A Triangular Modular Multilevel Dc Dc Converter With Multiple Input Multiple Output Power Flow Capability

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A Triangular Modular Multilevel DC-DC Converter with Multiple-input Multiple-output Power Flow Capability

Author : Kia Filsoof
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (133 download)

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Book Synopsis A Triangular Modular Multilevel DC-DC Converter with Multiple-input Multiple-output Power Flow Capability by : Kia Filsoof

Download or read book A Triangular Modular Multilevel DC-DC Converter with Multiple-input Multiple-output Power Flow Capability written by Kia Filsoof and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been recent interest in expansion of direct-current (dc) networks, motivated mainly by proliferation of renewable energy sources, electrical energy storage, and electronic loads which operate with dc power. One of the key challenges hindering the adoption of dc networks is the lack of high performance dc-dc converter topologies to accommodate energy exchange, at high power levels, between dc buses of different voltage levels. Conventional dc-dc power converters such as the boost or the flyback face a fundamental limitation in operating at high power levels and/or voltage conversion ratios. As these topologies utilize a single semiconductor switch, their maximum attainable power and voltage rating is dependent on the highest power rated semiconductors available. Moreover, regardless of the operating power, these topologies suffer from high losses and ringing when operated at high conversion ratios. In recognizing the shortcomings of conventional topologies for employment in high power and/or conversion ratio applications, a new topology is proposed that provides an efficient and cost-effective solution. The proposed modular topology is constructed from identical converter cells which may be connected in parallel and series to share the overall power stress. As a result, the dependency of the topology's power and conversion ratio on existing semiconductor technology is insignificant. Moreover, the topology is capable of supporting bidirectional power flow exchange between multiple sources and loads which makes it suitable for a wide range of power conversion applications. The proposed topology can achieve a conversion ratio of six with half of its switches operating at a duty cycle value 25% lower and the other half of its switches operating at a duty cycle value 40% lower than that of the conventional boost converter while requiring only 15% higher switch volt-ampere rating. The proposed converter's operating mechanism is described, and its analytical steady-state and dynamic models are derived. In investigating the topology's dynamic model, a modular control algorithm is devised for closed-loop operation of the topology. The ability of the topology to operate as a multiple-input multiple-output converter is also investigated through similar analytical and control studies. Simulation and experimental studies are carried out to evaluate the converter's performance under both steady-state and dynamic operation.

Modular Multilevel Converters with Multi-frequency Power Transfer

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

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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.

Multi-terminal High-voltage Converter

Author : Bo Zhang
Publisher : John Wiley & Sons
ISBN 13 : 1119188350
Total Pages : 224 pages
Book Rating : 4.1/5 (191 download)

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Book Synopsis Multi-terminal High-voltage Converter by : Bo Zhang

Download or read book Multi-terminal High-voltage Converter written by Bo Zhang and published by John Wiley & Sons. This book was released on 2018-10-19 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: An all-in-one guide to high-voltage, multi-terminal converters, this book brings together the state of the art and cutting-edge techniques in the various stages of designing and constructing a high-voltage converter. The book includes 9 chapters, and can be classified into three aspects. First, all existing high-voltage converters are introduced, including the conventional two-level converter, and the multi-level converters, such as the modular multi-level converter (MMC). Second, different kinds of multi-terminal high-voltage converters are presented in detail, including the topology, operation principle, control scheme and simulation verification. Third, some common issues of the proposed multi-terminal high-voltage converters are discussed, and different industrial applications of the proposed multi-terminal high-voltage converters are provided. Systematically proposes, for the first time, the design methodology for high-voltage converters in use of MTDC grids; also applicable to constructing novel power electronics converters, and driving the development of HVDC, which is one of the most important technology areas Presents the latest research on multi-terminal high-voltage converters and its application in MTDC transmission systems and other industrially important applications Offers an overview of existing technology and future trends of the high-voltage converter, with extensive discussion and analysis of different types of high-voltage converters and relevant control techniques (including DC-AC, AC-DC, DC-DC, and AC-AC converters) Provides readers with sufficient context to delve into the more specialized topics covered in the book Featuring a series of novel multi-terminal high-voltage converters proposed and patented by the authors, Multi-terminal High Voltage Converters is written for researchers, engineers, and advanced students specializing in power electronics, power system engineering and electrical engineering.

