fed DC/DC Converters by : Venkata Ratnam Vakacharla

Download or read book Analysis and Design of High Voltage Gain Three-Elements Resonant Soft-Switching Current-fed DC/DC Converters written by Venkata Ratnam Vakacharla and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transportation electrification and distributed generation are proven effective strategies to counter climate change. Modern generation and transportation aim to bring down the carbon footprint by transforming the fossil fuel-driven society with alternate energy sources and electric propulsion, respectively. However, harnessing energy from renewable sources is not straight forward but demands a suitable power electronic interface. Similarly, electric transportation propulsion system demands for specific power conversion stages. These power electronic conversion systems include dc-dc converter and dc-ac inverter. Cost, efficiency, power density, and weight are the major requirements of these converters. To obtain these merits, high-frequency soft-switching converters are selected and designed. Resonant converters with a suitable resonance have been usually explored for voltage-fed switching converters to obtain soft-switching of the semiconductor devices at high-frequency. However, owing to the high voltage gain requirements of the solar/fuel cells/batteries, this thesis explores current-fed topologies with different resonant circuits with natural voltage gain. In traditional voltage-fed resonant converters, it is observed that the converter characteristics can be fine-tuned to design the requirements by proper selection of resonant tank. In addition, the resonant tank can integrate the transformer non-idealities and circuit/device parasitic in circuit operation thereby suppressing the consequent voltage spikes across the semiconductor devices. Since voltage-fed converters is fundamentally not suitable for high voltage gain and low voltage applications, this thesis attempts to improve current-fed dc/dc converter characteristics with resonant tanks. In this thesis, a current-fed load resonant DC/DC converter topology is proposed whose characteristics are tuneable with the adopted resonant tank. Further, this thesis proposes a simple technique to ease and improve accuracy of the Fundamental Harmonic Analysis (FHA), which would have been complex otherwise due to capacitive termination of proposed converter. Initially, the characteristics of the proposed converter topology with a parallel resonance derived LCC-T resonant tank is studied to implement zero voltage switching (ZVS) and zero current switching (ZCS) of the semiconductor devices. Three-phase topology of the same has been investigated and analysed. Following the study and a need to further improve the characteristics of resonant dc/dc converter, a series resonance based LCL resonant converter, a dual of the parallel resonance tank is studied and analysed. The load resonant converters are redeemed for integration of PV/fuel cells. Further, for high power applications, suitability of load resonant converters is verified by adopting resonant tank in three-phase topology. Proof-of-concept hardware prototypes are designed and developed in the laboratory to demonstrate the performance and the merits of the proposed soft-switching resonant converter topologies as well as to prove the proposed theory and the claims.

Modular Multilevel Converters with Multi-frequency Power Transfer

Author : Yuan Li
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (141 download)

DOWNLOAD NOW!

Book Synopsis Modular Multilevel Converters with Multi-frequency Power Transfer by : Yuan Li

Download or read book Modular Multilevel Converters with Multi-frequency Power Transfer written by Yuan Li and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MMC is the dominant voltage-sourced converter technology for HVDC systems including terrestrial power transmission and offshore wind power integration. It is also a state-of-the-art solution for emerging MVDC applications such as bipolar dc distribution and grid integration of renewable energy resources. Significant research has been recently targeting the development of new MMC-based topologies that can reap the benefits of the conventional dc-ac MMC in dc grids and hybrid ac/dc power systems. Notable examples include dc-dc converters, multi-port converters, line power flow controllers and power tapping stations. This thesis introduces the concept of multi-frequency power transfer in MMCs where the magnetics windings are multi-tasked to carry currents with multiple frequency components, namely dc and fundamental frequency. Core dc flux cancellation is imposed by appropriate orientation of the individual windings. This novel power transfer mechanism can eliminate redundant energy conversion through partial-power-processing while offering increased flexibility in converter port power flows. Based on the multi-frequency power transfer concept, new MMC-based topologies are proposed that are well suited for MVDC and HVDC grids and hybrid ac/dc systems. Firstly, a new class of single-stage modular multilevel dc-dc converter, termed the M2DC-CT, is proposed for applications requiring either high or low dc stepping ratios. By placing center-tapped transformer windings in series with the arms in each phase leg, the advantages of minimized ac arm currents and absence of dc voltage stress between windings are simultaneously obtained unlike in prior art. Modeling and analysis gives insight into the M2DC-CT multi-frequency power transfer characteristics and suitable converter controls are developed. Converter operation is validated through simulation and experiment. %The M2DC-CT is further extended into a three-port converter by addition of a grid side transformer winding. Secondly, a dual MMC structure is presented that achieves multi-frequency power transfer by tying together the three mid-points of the converter-side center-tapped transformer windings to form an additional dc port. This creates a bipolar MMC with the ability to balance the dc pole power flows in bipolar dc grids. The employed center-tapped transformer has a Volt-Ampere rating that is the same as a conventional grid interfacing transformer. Dynamic controls formulated in the $\alpha\beta$-frame provide tight regulation of the port power flows while ensuring balanced capacitor voltages. The independent pole balancing capability is confirmed through simulation of detailed MVDC-level and HVDC-level PSCAD models and rigorous experimental testing on a scaled-down laboratory prototype. Thirdly, the aforementioned multi-frequency dual MMC structure is proposed for use as a three-port MMC. It allows simultaneous dc-dc and dc-ac conversions between an ac grid and two dc systems, which is distinctly different from the earlier bipolar dc grid application. The $\alpha\beta$ controls developed earlier are easily extended for the three-port application by assigning appropriate reference signals. Steady-state and dynamic operation of the three-port dual MMC topology is validated by simulation with a HVDC-level PSCAD model and extensive experimental tests. Lastly, a detailed comparative assessment of three-port MMCs for high-power applications is conducted. The proposed three-port dual MMC structure and three-port version of the M2DC-CT are compared against two other existing three-port MMCs, on the basis of efficiency, semiconductor effort, internal energy storage and magnetics. Both MVDC and HVDC case studies are examined including several different power flow cases, with provisions for fault blocking. The results indicate the use of multi-frequency power transfer can enable significant reductions in converter operating losses and cost relative to prior art, depending on the application.

