Model Predictive Critical Soft Switching Enabling High Performance Software Defined Power Electronics

Leveraging the hierarchical control architecture and software-defined power electronics, the repetitive power converter hardware components and software algorithms design procedures can be simplified and standardized. Also, for different power converter applications, the efficiency and power density are both improved with better dynamic performance.

In this original book on model predictive control (MPC) for power electronics, the focus is put on high-power applications with multilevel converters operating at switching frequencies well below 1 kHz, such as medium-voltage drives and modular multi-level converters. Consisting of two main parts, the first offers a detailed review of three-phase power electronics, electrical machines, carrier-based pulse width modulation, optimized pulse patterns, state-of-the art converter control methods and the principle of MPC. The second part is an in-depth treatment of MPC methods that fully exploit the performance potential of high-power converters. These control methods combine the fast control responses of deadbeat control with the optimal steady-state performance of optimized pulse patterns by resolving the antagonism between the two. MPC is expected to evolve into the control method of choice for power electronic systems operating at low pulse numbers with multiple coupled variables and tight operating constraints it. Model Predictive Control of High Power Converters and Industrial Drives will enable to reader to learn how to increase the power capability of the converter, lower the current distortions, reduce the filter size, achieve very fast transient responses and ensure the reliable operation within safe operating area constraints. Targeted at power electronic practitioners working on control-related aspects as well as control engineers, the material is intuitively accessible, and the mathematical formulations are augmented by illustrations, simple examples and a book companion website featuring animations. Readers benefit from a concise and comprehensive treatment of MPC for industrial power electronics, enabling them to understand, implement and advance the field of high-performance MPC schemes.

This book focuses on Model Predictive Control (MPC) of discrete-time hybrid systems. Hybrid systems contain continuous and discrete valued components, and are located at the intersection between the fields of control theory and computer science. MPC uses an internal model of the controlled plant to predict the future evolution of the controlled variables over a prediction horizon. A cost function is minimized to obtain the optimal control input sequence, which is applied to the plant by means of a receding horizon policy. The latter implies that only the first control input of the input sequence is implemented, the horizon is shifted by one time-step and the above procedure is repeated at the next sampling instant. Most importantly, theory and tools are available to off-line derive the piecewise affine (PWA) state-feedback control law. Hence, any time-consuming on-line computation of the control input is avoided and plants with high sampling frequencies can be controlled. The book is divided into two parts: The first part is devoted to theory and algorithms, whereas the second part tackles applications in the fields of power electronics and power systems. In the first part, using the notion of cell enumeration in hyperplane arrangements from computational geometry, we propose an algorithm that efficiently enumerates all feasible modes of a composition of hybrid systems. This technique allows the designer to evaluate the complexity of the compound model, to efficiently translate the model into a PWA representation, and to reduce the computational burden of optimal control schemes by adding cuts that prune infeasible modes from the model. With respect to implementation, an important issue is the complexity reduction of PWA state-feedback controllers. Hence, we propose two algorithms that solve the problem of deriving a PWA representation that is both equivalent to the given one and minimal in the number of regions. As both algorithms refrain from solving additional Linear Programs, they are not only optimal but also computationally feasible. In many cases, the optimal complexity reduction constitutes an enabling technique when implementing the optimal controllers as look-up tables in hardware. In the second part of the book, we consider the field of power electronics that is intrinsically hybrid, since the positions of semiconductor switches are described by binary variables. %Furthermore, hard constraints and nonlinearities are often present. The fact that the methodologies of MPC and hybrid systems are basically unknown in the power electronics community has motivated us to consider such problems, namely switch-mode DC-DC converters and induction machines driven by three-phase inverters using the notion of Direct Torque Control (DTC). For these problems, we propose novel modelling and control schemes that are conceptually simple, easy to devise, understand and tune, and most importantly, implementable. Specifically for DTC, we present a low complexity modelling approach of the induction machine, based on which we propose three novel Model Predictive Control (MPC) approaches to tackle the DTC problem, namely MPC based on Priority Levels, MPC based on Feasibility and Move Blocking, and MPC based on Extrapolation. In particular the third control scheme is expected to be implementable, what has motivated our industrial partner to protect the scheme by a patent. Considering the synchronous step-down DC-DC converter as an illustrative example for DC-DC converters, we derive a hybrid model of the converter that is valid for the whole operating regime, and for which we formulate and solve off-line an MPC problem leading to a state-feedback control law parameterized over the whole state-space. The analysis of the controller shows that the considered state-space is control invariant, and that the nominal closed-loop system is globally exponentially stable what is proved by a piecewise quadratic (PWQ) Lyapunov function. Moreover, the controller rejects large disturbances in the input voltage and the load. Alike power electronics, power systems possess many hybrid features including integer manipulated variables such as load-shedding and capacitor switching, and internal controllers based on logic and finite state machines such as tap changers in transformers. Motivated by the recent severe blackouts in the US and Europe, we propose an emergency voltage control scheme that stabilizes the voltages in spite of major outages in order to prevent a voltage collapse and a blackout. To avoid unnecessary disruptive control actions, the control moves are classified into nominal and emergency control actions, and corresponding penalty levels are used in the objective function triggering disruptive control moves such as load-shedding only if absolutely necessary.