A New Class of Modular Multilevel DC/DC Converters for HVDC Systems

Author : Gregory Joseph Kish
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (133 download)

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Book Synopsis A New Class of Modular Multilevel DC/DC Converters for HVDC Systems by : Gregory Joseph Kish

Download or read book A New Class of Modular Multilevel DC/DC Converters for HVDC Systems written by Gregory Joseph Kish and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis develops a new class of modular multilevel dc/dc converters, termed the DC-MMC, that can be deployed to interconnect HVDC networks of different or similar voltage levels. Advanced operating features include buck/boost functionality and bidirectional dc fault blocking analogous to a dc circuit breaker. A key advantage of the DC-MMC is that it eliminates the full-rated intermediate ac conversion stage traditionally employed by modular multilevel converter (MMC) based two-stage dc/dc converters, i.e. dc/ac-ac/dc conversion. This is enabled by a new single-stage bidirectional dc/dc conversion process that requires only a fraction of the dc power throughput to be internally circulated as ac power. In comparison to state-of-the-art MMC based two-stage dc/dc conversion, the DC-MMC enables up to a 50\% reduction in total semiconductor expenditure and total capacitive energy storage requirements, translating to commensurate savings in converter capital cost and operating losses. The DC-MMC principle of operation is validated via simulation of a comprehensive switched model in PLECS. To gain deeper insight into DC-MMC dynamics and internal power transfer mechanisms, this thesis exploits the use of dynamic phasors to accommodate the multiple frequency components that exist at steady-state. Large-signal and small-signal time-invariant dynamic phasor models are derived. The large-signal phasor model enables: 1) solving for the full steady-state solution of the DC-MMC under arbitrary loading, and 2) evaluation of DC-MMC open-loop stability via eigenvalue analysis. Based on the small-signal phasor model, a dynamic controller suitable for dc network applications is proposed that regulates output power while ensuring individual capacitor voltages remain balanced. The developed analytical models and dynamic controls are validated by simulation. Bidirectional dc fault blocking capability is also confirmed by simulation. Experimental results for a 4 kW prototype validate the single-stage dc/dc conversion process for both step-down and step-up operating modes.

Modular Multilevel Converters

Author : Sixing Du
Publisher : John Wiley & Sons
ISBN 13 : 1119366305
Total Pages : 360 pages
Book Rating : 4.1/5 (193 download)

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Book Synopsis Modular Multilevel Converters by : Sixing Du

Download or read book Modular Multilevel Converters written by Sixing Du and published by John Wiley & Sons. This book was released on 2018-01-11 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: An invaluable academic reference for the area of high-power converters, covering all the latest developments in the field High-power multilevel converters are well known in industry and academia as one of the preferred choices for efficient power conversion. Over the past decade, several power converters have been developed and commercialized in the form of standard and customized products that power a wide range of industrial applications. Currently, the modular multilevel converter is a fast-growing technology and has received wide acceptance from both industry and academia. Providing adequate technical background for graduate- and undergraduate-level teaching, this book includes a comprehensive analysis of the conventional and advanced modular multilevel converters employed in motor drives, HVDC systems, and power quality improvement. Modular Multilevel Converters: Analysis, Control, and Applications provides an overview of high-power converters, reference frame theory, classical control methods, pulse width modulation schemes, advanced model predictive control methods, modeling of ac drives, advanced drive control schemes, modeling and control of HVDC systems, active and reactive power control, power quality problems, reactive power, harmonics and unbalance compensation, modeling and control of static synchronous compensators (STATCOM) and unified power quality compensators. Furthermore, this book: Explores technical challenges, modeling, and control of various modular multilevel converters in a wide range of applications such as transformer and transformerless motor drives, high voltage direct current transmission systems, and power quality improvement Reflects the latest developments in high-power converters in medium-voltage motor drive systems Offers design guidance with tables, charts graphs, and MATLAB simulations Modular Multilevel Converters: Analysis, Control, and Applications is a valuable reference book for academic researchers, practicing engineers, and other professionals in the field of high power converters. It also serves well as a textbook for graduate-level students.

