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24 Νοε 2013 (πριν από 3 χρόνια και 4 μήνες)

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©Copyright Ned Mohan 2008
1
First Course on
Power Electronics
Module 1: Introduction
Reference Textbook:
First Course on Power Electronics by Ned Mohan,
www.mnpere.com
By
Ned Mohan
Professor of ECE
University of Minnesota
©Copyright Ned Mohan 2008
2
Chapter 1 Power Electronics: An Enabling Technology
1-1 Introduction to Power Electronics
1-2 Applications and the Role of Power Electronics
1-3 Energy and the Environment
1-4 Need for High Efficiency and High Power Density
1-5 Structure of Power Electronics Interface
1-6 Voltage-Link Structure
1-7 Recent and Potential Advancements
References
Problems
Module 1: Introduction to Power
Electronics
©Copyright Ned Mohan 2008
3
Role of Power Electronics
Figure 1-1 Power electronics interface between the source and the load.
Converter
Controller
SourceLoad
Power Electronics
Interface
Converter
Controller
SourceLoad
Power Electronics
Interface
The power electronics interface facilitates the transfer of power from the source to the
load by convertin
g
volta
g
es and currents from one form to another, in which it is possible
for the source and load to reverse roles. The controller shown in Fig. 1-1 allows
management of the power transfer process in which the conversion of voltages and
currents should be achieved with as high energy-efficiency and high power density as
p
ossible.

©Copyright Ned Mohan 2008
4
Powering the Information Technology
Figure 1-2 Regulated low-voltage dc power supplies.
Power
Converter
Controller
o
V
,oref
V
in
V
Utility
24 V (dc)
5 V (dc)
3.3 V (dc) 0.5 V (dc)
(a)(b)
Power
Converter
Controller
o
V
,oref
V
in
V
Power
Converter
Controller
o
V
,oref
V
in
V
Utility
24 V (dc)
5 V (dc)
3.3 V (dc) 0.5 V (dc)
Utility
24 V (dc)
5 V (dc)
3.3 V (dc) 0.5 V (dc)
(a)(b)
©Copyright Ned Mohan 2008
5
Boost Converter
Figure 1-3 Boost dc-dc converter needed in cell operated equipment.
BatteryCell (1.5 V)
9 V (dc)
BatteryCell (1.5 V)
9 V (dc)
©Copyright Ned Mohan 2008
6
Adjustable Speed Drives
Figure 1-4 Block diagram of adjustable speed drives.
Power
Processing
Unit (PPU)
fixed
form
measured
speed/ position
speed /
position
Motor
Electric
Drive
Load
input command
(speed / position)
Power
Signal
adjustable
form
Electric Source
(utility)
Sensors
Controller
©Copyright Ned Mohan 2008
7
Induction Heating
Figure 1-5 Power electronics interface required for induction heating.
High
Frequency
AC
Power
Electronics
Interface
Utility
High
Frequency
AC
Power
Electronics
Interface
Utility
©Copyright Ned Mohan 2008
8
Electric Welding
Figure 1-6 Power electronics interface required for electric welding.
DC
Power
Electronics
Interface
Utility
DC
Power
Electronics
Interface
Utility
©Copyright Ned Mohan 2008
9
Energy and the Environment: The Percentage
Energy Consumption
Figure 1-7 Percentage use of electricity in various sectors in the U.S.
Motors 51%HVAC 16%
IT
14%
Lighting 19%
Motors 51%HVAC 16%
IT
14%
Lighting 19%
Motors 51%HVAC 16%
IT
14%
Lighting 19%
©Copyright Ned Mohan 2008
10
Figure 1-8 Role of adjustable speed drives in pump-driven systems.
Adjustable
Speed Drive
(ASD)
Inlet
Outlet
Pump
utility
Adjustable
Speed Drive
(ASD)
Inlet
Outlet
Pump
utility
Role of adjustable speed drives in
pump-driven systems
©Copyright Ned Mohan 2008
11
Compact Fluorescent Lamps
Figure 1-9 Power electronics interface required for CFL.
CFL
Power
Electronics
Interface
Utility
CFL
Power
Electronics
Interface
Utility
©Copyright Ned Mohan 2008
12
•Hybrid electric vehicles with much higher gas mileage
•light rail, fly-by-wire planes
•all-electric ships
•drive-by-wire automobiles.
Transportation
Figure 1-10 Hybrid electric vehicles with much higher gas mileage.
©Copyright Ned Mohan 2008
13
Renewable Energy
Photovoltaic Systems
Figure 1-11 Photovoltaic Systems.
(a)
Power
Electronics
Interface
Utility
DC Input
(b)
(a)
Power
Electronics
Interface
Utility
DC Input
(b)
Power
Electronics
Interface
Utility
DC Input
Power
Electronics
Interface
Utility
DC Input
(b)
©Copyright Ned Mohan 2008
14
Wind-Electric Systems
Figure 1-12 Wind-electric systems.
Utility
Generator
andPower Electronics
Utility
Generator
andPower Electronics
Utility
Generator
andPower Electronics
©Copyright Ned Mohan 2008
15
Uninterruptible Power Supplies
Figure 1-13 Uninterruptible power supply (UPS) system.
Utility
CriticalLoad
Uninterruptible
Power Supply
Utility
CriticalLoad
Uninterruptible
Power Supply
©Copyright Ned Mohan 2008
16
Applications in Power
Systems
©Copyright Ned Mohan 2008
17
Strategic Space and Defense Applications
Electric Warship
More Electric Aircraft
Source: James Soeder, NASA and Terry Ericsen, ONR.
©Copyright Ned Mohan 2008
18
NEED FOR HIGH EFFICIENCY AND
HIGH POWER DENSITY
o
oloss
P
PP
η
=
+
1
oloss
PP
η
η
=

