power electronics lec 1

7/30/2019 Power Electronics Lec 1

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Power ElectronicsMUHAMMAD NAVEED IQBALG.C UNIVERSITY LAHORE


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Introduction

Basic course of electrical engineering

Very important and interesting

Easier to understand but involve lots of mathematics

You must have a good knowledge of KVL, KCL and behaviinductors and capacitors

Prerequisites: Circuit theory, Semiconductor devices

Involves control theory, digital and analogue electronics,microprocessor and microcontrollers


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Course Information

Credits: This is a 3+1 credit course

Expected workload is 10 -12 hours per week throughoutweek session.

Contact hours: The course consists of 3 hours of lecturesand 3 hour of lab work per week:

Students are encouraged to use the open consultation hcontact by email.

Monday: 10:00AM 12:00PM

Friday 08:00 AM 10:00 AM


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Assessment

Laboratory work, reports, projects 50 Marks (60% duringand 40% in final exam)

You must at least score 50% to pass.


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Books

Muhammad H. Rashid, Power Electronics: Circuits, DeviApplications, Third Edition, 2004, Prentice Hall, ISBN: 01

N. Mohan, T. M. Undeland & W. P. Robins, Power ElectrConverters, Applications and Design, John Wiley, Second1995, New York.


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Week Lecture C

Week 1 Introduction to power electronics

Solid-state devices used in power electronics

Week 2 The Power Diode

Thyristors

Week 3 GTO Thyristors A

Power Bipolar Transistors,

Week 4 The Power MOSFET

Insulated Gate Bipolar Transistor, TRIAC, DIAC

Week 5 Quiz 1 A

Diode RectifiersWeek 6 Single-Phase Controlled Rectifiers

Three-Phase Controlled Rectifiers

Week 7 Twelve-pulse and Twenty-four pulse rectifiers;

DC to DC conversation, buck converter

Week 8 boost converter, buck-boost converters

Isolated converters, forward converters


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Week Lecture C

Week 9 Flyback converters

Quiz 2 [Mid Term]

Week 10 Single-Phase Voltage Source Inverters, 3-Phase Voltage Source Inverters

pulse-width-modulated (PWM) inverters

Week 11 Resonant Switch

Quasi-Resonant Converters

Week 12 Zero voltage switch

Three-phase inverters

Week 13 Single-Phase AC -AC Voltage Controller, 3-Phase AC-AC Voltage Controllers

Quiz 3 AWeek 14 Cyclo-converters

DC=DC Conversion, Positive Ouput Luo-Converters

Week 15 Negative Ouput Luo-Converters

Double Output Luo-Converters

Week 16 Revision

Revision


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Power Electronics

Whats it all about

How can you control power?

Power + Electronics


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Introduction

Power electronics today is one of the most important resareas of electrical engineering

Power electronics devices are almost every where

Thats why very important course.

Modern computers, communication and electronic systtheir blood from power electronics

Solid state electronics brought the first electronics revowhereas solid state power electronics brought the seconelectronics revolution


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How power electronics works


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Energy Challenges

Globally more than 85% energy comes from fossil fuel

6% nuclear

Remaining from renewables

We have limited reserves of fossil fuels and projections are thmore than 100-150 years

Nuclear 50 years

Oil 50 years

Coal 150 years

Natural gas 200 Years


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Energy Challenges

Some problems associated with nuclear thermal power p

Waste handling

Plant safety issues

GHG emission from thermal power plants

Global warming

Every year mount Everest losing 10cm height

Polar caps melting 15% faster now (2007 study)

Solution is to cut down emission of green house gasses


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Solution

Efficiency

Changing living style

Designing energy efficient equipment

Energy efficient architecture

Renewables

Finding new ways to produce energy Improvement of existing techniques


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Efficiency Improvements


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How power electronics can help

Improvement of existing power supplies and power man

Explore the new ways to improve efficiency

With the help of power electronics, it is possible to extrafrom renewables


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Power electronics and Efficiency

Bulk power used by motors mostly

Induction motor driving loads (compressor, pumps)

Lighting is another major usage of electricity


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Water Pump

Lets suppose we connect induction motor to a pump

Motor has a constant speed

Thrust proportional to square of speed

T 2

P 3

Now we need to decrease the flow of water and this can be dvalve

This is practice has poor energy efficiency

Is there any way to increase efficiency here.


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Speed Control

If we can somehow reduce the speed of induction moto

increase efficiency

Lets suppose we have reduced speed to half

Power will decreased 8 times

Its a remarkable way to reduce energy consumption

What will be the effect if all induction motors have this c


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Speed Control

Using power electronics we can achieve high efficiency a

frequency converter is our answer here

Frequency decreases than speed decreases

Life of machine increases and stress decreases

What happen when we start a motor directly from powe

Large current, stress on cables and windings

Anyone know a motor speed control drive?


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Celling Fan regulators

We can reduced our fan speed by using regulators

Old regulators were using resistors

or transformers.

Bulky, heat loss limited control


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New regulators

Light weight less heat dissipation logger life

Use semiconductor devices

Better control


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Smart grids

power electronics lec 1

Documents