lesson 1 - introduction to power electronics

8/13/2019 Lesson 1 - Introduction to Power Electronics

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1

Introduction to

Power Electronics


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Course Outline

I. Introduction

II. Power Electronics Devices

III. Typical Waveforms

IV. Power ConversionA. AC-DC

B. DC-DC

C. DC-AC

D. AC-AC


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Reference Books

I. Power Electronics: Circuits, Devices &

Application- M.H. Rashid; Prentice Hall of India. 3rd edition,2004

II. Power Electronics, Applications & Design

Ned Mohan; John Wiley & Sons. 3rd edition, 2002

III. Power Electronics

Cyrill Lander; Mc Graw Hills Co., 3rd edition, 1993.

IV. Modern Power Electronics & AC Drives

B.K. Bose; Pearson Education Inc., 2002

V. Switching Power Supply Design 3rd Edition

- Pressman, Billings, Morey, 2009


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Power electronics is the technology associated with

efficient conversion and control of electric power using

semiconductor devices.

Power electronic converters are devices that modify theform of electrical energy (i.e. change its voltage, current or

frequency).

The power range of these converters is from somemilliwatts (as in a mobile phone) to hundreds of megawatts

(e.g. in a HVDC transmission system).

I. Introduction


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Why Power Electronics?

Smaller Size. Less Weight.

Higher Efficiency.


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Power conversion is responsible for majority of theefficiency loss in an electronic device.

Why is Efficiency so criticalin Power Electronics?


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How can a power conversion

device be efficient?

Avoid lossy resistive elements as much aspossible.

Avoid operating in linear region when

semiconductor devices.

Use elements that does not consume power

such as Inductors (L) and Capacitors (C).

Operate semiconductor devices in cutoff and

saturation region.


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Switching Converters

Due to the need to operate thesemiconductor devices in either saturation

or cut-off region. The power electronicsdevices must be in switched modeoperation.

Power Converters operating in switchedoperation are also called switch-modeconverters.


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Applications

Power Supplies ( AC and DC) Lighting

Motor Drives

Induction Heating

Electric Welding

Solar / Wind etc. Power Conversion HV Power Transmission


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Diodes SCRs

Triacs

BJTs Mosfets

II. Power Electronics Devices


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Introduction to

Semiconductor Materials

1s2 2s2 2p6 3s2 3p2


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Introduction to

Semiconductor Materials


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Diode Characteristic


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Transistor


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Semiconductor Switch When SW is OFF; I=0A

When SW is ON; I=IA

SOA


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AC/DC converters (rectifiers)

- converts the mains AC to DC output.

- used on almost all electronic devices that is plugged in the AC sockets

like computers, TVs etc.).

DC/DC converters

- converts DC input to another DC output level.

- Used on car chargers/adaptors.

AC/AC converters

- converts AC to another forms of AC where the AC voltage level or

frequency is changed.

- used as frequency converters. In power distribution networks AC/AC

converters may be used to exchange power between 50 Hz and 60 Hz powergrids.

DC/AC converters

- used to convert DC input to any form of AC output.

- commonly used on inverters as computer back up sources.

Types of Power Converters


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Linear Converters


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References http://en.wikipedia.org/wiki/Power_electronics

http://www.youtube.com


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END

lesson 1 - introduction to power electronics

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