Download or read book Efficient Modeling of Modular Multilevel HVDC Converters MMC on Electromagnetic Transient Simulation Programs written by Udana Gnanarathna and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent introduction of a new converter topology, the modular multilevel converter (MMC) is a major step forward in voltage sourced converter (VSC) technology for high voltage, high power applications. To obtain a multilevel ac output waveform, a large number of semiconductor switches has to be used in the converter. The number of switches in the MMC for HVDC transmission is typically two orders of magnitudes larger than that in a two or three level VSC used in earlier generation. This large device count creates a computational challenge for electromagnetic transients (EMT) simulation programs, as it significantly increases the simulation time. The purpose of this research is to investigate whether the simulation can be speeded up. This research develops an efficient, time-varying Thévenin's equivalent model for the MMC converter based on partitioning the system's admittance matrix. EMT simulation results show that the proposed equivalent model can drastically reduce the computational time without loss of accuracy. The use of the proposed equivalent method is demonstrated by simulating a point to point MMC based HVDC transmission system successfully with more than 100 levels. This approach enables what was hitherto not practical; the modeling of large MMC based HVDC systems on personal computers. With the assumption of ideal switch operation and using an equivalent average capacitor value based approach, an average valued model of MMC is also proposed in this thesis. The average model can be accurately used in most of the system level studies. The control algorithms and other modeling aspects of MMC applications are also presented in this thesis. One of the advantages of multilevel converters is the low operating losses as the smaller switching frequency of each individual power electronics switch and the low voltage step change during each switching. Using a recently developed, time domain simulation approach, the operating losses of the MMC converter are estimated in this thesis. When comparing the MMC operating losses against the losses of two-level VSC, the power loss for the two-level VSC is found to be significantly higher than the power loss of the MMC.

Download or read book Design Control and Application of Modular Multilevel Converters for HVDC Transmission Systems written by Kamran Sharifabadi and published by . This book was released on 2016 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modular Multilevel Converter Modelling and Simulation for HVDC Systems written by Davide del Giudice and published by Springer Nature. This book was released on 2022-10-21 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive review of the models and approaches that can be employed to simulate modular multilevel converters (MMCs). Each solution is described in terms of operating principle, fields of applicability, advantages, and limitations. In addition, this work proposes a novel and efficient simulation approach for MMCs based on sub-circuit isomorphism. This technique, which has its roots in the electronics fields, can be profitably exploited to simulate MMCs regardless of the model used to describe its sub-modules, including the most accurate ones. Lastly, this book considers a well-known high voltage direct current (HVDC) benchmark system consisting of two MMCs. After describing the implementation details of each benchmark component, simulation results in several scenarios (ranging from normal operating conditions to faults in the AC and DC grid) are included to validate the proposed approach and showcase its key features. Due to its educational content, this book constitutes a useful guide for PhD students and researchers interested in the topic of MMCs and their simulation. It also serves as a starting platform for junior electrical engineers who work in the field of power electronic converters for HVDC systems.

Download or read book Modular Multilevel Converters written by Sixing Du and published by John Wiley & Sons. This book was released on 2018-02-22 with total page 386 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.

Download or read book Analytical Efficiency Evaluation of Modular Multilevel Converter MMC for High Voltage Direct Current System HVDC written by Ehtasham Mustafa and published by GRIN Verlag. This book was released on 2016-02-25 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master's Thesis from the year 2014 in the subject Electrotechnology, University of Peshawar (University of Engineering and Technology, Peshawar, Pakistan), course: High Voltage Direct Current, language: English, abstract: Modular Multilevel Converter (MMC) has become the most concerned converter topology in the High Voltage Direct Current (HVDC) transmission system, in recent times. The low switching frequency, low converter losses and flexible control made it most attractive topology. It is important to make a research on the loss calculation method of MMC and state formulae for the losses as it is a vital step during the design stage of the MMC based HVDC system. In this research work, the structure of MMC based HVDC system is discussed. Three sub module topologies’; half bridge, full bridge and clamp double sub module, are discussed. A method based on the average and root mean square (RMS) values of the current passing through the sub module is discussed. The conversion losses in the switching devices of the sub modules are calculated using the method. A cases study is taken into consideration then with certain parameters. Using these parameters a MATLAB program is developed. With the help of the program the losses and efficiency curves for each switching device by taking each sub module separately are obtained respectively. A comparison of the losses and efficiency of each sub module is also discussed. At the end those factors which effect the losses and efficiency of the sub module are discussed along with the certain aspects for the directions of future work.