Three-phase High-frequency Transformer Isolated Soft-switching DC-DC Resonant Converters

Author : Mohamed S. M. Almardy
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (858 download)

DOWNLOAD NOW!

Book Synopsis Three-phase High-frequency Transformer Isolated Soft-switching DC-DC Resonant Converters by : Mohamed S. M. Almardy

Download or read book Three-phase High-frequency Transformer Isolated Soft-switching DC-DC Resonant Converters written by Mohamed S. M. Almardy and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an increasing demand for power converters with small size, light weight, high conversion efficiency and higher power density. Also, in many applications, there is a need for dc-to-dc converters to accept dc input voltage and provide regulated and/or isolated dc output voltage at a desired voltage level including telecommunications equipment, process control systems, and in industry applications. This thesis presents the analysis, design, simulation and experimental results of three-phase high-frequency transformer isolated resonant converters. The first converter presented is a three-phase LCC-type dc-dc resonant converter with capacitor output filter including the effect of the magnetizing inductance of the three-phase HF transformer. The equivalent ac load resistance is derived and the converter is analyzed by using approximation analysis approach. Base on this analysis, design curves have been obtained and a design example is given. Intusoft simulation results for the designed converter are given for various input voltage and for different load conditions. The experimental verification of the designed converter performance was established by building a 300 W rated power converter and the experimental results have been given. It is shown that the converter works in zero-voltage switching (ZVS) at various input voltage and different load conditions. A three-phase (LC)(L)-type dc-dc series-resonant converter with capacitive output filter has been proposed. Operation of the converter has been presented using the operating waveforms and equivalent circuit diagrams during different intervals. An approximate analysis approach is used to analyze the converter operation, and design procedure is presented with a design example. Intusoft simulation results for the designed converter are given for input voltage and load variations. Experimental results obtained in a 300 W converter are presented. Major advantages of this converter are the leakage and magnetizing inductances of the high-frequency transformer are used as part of resonant circuit and the output rectifier voltage is clamped to the output voltage. The converter operates in soft-switching for the inverter switches for the wide variations in supply voltage and load and it requires narrow switching frequency variation (compared to LCC-type) to regulate the output voltage. A three-phase high-frequency transformer isolated interleaved (LC)(L)-type dc-dc series-resonant converter with capacitive output filter using fixed frequency control is proposed. The converter operation for different modes is presented using the operating waveforms and equivalent circuit diagrams during different intervals. This converter is modeled and then analyzed using the approximate complex ac circuit analysis approach. Based on the analysis, design curves were obtained and the design procedure is presented with a design example. The designed converter is simulated using PSIM software to predict the performance of the converter for variations in supply voltage and load conditions. The converter operates in ZVS for the inverter switches with minimum input voltage and loses ZVS for two switches in each bridge for higher input voltages.

Fault-tolerant Partial-resonant High-frequency AC-link Converters and Their Applications

Author : Hamidreza Keyhani
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (92 download)

DOWNLOAD NOW!

