Vector Control Of Three Phase Ac Machines

This book addresses the vector control of three-phase AC machines, in particular induction motors with squirrel-cage rotors (IM), permanent magnet synchronous motors (PMSM) and doubly-fed induction machines (DFIM), from a practical design and development perspective. The main focus is on the application of IM and PMSM in electrical drive systems, where field-orientated control has been successfully established in practice. It also discusses the use of grid-voltage oriented control of DFIMs in wind power plants. This second, enlarged edition includes new insights into flatness-based nonlinear control of IM, PMSM and DFIM. The book is useful for practitioners as well as development engineers and designers in the area of electrical drives and wind-power technology. It is a valuable resource for researchers and students.

The book deals with the problem area of the vector control of the three-phase AC machines like that one of the induction motor with squirrel-cage rotor (IMSR), the permanentmagnet excited synchronous motor (PMSM) and that one of the doubly fed induction machine (DFIM) from the view of the practical development. It is primarily about the use of the IMSR as well as the PMSM in the electrical drive systems, at which the method of the field-oriented control has been successful in the practice, and about the use of the grid voltage oriented controlled DFIM in the wind power plants. After a summary of the basic structure of a field-oriented controlled three-phase AC drive, the main points of the design and of the application are explained. The detailed description of the design rules forms the main emphasis of the book. The description is expanded and made understandable by numerous formulae, pictures and diagrams. Using the basic equations, first the continuous and then the discrete machine models of the IMSR as well as of the PMSM are derived. The vectorial two-dimensional current controllers, which are designed with help of the discrete models, are treated in detail in connection with other essential problems like system boundary condition and control variable limitation. Several alternative controller configurations are introduced. The voltage vector modulation, the field orientation and the coordinate transformations are treated also from the view of the practical handling. The problems like the parameter identification, parameter adaptation and the management of machine states, which are normally regarded as abstract, are so represented that the book reader does not receive only attempts but also comprehensible solutions for his system. The practical style in the description of the design rules of the drive systems are also continued consistently for the wind power systems using the DFIM. The represented control concept is proven practically and can be regarded as pioneering for new developments. The introduced control structures of the three machine types have led to a relatively mature stage of development in the practice. Some disadvantages have nevertheless remained at these linear control concepts, which have to be cleared only with nonlinear controllers. Going out from the structural nonlinearity of the machines, the suitable nonlinear models are derived. After that, nonlinear controllers are designed on the basis of the method of the "exact linearization" which proves to be the most suitable in comparison with other methods like "backstepping-based or passivity-based designs".

Vector control has become a powerful and frequently adopted technique in recent years. This book discusses in detail the various forms of vector control of smooth-air-gap and salient-pole electrical machines supplied by impressed stator voltages or currents or impressed rotary currents.

Electric drive systems is an area of great change and increasing commercial importance in industry today. Written by experts in the field, this book takes account of recent developments. These have been due largely to the advances in power electronics and computer control; in turn, they have made possible the implementation of a.c. drive systems, in place of d.c. Topics include inverter machine dynamics; constant speed behavior and the development of conventional equivalent circuits; vector controlled systems; and current regulators.

Alternating current (AC) induction and synchronous machines are frequently used in variable speed drives with applications ranging from computer peripherals, robotics, and machine tools to railway traction, ship propulsion, and rolling mills. The notable impact of vector control of AC drives on most traditional and new technologies, the multitude of practical configurations proposed, and the absence of books treating this subject as a whole with a unified approach were the driving forces behind the creation of this book. Vector Control of AC Drives examines the remarkable progress achieved worldwide in vector control from its introduction in 1969 to the current technology. The book unifies the treatment of vector control of induction and synchronous motor drives using the concepts of general flux orientation and the feed-forward (indirect) and feedback (direct) voltage and current vector control. The concept of torque vector control is also introduced and applied to all AC motors. AC models for drive applications developed in complex variables (space phasors), both for induction and synchronous motors, are used throughout the book. Numerous practical implementations of vector control are described in considerable detail, followed by representative digital simulations and test results taken from the recent literature. Vector Control of AC Drives will be a welcome addition to the reference collections of electrical and mechanical engineers involved with machine and system design.

Variable speed is one of the important requirements in most of the electric drives. Earlier dc motors were the only drives that were used in industries requiring - eration over a wide range of speed with step less variation, or requiring fine ac- racy of speed control. Such drives are known as high performance drives. AC - tors because of being highly coupled non-linear devices can not provide fast dynamic response with normal controls. However, recently, because of ready availability of power electronic devices, and digital signal processors ac motors are beginning to be used for high performance drives. Field oriented control or vector control has made a fundamental change with regard to dynamic perfo- ance of ac machines. Vector control makes it possible to control induction or s- chronous motor in a manner similar to control scheme used for the separately - cited dc motor. Recent advances in artificial intelligence techniques have also contributed in the improvement in performance of electric drives. This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the impro- ment of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on sensorless and direct torque control of electric drives as up-to date references in these topics are provided.

This book introduces electrical machine modeling and control for electrical engineering and science to graduate, undergraduate students as well as researchers, who are working on modeling and control of electrical machines. It targets electrical engineering students who have no time to derive mathematical equations for electrical machines in particular induction machine (IM) and doubly fed induction machines (DFIM). The main focus is on the application of field oriented control technique to induction motor (IM) and doubly fed induction motor (DFIM) in details, and since the induction motors have many drawback using this technique, therefore the application of a nonlinear control technique (feedback linearization) is applied to a reduced order model of DFIM to enhance the performance of doubly fed induction motor. Features Serves as text book for electrical motor modeling, simulation and control; especially modeling of induction motor and doubly fed induction motor using different frame of references. Vector control (field oriented control) is given in more detailed, and is applied to induction motor. A nonlinear controller is applied to a reduced model of an doubly induction motor associated with a linear observer to estimate the unmeasured load torque, which is used to enhance the performance of the vector control to doubly fed induction motor. Access to the full MATLAB/SIMULINK blocks for simulation and control.

This book constitutes the refereed proceedings of the 14th International Conference on Artificial Intelligence: Methodology, Systems, and Applications, AIMSA 2010, held in Varna, Bulgaria in September 2010.The 26 revised full papers presented together with the 13 posters were carefully reviewed and selected from 93 submissions. The papers are organized in topical sections on knowledge representation and reasoning; intelligent techniques for adaption, personalization, and recommendation; constraints and search; machine learning, data mining, and information retrieval; AI in education; applications.