Advanced Multi-Quadrant Operation DC/DC Converters

Author : Fang Lin Luo
Publisher : CRC Press
ISBN 13 : 9780849372391
Total Pages : 224 pages
Book Rating : 4.3/5 (723 download)

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Book Synopsis Advanced Multi-Quadrant Operation DC/DC Converters by : Fang Lin Luo

Download or read book Advanced Multi-Quadrant Operation DC/DC Converters written by Fang Lin Luo and published by CRC Press. This book was released on 2005-10-31 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are several families of DC/DC converters comprising hundreds of different topologies. Sorting through the various properties and characteristics is obviously a daunting task. Culled from the pages of the groundbreaking Advanced DC/DC Converters, this book provides a focused, concise overview of more than 50 topologies of multi-quadrant converters. All aspects of these topologies are illustrated through designs developed by the authors through the years. The book begins with multiple-quadrant converters followed by switched component (SC and SI) converters, multiple-lift push-pull switched-capacitor converters, and finally, multiple-quadrant soft-switching converters.

Advanced Multiphasing Switched-Capacitor DC-DC Converters

Author : Nicolas Butzen
Publisher : Springer Nature
ISBN 13 : 3030387356
Total Pages : 160 pages
Book Rating : 4.0/5 (33 download)

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Book Synopsis Advanced Multiphasing Switched-Capacitor DC-DC Converters by : Nicolas Butzen

Download or read book Advanced Multiphasing Switched-Capacitor DC-DC Converters written by Nicolas Butzen and published by Springer Nature. This book was released on 2020-07-03 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a detailed analysis of switched-capacitor DC-DC converters that are entirely integrated on a single chip and establishes that these converters are mainly limited by the large parasitic coupling, the low capacitor energy density, and the fact that switched-capacitor converter topologies only have a fixed voltage conversion ratio. The authors introduce the concept of Advanced Multiphasing as a way to circumvent these limitations by having multiple out-of-phase parallel converter cores interact with each other to minimize capacitor charging losses, leading to several techniques that demonstrate record efficiency and power-density, and even a fundamentally new type of switched-capacitor topology that has a continuously-scalable conversion ratio. Provides single-source reference to the recently-developed Advanced Multiphasing concept; Enables greatly improved performance and capabilities in fully integrated switched-capacitor converters; Enables readers to design DC-DC converters, where multiple converter cores are put in parallel and actively interact with each other over several phases to improve their capabilities.

Design, Analysis, and Control of the Modular Multilevel DC/DC Converter for Medium- and High-voltage DC Grids

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

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Book Synopsis Design, Analysis, and Control of the Modular Multilevel DC/DC Converter for Medium- and High-voltage DC Grids by : Ramin Razani