Provides comprehensive coverage of the basic principles and methods of electric power conversion and the latest developments in the field This book constitutes a comprehensive overview of the modern power electronics. Various semiconductor power switches are described, complementary components and systems are presented, and power electronic converters that process power for a variety of applications are explained in detail. This third edition updates all chapters, including new concepts in modern power electronics. New to this edition is extended coverage of matrix converters, multilevel inverters, and applications of the Z-source in cascaded power converters. The book is accompanied by a website hosting an instructor’s manual, a PowerPoint presentation, and a set of PSpice files for simulation of a variety of power electronic converters. Introduction to Modern Power Electronics, Third Edition: Discusses power conversion types: ac-to-dc, ac-to-ac, dc-to-dc, and dc-to-ac Reviews advanced control methods used in today’s power electronic converters Includes an extensive body of examples, exercises, computer assignments, and simulations Introduction to Modern Power Electronics, Third Edition is written for undergraduate and graduate engineering students interested in modern power electronics and renewable energy systems. The book can also serve as a reference tool for practicing electrical and industrial engineers.

Power electronics, which is a rapidly growing area in terms of research and applications, uses modern electronics technology to convert electric power from one form to another, such as ac-dc, dc-dc, dc-ac, and ac-ac with a variable output magnitude and frequency. Power electronics has many applications in our every day life such as air-conditioners, electric cars, sub-way trains, motor drives, renewable energy sources and power supplies for computers. This book covers all aspects of switching devices, converter circuit topologies, control techniques, analytical methods and some examples of their applications. * 25% new content* Reorganized and revised into 8 sections comprising 43 chapters* Coverage of numerous applications, including uninterruptable power supplies and automotive electrical systems* New content in power generation and distribution, including solar power, fuel cells, wind turbines, and flexible transmission

This book deals with quantifying and analyzing the risks associated with sustainable energy technology growth in electric power systems, and developing appropriate models and methodologies to mitigate the risks and improve the overall system performance. The rapid increase in the installation of renewable energy sources in electric power systems has given rise to a wide range of problems related to planning and operation of power systems to maintain quality, stability, reliability and efficiency. Additionally, there is a growing global environmental concern regarding increasing emissions from the electric power generation required to meet rising energy needs and support sustainable and inclusive development. The phenomenon of low voltage ride through (LVRT), common to wind energy systems, is discussed, and ways to tackle the same are proposed in the first chapter. Subsequent chapters propose methods of optimizing a sustainable and smart microgrid, and supplying electricity to remote areas of a developing country with no immediate possibility of national grid extension. The economic benefit and technical challenges of forming localized minigrid are also discussed. The book proposes a method for reliability assessment of a power grid with sustainable power transportation system. The issue of weak link in power system is very important as it will provide the system operators and planners to take necessary measures to strengthen the system. An approach to determine the weak parts of the system and its unreliability is proposed. With increasing installation of HVDC power transmission and development of efficient and low cost power electronic devices, the DC microgrids are becoming a common phenomenon. Their existence together with AC Grids result in Hybrid AC/DC Microgrids, which are discussed in this book. It further presents a method for reliability evaluation of a distribution system with network reconfiguration in the presence of distributed generation. The important problems in sustainable energy growth, and their potential solutions discussed and presented in the book should be of great interest to engineers, policy makers, researchers and academics in the area of electric power engineering.

The authors were originally brought together to share research and applications through the international Danfoss Professor Programme at Aalborg University in Denmark. Personal computers would be unwieldy and inefficient without power electronic dc supplies. Portable communication devices and computers would also be impractical. High-performance lighting systems, motor controls, and a wide range of industrial controls depend on power electronics. In the near future we can expect strong growth in automotive applications, dc power supplies for communication systems, portable applications, and high-end converters. We are approaching a time when all electrical energy will be processed and controlled through power electronics somewhere in the path from generation to end use. The most up-to-date information available is presented in the text Written by a world renowned leader in the field

Power electronics technology is still an emerging technology, and it has found its way into many applications, from renewable energy generation (i.e., wind power and solar power) to electrical vehicles (EVs), biomedical devices, and small appliances, such as laptop chargers. In the near future, electrical energy will be provided and handled by power electronics and consumed through power electronics; this not only will intensify the role of power electronics technology in power conversion processes, but also implies that power systems are undergoing a paradigm shift, from centralized distribution to distributed generation. Today, more than 1000 GW of renewable energy generation sources (photovoltaic (PV) and wind) have been installed, all of which are handled by power electronics technology. The main aim of this book is to highlight and address recent breakthroughs in the range of emerging applications in power electronics and in harmonic and electromagnetic interference (EMI) issues at device and system levels as discussed in ‎robust and reliable power electronics technologies, including fault prognosis and diagnosis technique stability of grid-connected converters and ‎smart control of power electronics in devices, microgrids, and at system levels.