Book Synopsis Fault-tolerant Partial-resonant High-frequency AC-link Converters and Their Applications by : Hamidreza Keyhani

Download or read book Fault-tolerant Partial-resonant High-frequency AC-link Converters and Their Applications written by Hamidreza Keyhani and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, the demand for high-power-density converters with high efficiency and enhanced reliability has increased considerably. To address this demand, this dissertation introduces several low, medium, and high power converter topologies with high-frequency ac links and soft-switching operation, both with and without galvanic isolation. These converters can be in ac-ac, dc-ac, ac-dc, or dc-dc configurations to transfer power from the utility, energy storage systems, or renewable/alternative energy sources (e.g., photovoltaics, wind, and fuel cells) to stand-alone loads or the utility. The advantages of these topologies include soft switching at turn-on and turn-off of all the semiconductor devices, exclusion of short-life electrolytic capacitors in the link, step-up/down capability, and the use of a smallsized high-frequency transformer for galvanic isolation. The proposed converters are also able to generate output waveforms with arbitrary amplitude and frequency as well as achieving a high input power factor in the ac-ac and ac-dc configurations. Moreover, some of the introduced topologies have fault-tolerance capability, which may allow the converter to run even with one or more faulty switches. In this case, a partial failure will not result in the converter shutdown, and thus system availability is improved. The high-frequency ac link of the introduced converters is composed of an ac inductor and small ac capacitor. The link inductor is responsible for transferring power, while the link capacitor realizes soft-switching operation. As the link components have low reactive ratings, the converters exhibit fast dynamic responses. The inductor can be replaced by an air-gapped high-frequency transformer to achieve galvanic isolation without the need for any snubber circuits. Due to operation at a high frequency, the link transformer is substantially smaller in size and lower in weight compared to conventional line-frequency isolation transformers. In this work, the proposed power topologies are explained in detail, and their comprehensive analyses are given to reveal their functioning behavior in various working conditions. Simulation and experimental results at different operating points are also presented to verify the effectiveness of the introduced power converters. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/152456

Single Stage Soft-switched High-frequency Transformer Isolated AC-to-DC Bridge Converter and Extension to Multiphase Converter

Author : M. M. Azizur Rahman
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (119 download)

DOWNLOAD NOW!

Book Synopsis Single Stage Soft-switched High-frequency Transformer Isolated AC-to-DC Bridge Converter and Extension to Multiphase Converter by : M. M. Azizur Rahman

Download or read book Single Stage Soft-switched High-frequency Transformer Isolated AC-to-DC Bridge Converter and Extension to Multiphase Converter written by M. M. Azizur Rahman and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the operation, analysis, simulation and experimental results of a single-phase single-stage soft-switched high frequency (HF) transformer isolated ac-to-dc bridge converter with low total harmonic distortion (THD) and its extension to ac-to-dc multiphase converter. A single-phase single-stage soft-switched ac-to-dc bridge converter cell has been proposed based on a new gating scheme. Due to the discontinuous current mode (DCM) operation of the boost inductor, natural power factor correction and low THD are ensured. The single-stage ac-to-dc multiphase converter is realized based on this bridge converter cell to reduce HF harmonic components in the line current. The steady-state operation of the single-stage bridge converter is explained for all operating modes. Intervals of operation in these modes are identified and analyzed. The steady-state solutions are presented. Based on these solutions, design curves are obtained. Design example of a 1.7 kW converter is presented to illustrate the design procedure. Operational characteristics are obtained for different line and load conditions. PSPICE simulation results for the designed converter are presented. An experimental prototype is built to verify the operation and performance of the converter. All four switches in the fixed frequency bridge converter undergo soft switching (common switch requires an auxiliary circuit) for a wide line and load range. A single-stage HF transformer isolated ac-to-dc multiphase converter is proposed. The analyses of the single-stage bridge converter cell are extended to the multiphase converter. It is shown that N = 3 is near the optimum number of cells to reduce the input current HF harmonic components. A design example of a 166 to 260 V (rms) input, 420 V output, 5 kW converter switching at 50 kHz is presented. PSPICE simulation results are obtained for the designed converter to study its performance for varying load and line conditions. A 3-cell 1.5 kW experimental prototype is built and experimental results are obtained. All the results show that HF harmonics in the line current are reduced and output voltage ripple frequency is increased. Each cell handles equal power and all bridge-switches are soft switched. As a result, uniform thermal distribution is obtained. Small-signal analysis of the single-stage ac-to-dc bridge converter cell is presented for all operating modes using state-space averaging technique. Based on this analysis, small signal transfer functions are obtained. Frequency response of the transfer functions are plotted using MATLAB program and verified by PSPICE simulation results. A closed loop control system is designed and frequency response of the overall loop gain is presented. Large-signal transient behavior of the converter cell is studied with open loop using PSPICE simulation program for step change in line and load conditions. The simulation results show that the closed loop system is required to improve the converter performance during step increase in line voltage.