Download or read book Hybrid Cascaded Modular Multilevel Converters for HVDC Transmission written by Xianghua Shi and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a comprehensive study of a class of modular multilevel converters (MMCs) namely hybrid cascaded MMCs. These converters have topological dc-fault blocking capability and are suitable for large-scale, long-distance high-voltage direct current (HVDC) transmission. This thesis investigates an existing hybrid cascaded MMC (HC-MMC) and novel variations thereof (mixed-SM HC-MMC) with a multi-pronged research approach based upon mathematical analyses, detailed computer simulations, and where possible experimental verifications. Several methods are proposed for control and operation of the converter under normal and faulted conditions with a view to (i) enable regulation of submodule capacitor voltages in the phase limb with reduced harmonics and the ability of extending linear modulation range, (ii) ride through balanced and unbalanced ac faults with balanced phase currents and efficient ac-fault recovery, and (iii) successfully ride through dc faults with prompt isolation of the ac and dc sides and rapid decay of the dc fault current. These methods are extensively analyzed using detailed electromagnetic transient simulation and experimental work where possible. Converter losses and efficiency maps are also quantified using detailed computer modeling methods to evaluate the benefits of the existing and proposed HC-MMCs. Compared with the original HC-MMC, the proposed mixed-SM HC-MMC has superior performance in terms of extended linear modulation range, system efficiency, and dc-fault clearing performance. The thesis also formulates the design guidelines of SM capacitor sizing considering submodule redundancy and different control modes. Extensive analytical, simulation-based, and experimental measurements are provided to confirm the validity and efficacy of the developed guidelines.

Download or read book Reduced order Modeling of the Parallel Hybrid Modular Multilevel Converter written by Curtis Shumski and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the demand for electrical power continues to increase, so does the attractiveness of high voltage direct current (HVDC) transmission networks to transfer power from generating stations to load centers. Located at either end of the HVDC transmission network are converter stations that convert the AC power into DC power, and vice versa. A voltage source converter (VSC) commonly used in practice is the modular multilevel converter (MMC); however, these converters require many power electronic switches that will significantly increase the cost of such HVDC networks. A cost-effective alternative to these converters is the parallel hybrid MMC (PH-MMC), which is the focus of this thesis. Modeling VSCs in large electrical networks can be a computational burden as a small time step is required to capture all of the switching transients of the VSC. In some situations, it may not be necessary to simulate every switching instant, and instead a reduced-order model can be utilized. The reduced order model of VSCs retain the behavior of the converters, while being able to run at a larger time step and at a much faster simulation runtime. The basic principles of MMCs are first derived and the topological changes of the PH-MMC are analyzed. Comparisons between the PH-MMC and conventional MMCs are drawn to showcase the advantages and disadvantages of the PH-MMC. Control algorithms are described for basic operation of the PH-MMC, and control block diagrams are detailed to control the sub-module capacitor voltages as well as the AC terminal outputs. A qualitative fault analysis is provided for both AC and DC side faults, and a reduced-order model is developed to accurately model the PH-MMC in electromagnetic transient (EMT) studies by removing the need to model high frequency switching instants. Using a simple network model and a more complex network model, dynamic simulations are performed in PSCADTM/EMTDCTM software to validate the reduced-order model against the full, detailed switching model. Simulation results show that the developed reduced-order model is an accurate representation of the PH-MMC, while significantly decreasing the runtime to carry out such simulations as compared to the detailed model. When incorporating PH-MMCs into larger networks, the reduced-order model developed in this thesis can be used to alleviate the computational burden of using a small time step while maintaining the low frequency behavior of the converter.

Download or read book Real time Simulation of Modular Multilevel Converters written by Paradis Dominic and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Modular Multilevel Converters Using Extended frequency Dynamics Phasors written by Shailajah Rajesvaran and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates modeling of modular multilevel converters (MMCs) using an averaging method known as extended-frequency dynamic phasors. An MMC can be used as an inverter or a rectifier in high voltage direct current (HVDC) system. This research develops a dynamic phasor model for an MMC operated as an inverter. Extended-frequency dynamic phasors are used to model a system with only interested harmonics present. The developed model is capable of capturing both the low and high-frequency dynamic behavior of the converter depending on the requirements of the study to be performed. The selected MMC model has 5 submodules per arm (6-level converter), nearest level control, capacitor voltage balancing, direct control and phase-locked loop (PLL) synchronization. With the above features, the developed dynamic phasor model is validated with electromagnetic transient model is developed using PSCAD simulation software. The results are compared at transient and steady state with disturbances. The main computational advantage of this modeling is achieving less simulation time with inclusion of harmonics of interest.

