Principles Of Electrical Machines By V.K. Mehta

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Principles of Electrical Machines By V.K. Mehta

"Principles of Electrical Machines" by V.K. Mehta (and often co-authored with Rohit Mehta) is a popular and widely-used textbook for undergraduate students in electrical and electronics engineering, particularly in India and other parts of South Asia.

Principles of Electrical Machines Author: V.K. Mehta & Rohit Mehta

Principles of Electrical Machines Publisher: S. Chand Publishing

Principles of Electrical Machines Suitable For: Diploma Engineering , B.Sc Engineering , Competitive Exam

Overview

Principles of Electrical Machines provides a comprehensive and straightforward introduction to the principles, construction, operation, and applications of various electrical machines. It is well-regarded for its simple language, clear explanations, and a large number of solved examples and practice problems. The book is designed to help students build a strong foundation in the subject before they move on to more advanced topics.

Key Features and Content

Principles of Electrical Machines is typically structured into chapters that cover the main types of electrical machines and their related concepts. The contents generally include:

Part 1: DC Machines

This section provides the foundational knowledge of electromechanical energy conversion.

Chapter 1: Electro Magnetic Circuits: This introductory chapter sets the stage by covering the core concepts of magnetism. It explains magnetic fields, magnetic circuits, and compares them with electric circuits. It also introduces essential principles like magnetic hysteresis, hysteresis loss, and electromagnetic induction. This is a crucial foundation for understanding all electrical machines.
Chapter 2: DC Generators: This chapter dives into the construction and working principles of DC generators. It covers key topics such as armature reaction, commutation, and the various types of DC generators (series, shunt, and compound) along with their characteristic curves.
Chapter 3: Armature Reaction and Commutation: This is a more focused chapter that delves into two critical phenomena in DC machines: armature reaction (the effect of armature flux on the main field flux) and commutation (the process of reversing the current in the armature coils).
Chapter 4: DC Motors: This section covers the principles of DC motors, including their working principles, types, characteristics, and applications.
Chapter 5: Speed Control of DC Motors: This chapter is dedicated to the various methods used to control the speed of DC motors, which is a vital aspect of their application.
Chapter 6: Testing of DC Machines: The book explains the different methods used to test the performance of DC machines, such as the Swinburne's test, which helps in determining efficiency.

Part 2: Transformers

This part of the Principles of Electrical Machines book focuses on static electrical machines.

Chapter 7: Single-Phase Transformers: A detailed explanation of the construction, working principle, and phasor diagrams of single-phase transformers. Key topics include equivalent circuits, voltage regulation, and the different types of losses and efficiency calculations.
Chapter 8: Three-Phase Transformers: This chapter covers the construction and different connection methods for three-phase transformers (e.g., star-delta, delta-star). It also discusses the conditions for the parallel operation of three-phase transformers.

Part 3: AC Machines

This is a major portion of the book, covering all the primary types of AC machines.

Chapter 9: Three-Phase Induction Motors: This section introduces the construction, working principle, torque-speed characteristics, and various starting methods for three-phase induction motors.
Chapter 10: Circle Diagrams: This chapter explains the use of circle diagrams as a graphical method for analyzing the performance of induction motors.
Chapter 11: Single-Phase Motors: This chapter covers the principles and operation of single-phase motors, which are widely used in a variety of domestic and industrial applications. It discusses types like split-phase, capacitor-start, and shaded-pole motors.
Chapter 12: Alternators: This chapter deals with synchronous generators (alternators), covering their construction, excitation systems, voltage regulation, and the conditions for parallel operation.
Chapter 13: Synchronous Motors: The book explains the working principle, starting methods, and applications of synchronous motors. It also covers the concept of V-curves and their use in power factor correction.

Part 4: Special-Purpose Machines

Chapter 14: Special-Purpose Electric Machines: This chapter provides a brief introduction to machines not covered in the main sections, such as universal motors, stepper motors, servomotors, and linear induction motors.

Target Audience

This book is primarily aimed at:

Undergraduate engineering students pursuing degrees in Electrical, Electronics, and Instrumentation Engineering.
Diploma students in related fields.
Candidates preparing for competitive engineering examinations (e.g., AMIE) due to its clear explanations and extensive practice problems.

Strengths

Lucid and Simple Language: The book is known for its easy-to-understand style, which makes complex concepts accessible to beginners.
Comprehensive Coverage: It covers all the major topics related to electrical machines that are typically included in an undergraduate curriculum.
Problem-Solving Focus: The text includes a significant number of solved examples that illustrate the application of theoretical concepts, as well as chapter-end questions and multiple-choice questions for practice.
Clear Illustrations: The use of numerous figures and diagrams helps students visualize the construction and working principles of the machines.

In summary, "Principles of Electrical Machines" by V.K. Mehta is a classic and reliable choice for anyone looking for a foundational and practical understanding of the subject.