Converter Applications And Their Influence On Large Electrical Machines

Converter driven applications are applied in more and more processes. Almost any installed wind-farm, ship drives, steel mills, several boiler feed water pumps, extruder and many other applications operate much more efficient and economic in case of variable speed solutions. The boundary conditions for a motor or generator will change, if it is supplied by a converter. An electrical machine, which is operated by a converter, can no longer be regarded as an independent component, but is embedded in a system consisting of converter and machine. This book gives an overview of existing converter designs for large electrical machines. Methods for the appropriate calculation of machine phenomena, which are implied by converters are derived in the power range above 500kVA. It is shown how due to the converter inherent higher voltage harmonics and pulse frequencies special phenomena are caused inside the machine which can be the reason for malfunction. It is demonstrated that additional losses create additional temperature increases or voltage peaks. The book describes how torque ripple can occur, which endanger the mechanical shaft system and last but not least shaft voltages are induced, which are sometimes sufficient in amplitude to damage bearings or to disturb sensors of the protection arrangements.

This thesis gives an overview of test bench design for inverter operated Medium Voltage (MV) drives with the focus on the active power measurement. The sources of measurement setup uncertainty are analysed and methods are shown to assess these uncertainties. Further, a possibility is shown to do quantitative uncertainty estimations which are verified with measurements through different measurement setups for MV drives operated with multilevel converters. The influence of measurement transducers, voltage dividers, power meters and data acquisition boards are considered. The digital signal processing is analysed and the possibilities to reduce its uncertainty contribution on an active power measurement is shown. An analysis is made with the conventional measurement devices in the MV-range. The transfer behaviour of the devices and the characteristics of the uncertainty are investigated. Measurements are done on typical medium voltage drives with an uncertainty analysis, which shows the essential aspects of active power measurement. The results show the significance of a measurement setup performance. The investigations on the drives are used to indicate the impact on the determination of the drive efficiency and gives a significant input for further standardisation processes. The handling of measurement uncertainties during active power measurement of drives is shown concerning the permanent topic of energy saving and its efficient use. The work proposes a way of categorising electrical drives in energy efficiency classes and to make their determination comparable. Die vorliegende Dissertation gibt einen Überblick über den Prüfstandsaufbau von umrichtergetriebenen Mittelspannungsantrieben. Die Unsicherheitsquellen werden analysiert und Methoden werden aufgezeigt um die Messunsicherheit zu bewerten. Des Weiteren werden die Machbarkeit von Unsicherheitsabschätzungen gezeigt, welche mit Messungen an typischen Mittelspannungsantrieben mit Umrichterspeisung verglichen werden. Der Einfluss von Messwandlern, Spannungsteilern, Leistungsmessern und Messkarten zur Signalerfassung wird berücksichtigt. Die digitale Signalverarbeitung wird analysiert um den Unsicherheitsbeitrag zur Wirkleistungsmessung zu reduzieren. Es werden konventionellen Messwandler und -teiler im Mittelspannungsbereich bezüglich ihres Übertragungsverhal- tens sowie Messunsicherheiten untersucht. Die Ergebnisse der Untersuchungen verdeutlichen die Signifikanz eines performanten Messaufbaus. Des Weiteren werden Auswirkun- gen auf die Bestimmung der Effizienz aufgezeigt. Die Arbeit liefert einen wesentlichen Beitrag für weitere Standardisierungsprozesse. Der Umgang mit Messunsicherheiten der Wirkleistungsmessung wird betrachtet im Hinblick auf Energieeinsparpotenziale und deren effiziente Nutzung. Die Arbeit schlägt eine Möglichkeit vor, wie elektrische Antriebe in Energieeffizienzklassen kategorisiert werden können um diese vergleichbar zu machen.

This book highlights recent findings in industrial, manufacturing and mechanical engineering, and provides an overview of the state of the art in these fields, mainly in Russia and Eastern Europe. A broad range of topics and issues in modern engineering are discussed, including the dynamics of machines and working processes, friction, wear and lubrication in machines, surface transport and technological machines, manufacturing engineering of industrial facilities, materials engineering, metallurgy, control systems and their industrial applications, industrial mechatronics, automation and robotics. The book gathers selected papers presented at the 6th International Conference on Industrial Engineering (ICIE), held in Sochi, Russia in May 2020. The authors are experts in various fields of engineering, and all papers have been carefully reviewed. Given its scope, the book will be of interest to a wide readership, including mechanical and production engineers, lecturers in engineering disciplines, and engineering graduates.

In modern industries, electrical energy conversion systems consist of two main parts: electrical machines and power electronic converters. With global electricity use at an all-time high, uninterrupted operation of electrical power converters is essential. Reliability in Power Electronics and Electrical Machines: Industrial Applications and Performance Models provides an in-depth analysis of reliability in electrical energy converters as well as strategies for designing dependable power electronic converters and electrical machines. Featuring a comprehensive discussion on the topics of reliability design and measurement, failure mechanisms, and specific issues pertaining to quality, efficiency, and durability, this timely reference source offers practical examples and research-based results for use by engineers, researchers, and advanced-level students.

This book endeavors to break the stereotype that basic electrical machine courses are limited only to transformers, DC brush machines, induction machines, and wound-field synchronous machines. It is intended to serve as a textbook for basic courses on Electrical Machines covering the fundamentals of the electromechanical energy conversion, transformers, classical electrical machines, i.e., DC brush machines, induction machines, wound-field rotor synchronous machines and modern electrical machines, i.e., switched reluctance machines (SRM) and permanent magnet (PM) brushless machines. In addition to academic research and teaching, the author has worked for over 18 years in US high-technology corporative businesses providing solutions to problems such as design, simulation, manufacturing and laboratory testing of large variety of electrical machines for electric traction, energy generation, marine propulsion, and aerospace electric systems.

Traditionally, electrical machines are classi?ed into d. c. commutator (brushed) machines, induction (asynchronous) machines and synchronous machines. These three types of electrical machines are still regarded in many academic curricula as fundamental types, despite that d. c. brushed machines (except small machines) have been gradually abandoned and PM brushless machines (PMBM) and switched reluctance machines (SRM) have been in mass p- duction and use for at least two decades. Recently, new topologies of high torque density motors, high speed motors, integrated motor drives and special motors have been developed. Progress in electric machines technology is stimulated by new materials, new areas of applications, impact of power electronics, need for energy saving and new technological challenges. The development of electric machines in the next few years will mostly be stimulated by computer hardware, residential and public applications and transportation systems (land, sea and air). At many Universities teaching and research strategy oriented towards el- trical machinery is not up to date and has not been changed in some co- tries almost since the end of the WWII. In spite of many excellent academic research achievements, the academia–industry collaboration and technology transfer are underestimated or, quite often, neglected. Underestimation of the role of industry, unfamiliarity with new trends and restraint from technology transfer results, with time, in lack of external ?nancial support and drastic - cline in the number of students interested in Power Electrical Engineering.

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.

Power converters and electric machines represent essential components in all fields of electrical engineering. In fact, we are heading towards a future where energy will be more and more electrical: electrical vehicles, electrical motors, renewables, storage systems are now widespread. The ongoing energy transition poses new challenges for interfacing and integrating different power systems. The constraints of space, weight, reliability, performance, and autonomy for the electric system have increased the attention of scientific research in order to find more and more appropriate technological solutions. In this context, power converters and electric machines assume a key role in enabling higher performance of electrical power conversion. Consequently, the design and control of power converters and electric machines shall be developed accordingly to the requirements of the specific application, thus leading to more specialized solutions, with the aim of enhancing the reliability, fault tolerance, and flexibility of the next generation power systems.