Download or read book Design, Analysis, and Control of the Modular Multilevel DC/DC Converter for Medium- and High-voltage DC Grids written by Ramin Razani and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, renewable energy sources have gained escalating importance due to environmental and economic reasons. However, these energy sources are primarily located in remote areas and distant from load centers. High-voltage dc (HVDC) and medium-voltage dc (MVDC) systems have been proposed in the last decades for efficient and reliable integration of renewable energy resources. To date, a noticeable number of these dc systems are established around the world. Recently, researchers have proposed the concept of "DC grids," which can be realized by connecting the existing point-to-point dc systems. This structure can improve the efficiency and stability of the power system. However, one of the most concerning challenges related to this concept is the interconnection of already built dc systems. Because existing dc systems are built through time, they possibly have different voltage levels and grounding systems. To address this challenge, the dc/dc modular multilevel converter (MMC) is proposed in the literature as one of the most promising solutions. This converter offers the advantages of modularity, scalability, and high efficiency. Few studies have been conducted on the modeling and control of the dc/dc MMC. The literature falls short in several aspects, such as improved design, analysis of operation limits, fault-tolerant operation, converter analysis under uncertainty, and development of advanced controllers and efficient fault-blocking capability. This research aims to 1) develop an augmented design approach that considers both control and hardware aspects of the converter, 2) investigate the operation limit of the hybrid dc/dc MMC caused by the capacitors voltages unbalance, 3) develop a tailored fault-tolerant operation strategy without additional submodules (SMs), 4) analyze the unsymmetrical operation of the dc/dc MMC caused by parametric uncertainty, 5) develop an advanced controller based on the model predictive control for the dc/dc MMC, and 6) realize an efficient fault-blocking capability by proper selection of SMs. The first study in this thesis facilitates the dc/dc MMC design with a smaller number of SMs and higher efficiency. Unlike the previous literature, the analytical results of the second study show that the capacitors voltages balance in the hybrid dc/dc MMC limits the operation range of the converter. In the third study, first, the unique features of the dc/dc MMC are investigated. These features make the fault-tolerant operation possible without the need for additional SMs. Then, utilizing these features, a tailored fault-tolerant operation strategy is developed to cope with several SMs failures. When the parametric uncertainty comes into action, it can force the converter to work in unsymmetrical conditions. The fourth study develops steady-state models representing the behavior of the converter in unsymmetrical conditions, and then the maximum tolerable variation of parameters is found in different practical cases. An advanced controller based on the model predictive control is developed in the fifth study to improve the steady-state and transient performances of the dc/dc MMC. Finally, an efficient fault-blocking capability is realized by adequately selecting the number and type of SMs. Detailed time-domain simulations under the MATLAB/Simulink environment validate the analytical results. This research contributed to the fundamental understanding of the dc/dc MMC operation and significantly improved the converter efficiency, reliability, and steady-state and dynamic performances.

Analysis and Loss Estimation of Different Multilevel DC-DC Converter Modules and Different Proposed Multilevel DC-DC Converter Systems

Download Analysis and Loss Estimation of Different Multilevel DC-DC Converter Modules and Different Proposed Multilevel DC-DC Converter Systems PDF Online Free

Author : Sandeep Patil
Publisher :
ISBN 13 :
Total Pages : 94 pages
Book Rating : 4.:/5 (894 download)

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Book Synopsis Analysis and Loss Estimation of Different Multilevel DC-DC Converter Modules and Different Proposed Multilevel DC-DC Converter Systems by : Sandeep Patil

Download or read book Analysis and Loss Estimation of Different Multilevel DC-DC Converter Modules and Different Proposed Multilevel DC-DC Converter Systems written by Sandeep Patil and published by . This book was released on 2014 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multilevel DC-DC converter converts a DC source from one voltage level to another level. DC-DC converters are important in portable devices like cell phones, laptops, etc, as well as in applications such as electric vehicles, which have subcircuits operating at voltages diff erent from the supply voltage. In this thesis, two new multilevel DC-DC converter system modules: one-to-many topology and cascaded topology are presented. Comparisons are made for the proposed multilevel DC-DC converter systems along with the existing multilevel DC-DC converter system. The comparisons are made in the terms of range of the output voltage, maximum output voltage, number of steps of output voltages, number of switches operated for any given output voltage, and the ripples in the output voltage. Among all the proposed converter system topologies, cascaded topology with even number of modules turned out to be more efficient in terms of maximum output voltage and number of steps of output voltages. Two new di fferent multilevel DC-DC converter modules are presented in this thesis. However only one of them facilitates the implementation of cascaded topology of DC-DC converters and decrease the transition currents, while other just decrease the transition currents. Comparisons are based on diff erent losses during the circuit operation, ripple voltages, and efficiency. One of the proposed converter modules limits the transient currents signfi cantly over existing converters during the output voltage transition in multilevel DC-DC converter topologies for a given transition time. Though the efficiencies of the proposed modules are slightly less (

