Permanent Magnet Spherical Motors

This book introduces and illustrates modeling, sensing, and control methods for analyzing, designing, and developing spherical motors. It systematically presents models for establishing the relationships among the magnetic fields, position/orientation and force/torque, while also providing time-efficient solutions to assist researchers and engineers in studying and developing these motors. In order to take full advantage of spherical motors’ compact structure in practical applications, sensing and control methods that utilize their magnetic fields and eliminate the need to install external sensors for feedback are proposed. Further, the book investigates for the first time spherical motors’ force/torque manipulation capability, and proposes algorithms enabling the ball-joint-like end-effector for haptic use based on these motors’ hybrid position/force actuation modes. While systematically presenting approaches to their design, sensing and control, the book also provides many examples illustrating the implementation issues readers may encounter.

The importance of permanent magnet (PM) motor technology and its impact on electromechanical drives has grown exponentially since the publication of the bestselling second edition. The PM brushless motor market has grown considerably faster than the overall motion control market. This rapid growth makes it essential for electrical and electromechanical engineers and students to stay up-to-date on developments in modern electrical motors and drives, including their control, simulation, and CAD. Reflecting innovations in the development of PM motors for electromechanical drives, Permanent Magnet Motor Technology: Design and Applications, Third Edition demonstrates the construction of PM motor drives and supplies ready-to-implement solutions to common roadblocks along the way. This edition supplies fundamental equations and calculations for determining and evaluating system performance, efficiency, reliability, and cost. It explores modern computer-aided design of PM motors, including the finite element approach, and explains how to select PM motors to meet the specific requirements of electrical drives. The numerous examples, models, and diagrams provided in each chapter facilitate a lucid understanding of motor operations and characteristics. This 3rd edition of a bestselling reference has been thoroughly revised to include: Chapters on high speed motors and micromotors Advances in permanent magnet motor technology Additional numerical examples and illustrations An increased effort to bridge the gap between theory and industrial applications Modified research results The growing global trend toward energy conservation makes it quite possible that the era of the PM brushless motor drive is just around the corner. This reference book will give engineers, researchers, and graduate-level students the comprehensive understanding required to develop the breakthroughs that will push this exciting technology to the forefront.

Co-authored by a world-renowned expert in the field, Permanent Magnet Motor Technology: Design and Applications, Second Edition demonstrates the construction of PM motor drives and supplies ready-to-implement solutions for common roadblocks. The author presents fundamental equations and calculations to determine and evaluate system performance, efficiency, and reliability; explores modern computer-aided design of PM motors, including the finite element approach; and covers how to select PM motors to meet the specific requirements of electrical drives. The numerous examples, models, and diagrams provided in each chapter give the reader a clear understanding of motor operations and characteristics.

The late 1980s saw the beginning of the PM brushless machine era, with the invention of high-energy density permanent magnets (PM) and the development of power electronics. Although induction motors are now the most popular electric motors, the impact of PM brushless machines on electromechanical drives is significant. Today, PM machines come second to induction machines. Replacement of electromagnetic field excitation systems by PMs brings the following benefits: No electrical energy is absorbed by the field excitation system and thus there are no excitation losses, causing substantial increase in efficiency Higher power density (kW/kg) and/or torque density (Nm/kg) than electromagnetic excitation Better dynamic performance than motors with electromagnetic excitation (higher magnetic flux density in the air gap) Simplification of construction and maintenance Less expensive for some types of machines Modern Permanent Magnet Electric Machines: Theory and Control serves as a textbook for undergraduate power engineering students who want to supplement and expand their knowledge in the fundamentals of magnetism, soft magnetic materials, permanent magnets (PMs), calculation of magnetic circuits with PMs, modern PM brushed DC machines and their controls, modern PM brushless DC motors and drive control, and modern PM generators. The book can help students learn more about electrical machines and can serve as a prescribed text for teaching elective undergraduate courses such as modern permanent magnet electrical machines. Since the book is written in a simple scientific language and without redundant mathematics, it can also be used by practicing engineers and managers employed in electrical machinery or electromagnetic device industries.

Permanent magnet synchronous (PMS) motors stand at the forefront of electric motor development due to their energy saving capabilities and performance potential. The motors have been developed in response to mounting environmental crises and growing electricity prices, and they have enabled the emergence of motor drive applications like those found in electric and hybrid vehicles, fly by wire, and drones. Control of Permanent Magnet Synchronous Motors is a timely advancement along that path as the first comprehensive, self-contained, and thoroughly up-to-date book devoted solely to the control of PMS motors. It offers a deep and extended analysis, design, implementation, and performance evaluation of major motor control methods, including Vector, Direct Torque, Predictive, Deadbeat, and Combined Control, in a systematic and coherent manner. All major Sensorless Control and Parameter Estimation methods are also studied. The book places great emphasis on energy saving control schemes.

A spherical actuator is a novel electric device that can achieve 2/3-DOF rotational motions in a single joint with electric power input. It has advantages such as compact structure, low mass/moment of inertia, fast response and non-singularities within the workspace. It has promising applications in robotics, automobile, manufacturing, medicine and aerospace industry. This is the first monograph that introduces the research on spherical actuators systematically. It broadens the scope of actuators from conventional single-axis to multi-axis, which will help both beginners and researchers to enhance their knowledge on electromagnetic actuators. Generic analytic modeling methods for magnetic field and torque output are developed, which can be applied to the development of other electromagnetic actuators. A parametric design methodology that allows fast analysis and design of spherical actuators for various applications is proposed. A novel non-contact high-precision 3-DOF spherical motion sensing methodology is developed and evaluated with experiments, which shows that it can achieve one order of magnitude higher precision than conventional methods. The technologies of nondimensionalization and normalization are introduced into magnetic field analysis the first time, and a benchmark database is established for the reference of other researches on spherical actuators.

Written for electrical, electronics, & mechanical engineers responsible for designing & specifying motors, the book provides details of brushless DC & synchronous motors, as well as both radial & axial motor topologies. Beginning with a discussion of the fundamentals of generic motor design, it logically progresses to a set of more advanced, yet easily understandable, concepts for designing brushless permanent-magnet motors. In addition, the author fully explains techniques for magnetic modeling & circuit analysis, shows how magnetic circuit analysis applies to motor design, describes all major aspects of motor operation & design in simple mathematical terms, develops rigorous design equations for radial flux & axial flux motors, & illustrates basic motor drive schemes. All common motor design terms are clearly defined & a wealth of charts, tables & equations are included.

No standard work of reference, dealing with dc linear motor in all its aspects has ever been published. However, a considerable amount of literature in the form of published papers dealing with this subject, and also an amount of hitherto unpublished work, particularly of an industrial or applied nature, has been accumulated during the last 25 years. An attempt has been made to collate all this information and present it in a comprehensive and orderly manner in this unique volume. This book has been designed to be useful to two main categories of readers, namely, electrical and mechanical engineers in the user industries, and post-graduates and students embracing mechanical and electrical engineers.