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Reluctance Electric Machines : Design and Control pdf


Reluctance Electric Machines : Design and Control.

Preface: Electric energy is arguably a key agent for our material prosperity. With the notable exception of photovoltaic generators, electric generators are exclusively used to produce electric energy from mechanical energy. Also, more than 60% of all electric energy is used in electric motors for useful mechanical work in various industries. 

Renewable energy conversion is paramount in reducing the CO2 quantity per kWh of electric energy and in reducing the extra heat on Earth. 

Electrical permanent magnet machines developed in the last two decades with torques up to the MNm range are showing higher efficiency for smaller weights. However, the temptation to use them in all industries—from wind and hydro generators; to ships, railroad, automotive, and aircraft propulsion (integral or assisting); to small electric drives in various industries with robotics, home appliances, and info-gadgets has led recently to a strong imbalance between high–specific energy magnet demand and supply, which has been “solved” so far mainly by stark increases in the price of high-quality permanent magnets (PMs). 

In an effort to produce high-performance electric motors and generators, as well as drives for basically all industries, but mainly for renewable energy conversion, electric mobility, robotics and so on, the variable reluctance concept in producing torque in electric machines, eventually assisted by lower-total-cost PMs, has shown a spectacular surge in research and development (R&D) worldwide in the last two decades. 

The extension of electric machines to lower-speed applications—with less or no mechanical transmission—in an effort to keep performance high but reduce initial and maintenance costs has found a strong tool in the variable reluctance concept; it aims to produce electromagnetic torque (and power) by creating strong magnetic anisotropies in electric machines (rather than by PM- or direct current (DC)-excited or induced-current rotors). 

Though the principle of the variable reluctance motor was patented in the late nineteenth century, it was not until power electronics developed into a mature industry in the 1970s that reluctance electric machines became a strong focus point in R&D and industry. Delayed by the spectacular advent of PM electric machines for a few decades, only in the last 10 years have reluctance electric machines enjoyed increased attention. Very recently, such reluctance synchronous motor drives for variable speeds have reached mass production from 10 kW to 500 kW. 

Given the R&D results so far and the current trends in the industry, reluctance electric machines and drives are expected to penetrate most industries. 

Because of this, we believe an overview of recent progress with classifications, topologies, principles, modeling for design, and control is timely, and this is what the present monograph intends to do.

After an introductory chapter (Chapter 1), the book is divided into two parts:

Part 1. One- and three-phase reluctance synchronous motors in line-start (constant speed) and then in variable-speed applications, with PM assistance to increase efficiency at moderate extra initial cost and in variable-speed drives (Chapters 2 through 5).

Part 2. Reluctance motors and generators in pulse width modulation (PWM) converter-fed variable speed drives, where high efficiency at a moderate power factor and moderate initial system and ownership costs are paramount (Chapters 6 through 14).

Part 2 includes a myriad of topologies under the unique concept of flux modulation and includes:

• Claw pole rotor synchronous motors, Chapter 6

• Brushless DC–multiple phase reluctance machines (BLDC-MRMs), Chapter 7

• Brushless doubly fed reluctance machines (BDFRMs), Chapter 8

• Switched flux PM synchronous machines (SF-PMSMs), Chapter 9

• Flux reversal PMSMs (FR-PMSMs), Chapter 10

• Vernier PM machines, Chapter 11

• Transverse-flux PMSMs (TF-PMSMs), Chapter 12

• Magnetic-gear dual-rotor reluctance electric machines (MG-REMs), Chapter 13

• DC+alternating current (AC) doubly salient electric machines, Chapter 14

The structure of all chapters is unitary to treat:

• Topologies of practical interest.

• Principles, basic modeling, performance, and preliminary design with numerical examples.

• Advanced modeling by magnetic equivalent circuit (MEC) with analytical optimal design (AOD).

• Key finite elements method (FEM) validation of AOD or direct FEM-based geometrical optimization design.

• Basic and up-to-date control of electric motors and generators with and without encoders.

• Sample representative results from recent literature and from authors’ publications are included in all chapters.

hough it is a monograph, the book is conceived with self-sufficient chapters and thus is suitable to use as a graduate textbook and a design assistant for electrical, electronics, and mechanical engineers in various industries that investigate, design, fabricate, test, commission, and maintain electric motorgenerator drives in most industries that require digital motion (energy) control to reduce energy consumption and increase productivity.

Download Reluctance Electric Machines : Design and Control by Ion Boldea and Lucian Tutelea.

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