Modular DC/DC Converter Structure with Multiple Power Flow Paths for Smart Transformer Applications

Author : Giampaolo Buticchi
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (971 download)

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Book Synopsis Modular DC/DC Converter Structure with Multiple Power Flow Paths for Smart Transformer Applications by : Giampaolo Buticchi

Download or read book Modular DC/DC Converter Structure with Multiple Power Flow Paths for Smart Transformer Applications written by Giampaolo Buticchi and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

A Ćuk-based Modular DC-DC Converter for Medium-voltage Direct-current (MVDC) Grid Applications

Author : Abdulgafor Mohammed Alfares
Publisher :
ISBN 13 :
Total Pages : 66 pages
Book Rating : 4.:/5 (123 download)

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Book Synopsis A Ćuk-based Modular DC-DC Converter for Medium-voltage Direct-current (MVDC) Grid Applications by : Abdulgafor Mohammed Alfares

Download or read book A Ćuk-based Modular DC-DC Converter for Medium-voltage Direct-current (MVDC) Grid Applications written by Abdulgafor Mohammed Alfares and published by . This book was released on 2020 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A reliable modular DC-DC converter that is well-suited to the MVDC grid applications is presented in this dissertation. This converter benefits from zero current turn-off and soft turn-on switching. Each power module is designed and controlled such that it employs two small film capacitors for transferring the power from the input to the output. This feature eliminates the need for electrolytic capacitors that have high failure rates. Furthermore, each power module is configured as an isolated converter, using an integrated high frequency transformer. Each power module in the proposed modular converter sees only one semiconductor on the conduction path to transfer energy from the input to the link capacitors or from the link capacitors to the output, which results in relatively low conduction losses. Another advantage of the proposed converter is the possibility of having bidirectional flow of power. The zero current turn-off feature in the proposed converter allows using any type of active switches, even Silicon Controlled Rectifiers (SCRs), which are naturally commuted switches. SCRs have numerous advantages over the other power switches, including higher voltage ratings and current ratings, lower power losses, lower cost, and higher reliability, which are all of particular importance in the MVDC grid application. The main limitation of SCRs is that they have natural commutation and cannot be turned off with gate signals. The approach employed in this dissertation enables the use of SCRs in the proposed modular DC-DC converters. The input and output terminals of the power modules can be connected in series or in parallel to form modular converters that facilitate sharing voltage or current in high power applications. In this dissertation, an input-parallel output-series (IPOS) modular configuration is considered to increase the voltage blocking capability at the output and handle high currents at the input of the converter. The dissertation studies the principles of the operation of this converter and presents its design procedure. Also, a modified topology for reducing the number of inputs switches is proposed. Multi-port configurations that allow having several independent input sources in this modular DC-DC converter are presented in this dissertation. In addition, a brief comparison between the proposed topology and a dual active bridge (DAB)-based modular converter, which is the most common DC-DC converter topology used in MVDC grid, is carried out. In addition, the performance of the proposed modular converter is evaluated through simulations and experiments"--Author's abstract.

