ELEC4614 Power Electronics

Lecture 1 - Introduction 1-1 F. Rahman to power electronics

Lecture 1 - Introduction

The role of power electronics in electrical power utilization

Power Input

Controller

Input

Filter

Load

Electrical and mechanical variables

Power Output Output

Filter

Reference Inputs

Switching Converter

The reference inputs almost invariably have multiple objectives, such as input power factor, EMI containment, tight regulation of output voltage, current or frequency, output ripple or waveform quality, efficiency, protection and so on.

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-2 F. Rahman to power electronics

Linear VS switched-mode converter

B gsi or vΔ Δ

CE DSv or vΔ Δ

Vo

+Vref−

vdRLoad

AC Supply

Transformer

Diode Rectifier

Filter Voltage Regulator Load

vGS or iB

Controller

+ vDS or vCE −

Vdmax

Vdmin Vo

t

Vd range vd(t)

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-3 F. Rahman to power electronics

An example of switched mode converter:

V d

iLIL = I o

−V o voi

toff

vL V d - V o

0

0

t

t ton

V o

voi

Load

L Vo

Vd CD

T

Vsense

Controller

Isense

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-4 F. Rahman to power electronics

Applications of power electronic converter circuits

Residential Transportation

Refrigeration

Space heating

Air conditioning

Cooking

Lighting

Power supplies for consumer products

Computers

Electric trains, trams, vehicles

Battery chargers

Subways

Conveyor systems

Rapid transit systems

Commercial Utility Systems

Heating, ventilating, airconditioning

Refrigeration

Lighting

Computers & office equipment

Uninterruptible power supplies

Elevators

High-voltage DC-DC transmission

Static VAR compensation

Renewable energy sources (wind, PV, fuel cells)

Boiler feed systems

Energy storage

Industrial Aerospace

Pumps

Compressors

Blowers and fans

Machine tools

Arc and induction furnaces

Lighting

Welding

Process plants

Space vehicle power systems

Satellite power systems

Aircraft power systems

Aircraft controls

Telecommunications

Battery chargers

Power supplies

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-5 F. Rahman to power electronics

Types of converter circuits Broad classification (building blocks of more complex systems):

1. AC - DC (uncontrolled) *

2. AC - DC (controlled)

3. DC - DC (non isolated) *

4. DC - DC (isolated) *

5. DC – AC *

6. Hard switched & soft switched *

7. Resonant

8. AC-AC

* Converter circuits which will be covered in this course.

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-6 F. Rahman to power electronics

Commonly used converter circuits

The Step-down (Buck) converter and controller

Vo < Vd

********************************************

The Step-Up (Boost) converter

Vo > Vd

********************************************

Load

L Vo

Vd CD

T

Vsense

Controller

Isense

R (Load)

+

iD

+ vL −

iL

Vo CVd

ic

D

Io

id

T

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-7 F. Rahman to power electronics

D

C R L

T

Vd iL − Vo

+ Io id

iD

The Buck-Boost Converter

Vo > or < Vd

********************************************

R Vd

N1:N2 D

C

id

T

io

iT

v1

v2

Isolated Flyback (Buck-boost) converter

**********************************************

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-8 F. Rahman to power electronics

Vd

D1

D2

L iL N1 : N2

T

+ vL − C Vo Rv2

id

iT vT

v1

iD1Io

Isolated Forward (Buck) converter

********************************************

v1

Vd

N1

v2

T1 T2

R+ vL –

D2

N2D1 iL L

Vo

C voi v1s

v2s

N2N1

Isolated push-pull converter

********************************************

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-9 F. Rahman to power electronics

T1

T2

Vd Vd/2

+ v1

– N1

C1

C2

D1

D2

L

C R + voi

–

iD1 iL Io Vo

N2

N2+ vL −

Isolated Half-bridge converter

**********************************************

T1

T4

T3

T2

N1

+ −

Vd

Io

R+ vL –

Ds2

N2

Ds1 iL L

C voi v1s

v2sN2

v1

D1 D3

D4 D2

Vo

Isolated Full-bridge converter

**********************************************

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-10 F. Rahman to power electronics

Vd

RLAB

C

CT1

T2

D1

Half-bridge DC-AC single-phase inverter

**********************************************

Full-bridge DC-AC single-phase inverter

**********************************************

id

R L io A

T3

T2

D3

D2

B

+ vo −

T1

T4

D1

D4

Vd

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-11 F. Rahman to power electronics

Three-phase DC-AC inverter

**********************************************

Single-phase AC-DC rectifier circuits

**********************************************

D6T2 T4

T3T1 D3

D4

D1

Vd

D2

D5

T6

T5

CA B

A B C

ia ib ic 0V

+Vd/2

−Vd/2

id P

N

maxV sin tω

i2 D2

D1 i1

Vmax sinωtvs

ip R

L

iL

vo

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-12 F. Rahman to power electronics

Load R

L

Vd

vo

D1 D3 D5

D4 D6 D2

iL ia ib ic

van

vbn

vcn

n

Three-phase AC-DC rectifier circuit

**********************************************

3-phase AC

Supply Load

Vd

Id

Id /2

Id /2

Six-phase AC-DC rectifier

**********************************************

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-13 F. Rahman to power electronics

Single-phase boost rectifier for sinusoidal input current

**********************************************

D1 D3 D5

D4 D6 D2

ia ib ic

van

vbn

vcn

n

R

L

Vd

vo

iL

Three-phase AC-DC boost rectifier for sinusoidal input current.

***********************************************

maxV sin tω

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-14 F. Rahman to power electronics

Three-phase AC-DC boost rectifier with bi-directional

power flow

***********************************************

Diode-clamped multilevel inverter/rectifier (m = 5)

***********************************************

T4

T1

D4

D1

A

D6

T3D3

T6

B~ ~ ~ T2 D2

D5 T5

C Vd

3-phaseAC

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-15 F. Rahman to power electronics

Five-level capacitor-clamped multilevel converter

**********************************************

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-16 F. Rahman to power electronics

a cb

or etc.

SBcSBbSBa

SAcSAbSAa

SCcSCbSCa iC

iB

iA

icibia

A

B

C

=

A

B

C

a

c

b

iC

iB

iA

ic

ib

ia

SAc

SAb

SAa

SBc

SBb

SBa

SCc

SCb

SCa

(b)(a)

Three-phase to three-phase matrix converter

**********************************************

Single-phase AC-DC phase controlled rectifier.

**********************************************

Vd

ip

Vmaxsinωt

T1

T2T4

T3iL

vo

+

−

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-17 F. Rahman to power electronics

R

L

Vd

vo

T1 T3 T5

D4 D6 D2

iLia

ib

ic

van

vbn

vcn n

Three-phase AC-DC phase controlled rectifier.

**********************************************

3-phase AC

Supply

Vd

Id

Id /2

Id /2

Six-phase AC-DC phase controlled rectifier.

**********************************************

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-18 F. Rahman to power electronics

Single- and multi-stage power converters

Single-stage conversion

Two-stage conversion

Converter AC/DC Input from

Utility

AC/DC Output

to Load

Converter 1

AC/DC from

Utility

AC/DC Output to Load

Converter2 C

Control circuits

Control circuits

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-19 F. Rahman to power electronics

Examples

Grid

100V 340V

PVArray

Boost Converter

Single-phase inverter

PV inverter systems

**********************************************

A BC A B C

Generator

Grid

Rectifier/Inverter

IndGen

Converter for wind energy systems

**********************************************

ELEC4614 Power Electronics

Lecture 1 - Introduction 1-20 F. Rahman to power electronics

Automobile traction drive systems

**********************************************