Electrical engineering is a field of engineering that in general deals with the study and application of electricity, electronics, and electromagnetism. Depending on how it is intended in different areas of the world, it may cover a wide range of subfields, including electronics, digital computers, power engineering, telecommunications, control systems, and signal processing.
This broad range of fields of interest can be split into two main areas:
- what we could call signal-oriented electrical engineering, for which electric
quantities (voltage, current, etc.) are used to carry signals—for example, inside
TV sets or computers or through electromagnetic waves;
- what we could call power-oriented electrical engineering, for which electric
quantities are used to manage and transfer power—for example, in power lines,
electric machines, rectifiers, or inverters.
Indeed, from a practical point of view, these two kinds of electrical engineering are very different from each other. The approach to analysing applications is different; the physical objects that fulfil different functions tend also to be very different. For instance, while the dimensions of signal-oriented electric devices have shrunk by several orders of magnitude in the last decades (think of computers or mobile phones, for instance), the dimensions of apparatuses tend to be much more stable whenever large powers are involved (e.g., the size of a 100 kW electric motor or a 100 MW power station has not changed significantly).
Electric power engineering is a branch of industrial engineering, while signal electrical engineering is generally not considered as such. University students of nonelectrical engineering, such as students of civil, mechanical, aerospace, chemical, or even control engineering, will be interested in power-oriented electrical engineering. Mechanical or aerospace engineers, for instance, should be able to understand in detail how an electric motor or an electric drive works. Civil engineers might need to understand how electrical installations are built and how the external power system feeding them operates. Basic information about the safety aspects of electricity might interest all of them.
This book aims to give university teachers support to teach nonelectrical engineering students all they need to know about basic electric phenomena, circuits, and electric machines and drives, as well as the basics of electric safety and an introduction to how large power systems are built and operated.
It might also be useful for professional engineers who want to have a source of updated, though concise, information of nearly everything that happens in poweroriented electrical engineering.
We have made every effort to explain each subject in the simplest way. However, in the case of more complex concepts, we have tried, rather than feigning simplicity, to illustrate them as clearly as possible. Taking our cue from Albert Einstein, we have adopted the approach of making everything as simple as possible, but not simpler.
This book tends to say things in a concise way. This is because we believe that this way it offers a stimulus to students: were we to describe each path of reasoning in detail, we would not stimulate the student’s independent flow of reasoning.