Design of Modular Multilevel Converter-based Solid State Transformers

Author : Ali Shojaei
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (98 download)

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Book Synopsis Design of Modular Multilevel Converter-based Solid State Transformers by : Ali Shojaei

Download or read book Design of Modular Multilevel Converter-based Solid State Transformers written by Ali Shojaei and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "A Solid State Transformer (SST) performs the tasks of a conventional transformer by means of power electronic converters and high-frequency transformers. In addition to voltage level transformation, some SST topologies are able to provide ancillary services to the AC grid.In a three-stage SST, the first-stage is an AC/DC converter. In most designs, this stage employs a multilevel converter topology rather than a two-level converter. The reason for this is that a multilevel converter provides such advantages as capability to interface with a medium voltage AC grid. Among all multilevel converter topologies, a new generation of multilevel converters called Modular Multilevel Converter (MMC) has been considered to be a promising topology for medium/high voltage converters in back to back and High-Voltage DC (HVDC) applications.This thesis first studies the design, modulation, and control of an MMC. In this context, a modulation and control strategy is proposed which decreases the level of harmonics in the output voltage and current of the converter. Further, the proposed strategy pushes the harmonics towards higher frequencies and, hence, allows the converter to be switched at lower frequencies. Next, this thesis proposes a number of three-stage SST configurations employing an MMC in their first stage. An advantage of the proposed SST configurations is that they are readily scalable to higher voltage levels and power ratings; this enables the application of an SST in higher levels of electrical grids. Further, the proposed SSTs feature a high-voltage DC terminal in addition to the commonly provided terminals to enable connection of the SST to a DC distribution grid." --

Modeling, Design, Control and Validation of a Multiple-input DC-DC Converter Topology for Effective Renewable Energy Management

Author : Hassan AboReada
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (134 download)

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Book Synopsis Modeling, Design, Control and Validation of a Multiple-input DC-DC Converter Topology for Effective Renewable Energy Management by : Hassan AboReada

Download or read book Modeling, Design, Control and Validation of a Multiple-input DC-DC Converter Topology for Effective Renewable Energy Management written by Hassan AboReada and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple-input power converters are receiving significant research attention as they offer several advantages over conventional converters, specifically their ability to interface multiple energy sources of various kinds. Additionally, they have promising features such as less components, higher power density and centralized control. A novel multiple-input single-output DC-DC converter topology is proposed for effective energy management. The topology is designed depending on the conventional structure of boost and buck converters and benefits greatly from this combination. Effective energy management strategy is used and a simple control system is introduced by utilizing voltage and current control. The converter is simulated and implemented in hardware testing as a 300W system to confirm the performance and validation of the topology and it is capable of supplying constant output power through different input sources with any voltage variation. The results show a high performance and all of the operating modes have been investigated.

DC-DC Converter Designs for Medium and High Voltage Direct Current Systems

Author : Islam Azmy Gowaid
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (141 download)

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Book Synopsis DC-DC Converter Designs for Medium and High Voltage Direct Current Systems by : Islam Azmy Gowaid

Download or read book DC-DC Converter Designs for Medium and High Voltage Direct Current Systems written by Islam Azmy Gowaid and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: DC fault protection is one challenge impeding the development of multi-terminal dc grids. The absence of manufacturing and operational standards has led to many point-to-point HVDC links built at different voltage levels, which creates another challenge. Therefore, the issues of voltage matching and dc fault isolation in high voltage dc systems are undergoing extensive research and are the focus of this thesis. The modular multilevel design of dual active bridge (DAB) converters is analysed in light of state-of-the-art research in the field. The multilevel DAB structure is meant to serve medium and high voltage applications. The modular design facilitates scalability in terms of manufacturing and installation, and permits the generation of an output voltage with controllable dv/dt. The modular design is realized by connecting an auxiliary soft voltage clamping circuit across each semiconductor switch (for instance insulated gate bipolar transistor - IGBT) of the series switch arrays in the conventional two-level DAB design. With auxiliary active circuits, series connected IGBTs effectively become series connection of half-bridge submodules (cells) in each arm, resembling the modular multilevel converter (MMC) structure. For each half-bridge cell, capacitance for quasi-square wave (quasi two- level) operation is significantly smaller than typical capacitance used in MMCs. Also, no bulky arm inductors are needed. Consequently, the footprint, volume, weight and cost of cells are lower. Four switching sequences are proposed and analysed in terms of switching losses and operation aspects. A design method to size converter components is proposed and validated. Soft-switching characteristics of the analysed DAB are found comparable to the case of a two-level DAB at the same ratings and conditions. A family of designs derived from the proposed DAB design are studied in depth. Depending on the individual structure, they may offer further advantages in term of installed semiconductor power, energy storage, conduction losses, or footprint. A non-isolated dc-dc converter topology which offers more compact and efficient station design with respect to isolated DAB - yet without galvanic isolation - is studied for quasi two-level (trapezoidal) operation and compared to the isolated versions. In all the proposed isolated designs, active control of the dc-dc converter facilitates dc voltage regulation and near instant isolation of pole-to-pole and pole-to-ground dc faults within its protection zone. The same can be achieved for the considered non-isolated dc-dc converter topology with additional installed semiconductors. Simulation and experimental results are presented to substantiate the proposed concepts.