Download or read book Efficient Modeling of Modular Multilevel Converters for HVDC Transmission Systems written by Noman Ahmed and published by . This book was released on 2018 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modular Multilevel Converters written by Fujin Deng and published by John Wiley & Sons. This book was released on 2023-03-29 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modular Multilevel Converters Expert discussions of cutting-edge methods used in MMC control, protection, and fault detection In Modular Multilevel Converters: Control, Fault Detection, and Protection, a team of distinguished researchers delivers a comprehensive discussion of fault detection, protection, and tolerant control of modular multilevel converters (MMCs) under internal and external faults. Beginning with a description of the configuration of MMCs, their operation principles, modulation schemes, mathematical models, and component design, the authors go on to explore output control, fault detection, capacitor monitoring, and other topics of central importance in the field. The book offers summaries of centralized capacitor voltage-balancing control methods and presents several capacitor monitoring methods, like the direct and sorting-based techniques. It also describes full-bridge and half-bridge submodule-based hybrid MMC protection methods and alternative fault blocking SM-based MMCs. Readers will also find: A thorough introduction to modular multilevel converters, including circuits, operation principles, modulation, mathematical models, components, and design constraints In-depth discussions of the control of modular multilevel converters, including output control, centralized capacitor voltage control, and individual capacitor voltage control Comprehensive explorations of fault detection of MMCs under IGBT faults, including short-circuit and open-circuit faults, as well as fault-tolerant control of MMCs Fulsome treatments of the control of MMCs under AC grid faults, including discussions of AC-side current control Perfect for electrical engineering researchers, Modular Multilevel Converters: Control, Fault Detection, and Protection, will also earn a place in the libraries of electrical engineers working in industry, as well as undergraduate and graduate students with an interest in MMCs.

Download or read book Real time Model and Simulation Architecture for Half and Full bridge Modular Multilevel Converters written by Mojtaba Ashourloo and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents an equivalent model and simulation architecture for real-time electromagnetic transient analysis of either half-bridge or full-bridge modular multilevel converter (MMC) with 400 sub-modules (SMs) per arm. The proposed CPU/FPGA-based architecture is optimized for the parallel implementation of the presented MMC model on the FPGA and is beneficiary of a high-throughput floating-point computational engine. The developed real-time simulation architecture is capable of simulating MMCs with 400 SMs per arm at 825 nanoseconds. To address the difficulties of the sorting process implementation, a modified Odd-Even Bubble sorting is presented in this work. The comparison of the results under various test scenarios reveals that the proposed real-time simulator is representing the system responses in the same way of its corresponding off-line counterpart obtained from the PSCAD/EMTDC program.

Download or read book Modeling and Control of Modular Multilevel Converter Based on Ordinary Differential Equations and Its Applications for HVDC System written by Haihao Jiang and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "High-voltage direct current (HVDC) system is more efficient than high-voltage alternating current (HVAC) system for long-distance, bulk power transmission. Modularity, flexibility, reliability and high efficiency make the modular multilevel converter (MMC) the topology of choice in HVDC applications. Because the increasing number of installations shows that the MMC-HVDC is the HVDC of the future, this thesis is continuing research to advance the capability of the MMC-HVDC. This thesis focuses on fast simulation capability and control strategies for the MMC-HVDC. The main objectives are: (1) to develop a fast and accurate simulation model of a single MMC station and models of multi-terminal MMC-HVDC stations (MTDC-MMC); (2) to investigate the method to design proper parameters for high damping; (3) to design the MMC-HVDC with the capability of power oscillation damping (POD). Simulation is computation-intensive in MMC. The thesis develops a fast and accurate method by which an MMC station is modeled by ordinary differential equations (ODE). The proposed MMC ODE model is implemented in MATLAB SIMULINK and its correctness is validated by the MMC Detail Equivalent Model (DEM) in RT-LAB. Taking advantage of its speed and accuracy, a Four-Terminal MMC-HVDC system based on the MMC ODE model is developed. The ODE model meets the speed and accuracy requirements of power systems engineers who are concerned with planning, operation and protection studies. As the ordinary differential equations are nonlinear, small perturbation about a steady-state is applied to obtain the linearized time-periodic matrix. The steady-state takes a long time to simulate because it depends on the transients to have all damped out. The method of Aprille and Trick is applied. Simulation converges to the steady-state in one cycle of 50 Hz. The resultant linearized matrix is time-periodic. The Floquet-Lyapunov Theorem is applied to construct the state-transition matrix from the linearized time-periodic matrix. The eigenvalues of the state-transition matrix contain the coefficients of damping. Graphs of damping coefficients plotted against different sizes of circuit parameters are displayed to assist designers in realizing high damping. The thesis looks for opportunities to add value to the MMC-HVDC. The active power transmissibility of AC transmission lines is limited by the transient stability limit which is significantly below the thermal limit. Extensive research and development have been pursued to increase the transient stability limit by flexible AC transmissions system (FACTS). This thesis seeks to use the MMC-HVDC to operate as power oscillation damper to increase the power transmissibility. The thesis looks for opportunities to integrate previously proven control methods into a common universal control. The Universal Controller brings together the deadbeat control, the circulating current suppression control (CCSC), the POD and the decoupled P-Q strategy in the control of the MMC-HVDC station by the MMC ODE model. Deadbeat control enables the MMC to survive destructively large AC fault currents to improve the transient stability of AC grids"--

