In addition to a brief introduction to the historical development of electric motors and considerations of electrotechnical and physical fundamentals, this paper contains a comparison of internal combustion engines and electric motors. Furthermore, requirements and operating modes of electric motors are explained. In the center of the work are treatments of selected electric motors in relation to structure, mode of operation and power range. The work ends with a conclusion in which the advantages and disadvantages of the motor types mentioned and further developments are considered.
Electric motors have a major role to play in terms of potential savings in electricity consumption. Without sufficient measures, it is assumed that worldwide electricity consumption by means of electric motors will almost double by 2030.
Electric motors are responsible for about 40 percent of total electricity consumption worldwide and for about 70 percent of the electricity consumed by industry.
In Germany, electricity consumption by electric motors is about 55 percent, in industry the share is 68 percent, the tertiary sector has a share of 48 percent and the share of private households reaches a level of 41 percent. About 96 percent of the electric motors sold in Europe are used by means of single-phase or polyphase alternating current, and for this reason they are the focus of the observations made in Chapter 7.
The author points out with reference to the limited extent of the work to be provided in connection with the complexity of the topic, which is renounced in particular on the derivation, the bare denomination and the generalization of formulas and formula components.
Table of Contents
1 Foreword
2 Historical development
3 Physical and electrotechnical basics
4 Comparison of combustion engine/ electric motor
5 Requirements for an electric motor in the automobile
5.1 Resistance to oil
5.2 Resistance to water
6 Operating modes of an electric motor
6.1 Engine operation
6.2 Generator operation
7 Structure and operation of electric motors
7.1 General
7.2 DC motor
7.2.1 Structure and mode of action of a DC motor
7.2.2 Power range of the DC motor
7.3 AC motor (1-phase AC)
7.3.1 AC synchronous motor
7.3.2 AC asynchronous motor
7.4 Three-phase motor (3-phase alternating current)
7.4.1 Three-phase synchronous motor
7.4.1.1 Structure and mode of action of a three-phase synchronous motor
7.4.1.2 Power range of the three-phase synchronous motor
7.4.2 Three-phase asynchronous motor
7.4.2.1 Structure and mode of action of a three-phase asynchronous motor
7.4.2.2 Power range of the three-phase asynchronous motor
7.4.3 Reluctance motor
7.5 Linear motor
8 Conclusion
Objectives and Topics
This work aims to provide a comprehensive overview of the historical development, physical principles, and operational requirements of various electric motor types used in modern automotive applications, ultimately evaluating their suitability and performance characteristics.
- Historical context and evolution of the electric motor
- Fundamental electrotechnical and physical principles
- Comparative analysis of internal combustion engines versus electric motors
- Operational modes including engine and generator functionalities
- Structural and performance evaluation of DC, AC, three-phase, and linear motors
Excerpt from the book
2 Historical development
If one considers the historical development of the electric motor, one must preface this further fundamental development steps.
In 1800, the Italian Allexandro Volta produced for the first time a continuously flowing electric current, from a stack of zinc and silver plates. The Dane Hans Christian Oersted recognized in 1820 by observing the deflection of a conventional compass needle the generation of magnetic fields by means of electric currents. Oersted is thus considered to be the one who caused mechanical movement for the first time by electric current. In the same year, the Frenchman André-Marie Ampére invented the cylinder coil. Based on the findings of Ampére, the Englishman William Sturgeon developed the first functional electromagnet in 1825, which consisted of an iron core for field amplification. This laid the foundations for the construction of electric motors.
It should be noted, however, that even before Sturgeon, his compatriot Peter Barlow in 1822 designed the first device driven and rotating by electromagnetism, the Barlow's wheel named after him. Furthermore, it should not be forgotten that Michael Faraday and Joseph Henry created further electrotechnical foundations with the discovery and research of electromagnetic induction. Also to be mentioned must be Hippolyte Pixii, who in 1832 created the first rotary apparatus for the generation of alternating current.
Summary of Chapters
1 Foreword: This chapter highlights the critical role of electric motors in electricity consumption and outlines the scope, motivation, and structure of the present work.
2 Historical development: This section details the key scientific breakthroughs from Volta's current to Jacobi's first rotating electric motor, tracing the early origins of electrotechnology.
3 Physical and electrotechnical basics: This chapter explains the essential physical laws, such as Faraday's law, Maxwell's equations, and Lorentz force, that govern electric motor operation.
4 Comparison of combustion engine/ electric motor: This section presents a comparative analysis of maintenance, efficiency, environmental impact, and mechanical characteristics between combustion engines and electric motors.
5 Requirements for an electric motor in the automobile: This chapter addresses the harsh environmental challenges, specifically oil and water resistance, required for integrating electric motors into automotive powertrains.
6 Operating modes of an electric motor: This section discusses the dual roles of electric machines as both motors and generators, including the principles of regenerative braking.
7 Structure and operation of electric motors: This core chapter provides technical classifications and detailed structural analyses of DC, AC, three-phase, and linear electric motors.
8 Conclusion: The final chapter summarizes the advantages and drawbacks of different motor types and comments on future development trends and energy efficiency regulations.
Keywords
Electric Motor, Electromagnetism, Induction Law, Combustion Engine, Hybrid Vehicles, DC Motor, AC Motor, Three-phase Motor, Rotor, Stator, Energy Efficiency, Regenerative Braking, Reluctance Motor, Frequency Converter, Power Density.
Frequently Asked Questions
What is the core focus of this publication?
The work provides a comprehensive technical overview of electric motors, covering their history, physical fundamentals, operational requirements, and a detailed classification of different motor types.
Which motor types are the primary focus?
The publication analyzes DC motors, AC motors (1-phase), and particularly emphasizes three-phase motors (synchronous and asynchronous) due to their industrial and automotive significance.
What is the main objective regarding automotive applications?
The primary objective is to evaluate how different electric motors meet automotive requirements, such as power density, operational noise, maintenance, and environmental protection.
What scientific methodology is utilized?
The work employs a literature-based comparative analysis, synthesizing theoretical physical foundations with historical context and contemporary technological standards.
What topics are covered in the main body of the text?
The main body examines electricity consumption, comparative performance metrics against combustion engines, technical design constraints like oil/water resistance, and the structural differences between various electric machines.
How is this work characterized?
It is characterized by its systematic approach to motor classification, focus on automotive integration, and integration of energy efficiency standards.
What is the significance of the "three-finger rule" mentioned in the text?
It is used as a mnemonic to determine the spatial relationship between magnetic field direction, current direction, and the resulting movement or Lorentz force direction.
What are the critical challenges for electric motors in hybrid vehicles?
Key challenges include limited installation space, the need for high power density, thermal management, and protection against environmental factors like oil and saline water.
Why is the "three-phase asynchronous motor with short-circuit rotor" widely used?
It is cited as the most commonly used motor type due to its extreme robustness, simple design, low maintenance needs, and reliability.
What is the role of the frequency converter in synchronous motor performance?
Frequency converters are essential for enabling control over the stator rotary field, which in turn allows for precise regulation of the engine speed.
- Arbeit zitieren
- Michael Gräbner (Autor:in), 2015, Electric motors. History, structure, mode of operation and power range, München, GRIN Verlag, https://www.grin.com/document/1358850