Analysis, Modeling, and Control of Highly-efficient Hybrid Dc-dc Conversion Systems

Author : Ruichen Zhao
Publisher :
ISBN 13 :
Total Pages : 336 pages
Book Rating : 4.:/5 (826 download)

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Book Synopsis Analysis, Modeling, and Control of Highly-efficient Hybrid Dc-dc Conversion Systems by : Ruichen Zhao

Download or read book Analysis, Modeling, and Control of Highly-efficient Hybrid Dc-dc Conversion Systems written by Ruichen Zhao and published by . This book was released on 2012 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation studies hybrid dc-dc power conversion systems based on multiple-input converters (MICs), or more generally, multiport converters. MICs allow for the integration of multiple distributed generation sources and loads. Thanks to the modular design, an MIC yields a scalable system with independent control in all sources. Additional characteristics of MICs include the improved reliability and reduced cost. This dissertation mainly studies three issues of MICs: efficiency improvement, modeling, and control. First, this work develops a cost-effective design of a highly-efficient non-isolated MIC without additional components. Time-multiplexing (TM) MICs, which are driven by a time-multiplexing switching control scheme, contain forward-conducting-bidirectional-blocking (FCBB) switches. TM-MICs are considered to be subject to low efficiency because of high power loss introduced by FCBB switches. In order to reduce the power loss in FCBB switches, this work adopts a modified realization of the FCBB switch and proposes a novel switching control strategy. The design and experimental verifications are motivated through a multiple-input (MI) SEPIC converter. Through the design modifications, the switching transients are improved (comparing to the switching transients in a conventional MI-SEPIC) and the power loss is significantly reduced. Moreover, this design maintains a low parts-count because of the absence of additional components. Experimental results show that for output power ranging from 1 W to 220 W, the modified MIC presents high efficiency (96 % optimally). The design can be readily extended to a general n-input SEPIC. The same modifications can be applied to an MI-Ćuk converter. Second, this dissertation examines the modeling of TM-MICs. In the dynamic equations of a TM-MIC, a state variable from one input leg is possible to be affected by state variables and switching functions associated with other input legs. In this way, inputs are coupled both topologically and in terms of control actions through switching functions. Coupling among the state variable and the time-multiplexing switching functions complicate TM-MICs' behavior. Consequently, substantial modeling errors may occur when a classical averaging approach is used to model an MIC even with moderately high switching frequencies or small ripples. The errors may increase with incremental number of input legs. In addition to demonstrating the special features on MIC modeling, this dissertation uses the generalized averaging approach to generate a more accurate model, which is also used to derive a small-signal model. The proposed model is an important tool that yields better results when analyzing power budgeting, performing large-signal simulations, and designing controllers for TM-MICs via a more precise representation than classical averaging methods. Analyses are supported by simulations and experimental results. Third, this dissertation studies application of a decentralized controller on an MI-SEPIC. For an MIC, a multiple-input-multiple-output (MIMO) state-space representation can be derived by an averaging method. Based on the averaged MIMO model, an MIMO small-signal model can be generated. Both conventional method and modern multivariable frequency analysis are applied to the small-signal model of an MI-SEPIC to evaluate open-loop and closed-loop characteristics. In addition to verifying the nominal stability and nominal performance, this work evaluates robust stability and robust performance with the structured singular value. The robust performance test shows that a compromised performance may be expected under the decentralized control. Simulations and experimental results verify the theoretical analysis on stability and demonstrate that the decentralized PI controller could be effective to regulate the output of an MIC under uncertainties. Finally, this work studies the control of the MIMO dc-dc converter serving as an active distribution node in an intelligent dc distribution grid. The unified model of a MIMO converter is derived, enabling a systematical analysis and control design that allows this converter to control power flow in all its ports and to act as a power buffer that compensates for mismatches between power generation and consumption. Based on the derived high-order multivariable model, a robust controller is designed with disturbance-attenuation and pole-placement constraints via the linear matrix inequality (LMI) synthesis. The closed-loop robust stability and robust performance are tested through the structured singular value synthesis. Again, the desirable stability and performance are verified by simulations and experimental results.

Multiple-input Multiple-output Converters for Future Low-voltage DC Power Distribution Architectures

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

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Book Synopsis Multiple-input Multiple-output Converters for Future Low-voltage DC Power Distribution Architectures by : Yajian Tong

Download or read book Multiple-input Multiple-output Converters for Future Low-voltage DC Power Distribution Architectures written by Yajian Tong and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Modular Dc-dc Converters

Author : Faisal H. Khan
Publisher :
ISBN 13 :
Total Pages : 231 pages
Book Rating : 4.:/5 (18 download)

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Book Synopsis Modular Dc-dc Converters by : Faisal H. Khan

Download or read book Modular Dc-dc Converters written by Faisal H. Khan and published by . This book was released on 2007 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: DC-DC converter is one of the mostly used power electronic circuits, and it has applications in various areas ranging from portable devices to aircraft power system. Various topologies of dc-dc converters are suitable for different applications. In high power applications such as the bi-directional dc-dc converter for dual bus system in new generation automobiles, several topologies can be considered as a potential candidate. Regardless of the topology used for this application, the reliability of the converter can be greatly enhanced by introducing redundancy of some degree into the system. Using redundancy, uninterrupted operation of the circuit may be ensured when a fault has occurred. The redundancy feature can be obtained by paralleling multiple converters or using a single modular circuit that can achieve this attribute. Thus, a modular dc-dc converter with redundancy is expected to increase the reliability and reduce the system cost. Recently, the advancement in power electronics research has extended its applications in hybrid electric automobiles. Several key requirements of this application are reliable, robust, and high efficiency operation at low cost. In general, the efficiency and reliability of a power electronic circuit greatly depend on the kind of circuit topology used in any application. This is one of the biggest motivations for the researchers to invent new power electronic circuit topologies that will have significant impact in future automobile industry. This dissertation reviews existing modularity in power electronic circuits, and presents a new modular capacitor clamped dc-dc converter design that has many potential uses in future automotive power system. This converter has multilevel operation, and it is capable of handling bi-directional power. Moreover, the modular nature of the converter can achieve redundancy in the system, and thereby, the reliability can be enhanced to a great extent. The circuit has a high operating efficiency (>95%), and it is possible to integrate multiple voltage sources and loads at the same time. Thus, the converter could be considered as a combination of a power electronic converter and a power management system. In addition to the new dc-dc converter topology, a new pair of modular blocks defined as switching cells is presented in this dissertation. This pair of switching cells can be used to analyze many power electronic circuits, and some new designs can be formed using those switching cells in various combinations. Using these switching cells, many power electronic circuits can be made modular, and the modeling and analysis become easier.