Download or read book Modular Multilevel Converters for Electric Transportation Applications written by Deepak Ronanki and published by Wiley. This book was released on 2025-01-21 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive overview of the fundamentals, the technical challenges, and the control aspects of modular multilevel converters Modular multilevel converters (MMCs) have emerged in recent years as the newest breed of multilevel converters, and have received wide acceptance both in industry and academia. The benefits and desirable features of MMCs are manifold: modularity, high-quality output waveforms, absence of dc-link capacitance, and lower electromagnetic interference. MMCs rely on transformerless operation and can be a multi-motor operation, so it can be scaled to higher power and voltage levels—resulting in high efficiency—and tolerate faults to a greater degree than other systems. Modular Multilevel Converter offers a uniquely wide range of topics relating to MMCs, from electrical machines, to control theory, to electronics and power electronics. The book provides the reader with information to strengthen their understanding of basic concepts, as well as the latest technologies in propulsion systems, power supplies, and battery charging infrastructure. The scope of this resource is comprehensive with detailed discussions on different submodule design, diverse modeling approach, pulse width modulation schemes, and voltage balancing methods. It also examines charge-balancing control techniques, circulating current suppressing control schemes, and reliability enhancement features. Most significantly, the text reflects the latest technologies in electric transportation—electric railway traction, battery-charging infrastructure, and marine applications—and is aligned to current industry requirements. Modular Multilevel Converter readers will also find: Discussion of the fundamentals and important concepts with the simulations in PLECS® platform and OPAL-RT® real-time digital simulator. Coverage of the global standards such as IEC and IEEE for each application and their requirements A series of case studies that highlight aspects of MMC application A companion website that provides self-explanatory demo-simulation models of MMC with different variants of carrier-based pulse width modulation schemes Modular Multilevel Converter isa useful reference for academic researchers, design engineers, graduate courses, and other professionals in the field of electric transportation.

Download or read book Modular Multilevel Converters with Embedded Storage written by Nuwan Madushanka Herath Herath Mudiyanselage and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modular multilevel converters with embedded storage (MMC-ES) have attracted the attention of researchers as a flexible converter of integrating energy storage to ac and dc networks using a single converter. Conventional EMT simulation methods are highly inefficient in simulating MMC-ES due to the large number of switching elements in the converter. Detailed equivalent model (DEM) have been developed in previous research that could efficiently simulate the MMC-ES, but are ineffective in mathematically analysing the converter. This thesis proposes a novel averaged-value model (AVM) to the MMC-ES multivalve, which simulates the converter based on multivalve averaged quantities. The model is capable of conducting general EMT simulations, and analytically estimating circulating currents and capacitor voltage ripple. The AVM is validated against detailed EMT simulation results, mathematical analysis, and laboratory prototype observations. The thesis also improves the AVM and DEM to simulate converter's blocking state and validates the models against detailed simulation model. A novel MMC-ES HVDC link startup procedure is also developed and verified. Two case studies are conducted to study the use of MMC-ES in providing extensive ancillary services and it is concluded that MMC-ES supported by dedicated measurement communication lines and conventional fast frequency response controllers could greatly improve network frequency response.

Download or read book A Dynamic Phasor Model of a Modular Multilevel Converter for EMT Co simulation written by Rupasinghe Arachchige Tharinda Janesh Kumar Rupasinghe and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a new dynamic phasor model of a modular multilevel converter (MMC), which can be used for electromagnetic transient (EMT) simulation studies. The model is extendable to capture and replicate any given number of harmonics of the output waveforms and also it produces the most dominant frequency components of internal capacitor voltages and arm currents waveforms. The internal dynamics of the MMC are modeled using the conventional dynamic phasor (CDP) principles in form of a linear state equation system. Solution of the state equations, which is obtained via numerical integration, is then used to build the dynamics of output voltage waveforms of the MMC by applying a new concept referred to as base-frequency dynamic phasors (BFDP). Validation results illustrate that the new MMC model is much more computationally efficient than other two models and is also capable of maintaining a high level of accuracy.

Download or read book Analytical Modeling for Evaluation of Efficiency and Fault Transients of Modular Multilevel Converter in HVDC Systems written by Peng Wang and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: