Basic Electrical Technology

Summary

Basic Electrical Technology is the most common subject and heart core subject to electrical engineers. 

Our life would be unthinkable without the use of electrical energy. The growing utilization of the latter is a decisive prerequisite for the rapid development of industry and agriculture.

A few examples will show the importance of electrical energy. Thus, electrical lighting is indispensable for working during the dark hours of the day. With increasing industrialization, a growing proportion of electrical energy is used for the lighting of shops, offices, dwellings and for outdoor lighting. Man is relieved from heavy physical labor by the use of electrical devices. The drive of machines, hoisting gear and lifts is enabled in a simple form by the electromotor which in railway transport also has the advantage over internal combustion engines. There are many buildings where an air-conditioning system including heating, cooling, and ventilation is installed for the operation of which electrical energy is required. At higher ambient temperatures, foodstuffs can only be kept for a prolonged period of time in refrigerators or cold-storage rooms which usually are also operated with electrical energy.

Without electrical energy, there would be no broadcasting and television systems, no telephone communication or telegraphy. In order to arrange automatic sequences of operation in production, devices of control a regulation engineering are required which, today, are driven almost exclusively by electrical energy. Table 1.1. shows a survey of the two large fields of electrical engineering, power electrical engineering, and information electrical engineering.

The consumption of electrical energy by the various branches of the economy is quite different. The chemical industry and metallurgy have a particularly high consumption. For the production of the electrical conductor materials electrolytic copper and aluminum, very large amounts of electrical energy are required.

Definitions

Basic Formulas Relating to Voltage, Current (Amps), & Resistance (Ohms or Ω ), Watts

Voltage = Current x Resistance

Current = Voltage / Resistance

Resistance = Voltage / Current

Watts = Volts x Amps

What is the definition of Alternating Current or AC

Alternating current is almost universally used for home electric power and is, therefore, the kind this article is primarily concerned with. In an AC circuit, the amount of voltage applied to the circuit is constantly changing from zero to a maximum and back to zero in one direction and then from zero to maximum and back to zero in the other direction. The maximum voltage is set by the generating plant.

Because voltage is the pressure that causes current to flow, the current will also change from zero to maximum to zero and will reverse direction and repeat. The maximum amount of current, however, is determined by the load resistance and can vary as the load resistance varies. Each complete change from zero to maximum to zero in one direction and then zero to maximum to zero in the opposite direction is called one hertz (formerly cycle).

The term hertz implies "per second." So, 60 hertz means the same as 60 cycles per second. Hertz is abbreviated Hz. Cycles-per-second, which you will still see marked in some electrical devices, is abbreviated cps.

What is the Definition of Direct Current or DC

Direct current is most commonly found in homes in the form of electrical energy stored in batteries. In a DC circuit, the amount of voltage and the direction of application are constant. The amount of voltage is determined by the type and size of battery. The direction of current flow is also constant and, as in AC circuits, the amount of current flow is determined by the load resistance.

Batteries convert chemical energy to electrical energy. The chemical energy can be in wet form, as in your car battery, or in dry form as in flashlight and transistor-radio batteries. Some batteries are designed to be recharged from an AC source. The voltage from all batteries, unless recharged, will gradually decrease. AC power can be converted to DC power for some uses in the home. The conversion is performed by a device called a rectifier or current converter.

Basic Electrical Technology Textbook to Refer: A Textbook of Electrical Technology in SI Units. Volume I: Basic Electrical Engineering By B.L.                                                                             Theraja and A.K. Theraja   CLICK HERE TO DOWNLOAD

BEE PDF NOTES-Short disciption form

Becoming an electrical engineer requires training, commitment, and the willingness to wonder about questions such as how a flat-screen television manages to be energy efficient or how a user manages to use so much electricity without blowing a fuse.

Electrical engineers answer the tough electrical questions and may work on anything from handheld gadgets to massive electrical grids. In getting there, electrical engineers must consider questions such as: What level of degree should I get to maximize my income? What concentration should I learn to obtain my dream career? Do I have to join an engineering firm or can I work on my own?

The subject aims to provide the student with, An understanding of basic Electrical Engineering abstractions on which analysis and design of electrical and electronic circuits and systems are based. The capability to use abstractions to analyze and design simple electric circuits. The ability to formulate and solve the differential equations describing the time behavior of circuits containing energy storage elements. An understanding of how complex devices such as semiconductor diodes and field-effect transistors are modeled and how the models are used in the design and analysis of useful circuits. The capability to design and construct circuits, take measurements of circuit behavior and performance, compare with predicted circuit models and explain discrepancies.

Unit - 1: DC Circuits

Unit - II: AC Circuits

Unit - III: Earthing & Lamps

Unit - IV: Three Phase AC Circuits

Unit - V: AC Machines

Unit - VI: Single Phase AC Motors

Basic Electrical Technology Lecturer NPTEL videos description notes by Prof. Dr.L. Umanand

Description About all chapters

I consider this as lecture 2 meaning the first part the motivation as 1, the second part the course contents as 2 and the lecture 3 which will be of course the next hour; all the lectures are 1 hour except for these parts 1 and 2 which does not have that 1 hour constrain. Lecture 3 that is lecture 3 will deal on the topic of the core topic of the electrical essential; it, of course, gives you an insight into what is the source and the load and how does the energy flow from the source to the load.

Lectures 4 and 5 again electrical essentials. We are going to discuss sources. what are the what are voltage sources what are current sources and in voltage and current sources what is the AC source, what is the DC source, what is the characteristic feature of the sources, how do you characterize them these are the topics that need to be covered and that will be covered in lecture 4 and 5.

Lecture 5 towards the end of it let us discuss two important laws which of course has come to be known as the Kirchhoff's voltage law and the Kirchhoff's current law

In lecture 6 in the electrical essentials, once you know how to deal with the analysis of the circuit in terms of the Kirchhoff's voltage law and the current law you should be you should know how to represent the electrical equipment electrical circuit in a mathematical form.

Lectures 7 and 8 of the electrical essentials will focus on the analysis of the mathematical model that has been developed in these three domains: in the time domain, in the frequency domain, and in the pole-zero domain.

Lecture 9 brings you the concepts of the phasor, the vector, the space-vector, space-phasor because in the analysis of the electrical circuits and especially when sinusoids are used the phasor diagram are used extensively to analyze or represent the circuits pictorially and therefore it is important to understand the concept of the phasor notation and what it means by a space phasor.

Lecture 10 and 11 of the electrical essentials we are talking of the same system which can be represented in the time domain, which can also be represented in the pole-zero domain and how we move about these domains, what is its significance in the other domains; these are issues that we will deal with.

And lecture 12 of the electrical essential describes the sinusoids. The sinusoidal wave shade, the sinusoidal waveform is a kind of a reference waveform for electrical engineers it is used it is kind of ubiquitous in almost all the electrical systems and it will appear as an input as an output, an intermediate waveform almost everywhere and a good understanding of the sinusoidal wave shape the various parameters its definitions, what is peak to peak, what is the RMS, what is an average and all those things should be properly understood and the sinusoid will be defined.

Then lecture 13 and 14 as I said, the electrical circuits and equipment have a graphical representation, also you have a mathematical representation find in the form of equations, you will also have a graphical representation in the form of phasor diagrams. So we will spend some time to understand what is this phasor analysis, how do we go about doing, given a circuit diagram how do we draw the phasor diagram and try to get meaning out of it.

Lecture 15 brings you the important concept of power factor. Power, when we draw from the source, has two components: the reactive power and the active power

And lecture 16 of the electrical essentials introduces to you the concept of ports the energy ports because you will be transiting from one domain one energy domain to another energy domain like the electrical domain to the magnetic domain to the mechanical domain.

Lecture 17, 18 now enters part II of our course pattern course lecture pattern which is the electromagnetic domain. First was electrical essentials that is over by chapter that is over by lecture 16. Lecture 17 starts with the electromagnetic domain, transformer, transformer basics, what are the essentials that are Faraday's laws of electro-magnetism what is it, how is the operation of the transformer so all those things will be discussed.

And then the equivalent and then the representation of the transformer in the electrical domain as circuit form, what is the phasor diagram all those things will be discussed in lectures 19 to 23. What is a practical transformer, what is an ideal transformer, what is the equivalent circuit of an ideal transformer and the practical transformer what are the differences and the various phasor diagrams will be the topic of focus in these lectures of 19 to 23 which is the electromagnetic domain?

Lectures 24 to 29 which is 24 25 26 27 28 29 you have the electro-magneto-mechanical domain. You see we are now entering the third part of the course pattern which is the machines. So here that is 24 to 29 we shall discuss the machine DC generator and the DC motor where the basics are to the understanding of all the machines.

Then we follow it up with lecture 30 to 35 lectures; again we are going to revisit transformers, again we are going to revisit the electro-magnetic domain that is the three-phase circuits and three-phase transformers. Till now we have been talking on a single phase but you will see the majority of the electrical systems operate on……… lot of electrical systems operate on three-phase and therefore you have three-phase circuits and three-phase transformer which will be dealt with detail in these lectures from 30 to 35.

And 36 to 39 we are again discussing the electro-magneto-mechanical domain which is the induction motor and the induction generator. The induction motor and induction generator are very important motors; they form something like 75 to 80 percent of the prime movers of the applications world over so they are quite important and a good understanding of these is useful both in application and design. So induction motors and induction generators. You see the induction generators will be used in the wind turbine generators, induction motors will be used in a lot of applications including the hybrid electric vehicles.

                                                              Lecture No.                       Download Link

Basic Electrical Technology ( Web Course)

Indian Institute of Technology Kharagpur

Kharagpur 721302, West Bengal.

Detailed Syllabus :

Module – 1 Introduction

Lesson – 1 Introducing the Course on Basic Electrical

Lesson – 2 Generation, Transmission and Distribution of Electric Power an Overview

Module – 2 DC Circuit

Lesson – 3 Introduction of Electric Circuit

Lesson – 4 Loop Analysis of the resistive circuit in the context of dc voltages and currents

Lesson – 5 Node-voltage analysis of resistive circuit in the context of dc voltages and currents

Lesson – 6 Wye (Y) - Delta (.) OR Delta (.)-Wye (Y) Transformations

Lesson – 7 Superposition Theorem in the context of dc voltage and current sources acting in a resistive network

Lesson – 8 Thevenin’s and Norton’s theorems in the context of dc voltage and current sources acting in a resistive network

Lesson – 9 Analysis of dc resistive network in the presence of one non-linear element

Module – 3 R-L & R-C Transients

Lesson – 10 Study of DC transients in R-L and R-C circuits

Lesson – 11 Study of DC transients in R-L-C Circuits

Module – 4 Single-phase AC Circuits

Lesson – 12 Generation of Sinusoidal Voltage Waveform (AC) and Some Fundamental Concepts

Lesson – 13 Representation of Sinusoidal Signal by a Phasor and Solution of Current in R-L-C Series Circuits

Lesson – 14 Solution of Current in R-L-C Series Circuits

Lesson – 15 Solution of Current in AC Series and Parallel Circuits

Lesson – 16 Solution of Current in AC Parallel and Series-parallel Circuits

Lesson – 17 Resonance in Series and Parallel Circuits

Module – 5 Three-phase AC Circuits

Lesson – 18 Three-phase Balanced Supply

Lesson – 19 Three-phase Delta-Connected Balanced Load

Lesson – 20 Measurement of Power in a Three-phase Circuit

Module – 6 Magnetic circuits and Core losses

Lesson – 21 Magnetic Circuits

Lesson – 22 Eddy Current & Hysteresis Loss

Module – 7 Transformer

Lesson – 23 Ideal Transformer

Lesson – 24 Practical Transformer

Lesson – 25 Testing, Efficiency & Regulation

Lesson – 26 Three Phase Transformer

Lesson – 27 Auto-Transformer

Lesson – 28 Problem solving on Transformers

Module – 8 Three-phase Induction Motor

Lesson – 29 Rotating Magnetic Field in Three-phase Induction Motor

Lesson – 30 Construction and Principle of Operation of IM

Lesson - 31 Equivalent Circuit and Power Flow Diagram of IM

Lesson – 32 Torque-Slip (speed) Characteristics of Induction Motor (IM)

Lesson – 33 Different Types of Starters for Induction Motor (IM)

Lesson – 34 Starting Methods for Single-phase Induction Motor

Module – 9 DC Machines

Lesson – 35 Constructional Features of D.C Machines

Lesson – 36 Principle of Operation of D.C Machines

Lesson – 37 EMF & Torque Equation

Lesson – 38 D.C Generators

Lesson – 39 D.C Motors

Lesson – 40 Losses, Efficiency and Testing of D.C. Machines

Lesson – 41 Problem Solving on D.C Machines

Module – 10 Measuring Instruments

Lesson – 42 Study of DC-AC Measuring Instruments

Lesson – 43 Study of Electro-Dynamic Type Instruments

Lesson – 44 Study of Single Phase Induction Type Energy Meter or Watt-hour Meter

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