Figure 1-14 Power output capability as a function of efficiency.
in
P
o
P
loss
P
()a
Power
Electronics
Equipment
0.8
0.82
0.84
0.86
0.88
0.9
0.92
0.94
0.96
0
50
100
150
200
250
300
350
400
450
500
Efficiency
Power Rating
()b
o
P
20
loss
PW=
10
loss
PW=
η
in
P
o
P
loss
P
()a
Power
Electronics
Equipment
0.8
0.82
0.84
0.86
0.88
0.9
0.92
0.94
0.96
0
50
100
150
200
250
300
350
400
450
500
Efficiency
Power Rating
()b
o
P
20
loss
PW=
10
loss
PW=
η
©Copyright Ned Mohan 2008
19
Summarizing the Role of Power Electronics
Output to Load
-Adjustable DC
-Sinusoidal AC
-High-frequency AC
utility
Power
Electronics
Interface
Output to Load
-Adjustable DC
-Sinusoidal AC
-High-frequency AC
utility
Power
Electronics
Interface
Figure 1-15 Block diagram of power electronic interface.
Output to Load
-Adjustable DC
-Sinusoidal AC
-High-frequency AC
utility
Power
Electronics
Interface
Output to Load
-Adjustable DC
-Sinusoidal AC
-High-frequency AC
utility
Power
Electronics
Interface
Figure 1-15 Block diagram of power electronic interface.
©Copyright Ned Mohan 2008
20
STRUCTURE OF
POWER
ELECTRONICS INTERFACE
Voltage-link structure of power electronics interface
•Unipolarvoltage handling transistors used
•Decoupling of two converters
•Immunity from momentary power interruptions
Figure 1-16 Voltage-link structure of power electronics interface.
conv1conv2
controller
utilityLoad
conv1conv2
controller
utilityLoad
©Copyright Ned Mohan 2008
21
•Current-Link Systems
•Matrix Converters
©Copyright Ned Mohan 2008
22
Figure 1-17 Current-link structure of power electronics interface.
AC1AC2
AC1AC2
AC1AC2AC1AC2
Current-Link Systems
©Copyright Ned Mohan 2008
23
Figure 1-18 Matrix converter structure of power electronics interface [13].
vC
vB
vA
vc
vb
va
ia
daA
dbA
dcA
daB
daC
dbB
dbC
dcB
dcC
vC
vB
vA
vc
vb
va
ia
daA
dbA
dcA
daB
daC
dbB
dbC
dcB
dcC
Matrix Converters
©Copyright Ned Mohan 2008
24
Figure 1-19 Load-side converter in a voltage-source structure.
conv1conv2
controller
utilityLoad
conv1conv2
controller
utilityLoad
Voltage-link System
©Copyright Ned Mohan 2008
25
SWITCH-MODE LOAD-SIDE CONVERTER
• Group 1
Adjustable dc or a low-frequency sinusoidal ac output in
- dc and ac motor drives
- uninterruptible power supplies
- regulated dc power supplies without electrical isolation
• Group 2
High-frequency ac in
- compact fluorescent lamps
- induction heating
- re
g
ulated dc power supplies where the dc output volta
g
e needs to be
electrically isolated from the input, and the load-side converte
r

internally produces high-frequenc
y
ac, which is passed throu
g
h a
high-frequency transformer and then rectified into dc.
©Copyright Ned Mohan 2008
26
Switch-Mode Conversion: Switching Power-Pole
as the Building Block
Figure 1-20 Switching power-pole as the building block in converters.
(b)
A
v
0
t
in
V
+
-
(a)
+
-
A
v
A
q
(b)
A
v
0
t
(b)
A
v
0
t
in
V
+
-
(a)
+
-
A
v
A
q
in
V
+
-
(a)
+
-
A
v
A
q
in
V
A
v
0
1
A
q=
(b)
A
v
0
t
in
V
+
-
(a)
+
-
A
v
A
q
(b)
A
v
0
t
(b)
A
v
0
t
in
V
+
-
(a)
+
-
A
v
A
q
in
V
+
-
(a)
+
-
A
v
A
q
in
V
A
v
0
(b)
A
v
0
t
in
V
+
-
(a)
+
-
A
v
A
q
(b)
A
v
0
t
(b)
A
v
0
t
in
V
+
-
(a)
+
-
A
v
A
q
in
V
+
-
(a)
+
-
A
v
A
q
in
V
A
v
0
1
A
q=
©Copyright Ned Mohan 2008
27
Pulse-Width Modulation (PWM) of the Switching Power-Pole
up
A
inAin
s
T
vVdV
T
==
01
A
d


(/)
A
ups
dTT
=
Figure 1-21 PWM of the switching power-pole.
(a)
(b)
A
v
in
V
+
-
+
-
A
i
1or0
A
q=
As
dT
dA
i
up
T
s
T
A
q
A
v
0
0
t
t
1
in
V
A
v
A
v
in
V
+
-
+
-
A
i
1or0
A
q=
As
dT
dA
i
up
T
s
T
A
q
A
v
0
0
t
t
1
in
V
A
v
(a)
(b)
A
v
in
V
+
-
+
-
A
i
1or0
A
q=
As
dT
dA
i
up
T
s
T
A
q
A
v
0
0
t
t
1
in
V
A
v
A
v
in
V
+
-
+
-
A
i
1or0
A
q=
As
dT
dA
i
up
T
s
T
A
q
A
v
0
0
t
t
1
in
V
A
v
A
d
(a)
(b)
A
v
in
V
+
-
+
-
A
i
1or0
A
q=
As
dT
dA
i
up
T
s
T
A
q
A
v
0
0
t
t
1
in
V
A
v
A
v
in
V
+
-
+
-
A
i
1or0
A
q=
As
dT
dA
i
up
T
s
T
A
q
A
v
0
0
t
t
1
in
V
A
v
(a)
(b)
A
v
in
V
+
-
+
-
A
i
1or0
A
q=
As
dT
dA
i
up
T
s
T
A
q
A
v
0
0
t
t
1
in
V
A
v
A
v
in
V
+
-
+
-
A
i
1or0
A
q=
As
dT
dA
i
up
T
s
T
A
q
A
v
0
0
t
t
1
in
V
A
v
A
d
©Copyright Ned Mohan 2008
28
Switching Power-Pole in a Buck DC-DC Converter:
An Example
oAAin
VvdV==
0
oin
VV


Figure 1-22 Switching power-pole in a Buck converter.
in
V
+

A
q
+

A
v
+

o
V
in
i
L
i
As
dT
s
T
A
q
A
v
L
i
in
i
0
0
0
0
t
in
V
t
t
t
1
(a)
(b)
in
V
+

A
q
+

A
v
+

o
V
in
i
L
i
in
V
+

A
q
+

A
v
+

o
V
in
i
L
i
As
dT
s
T
A
q
A
v
L
i
in
i
0
0
0
0
t
in
V
t
t
t
1
As
dT
s
T
A
q
A
v
L
i
in
i
0
0
0
0
t
in
V
t
t
t
1
(a)
(b)
A
v
in
V
+

A
q
+

A
v
+

o
V
in
i
L
i
As
dT
s
T
A
q
A
v
L
i
in
i
0
0
0
0
t
in
V
t
t
t
1
(a)
(b)
in
V
+

A
q
+

A
v
+

o
V
in
i
L
i
in
V
+

A
q
+

A
v
+

o
V
in
i
L
i
As
dT
s
T
A
q
A
v
L
i
in
i
0
0
0
0
t
in
V
t
t
t
1
As
dT
s
T
A
q
A
v
L
i
in
i
0
0
0
0
t
in
V
t
t
t
1
(a)
(b)
A
v
©Copyright Ned Mohan 2008
29
Figure 1-23 Waveforms in the converter of Example 1-2.
A
q A
v
20
in
VV=
12
o
VV=
0
1
3s
μ
5s
μ
t
t
0
A
q A
v
20
in
VV=
12
o
VV=
0
1
3s
μ
5s
μ
t
t
A
q A
v
20
in
VV=
12
o
VV=
0
1
3s
μ
5s
μ
t
t
0
Example 1-2 In the converter of Fig. 1-22a, the input voltage
20
in
VV=
. The
output voltage
12
o
VV=
. Calculate the duty-ratio
A
d
and the pulse
width
up
T, if the switching frequency
200
s
fkHz=
.
Solution
12
Ao
vVV==
. Using Eq. 1-4,
12
0.6
20
o
A
in
V
d
V
=== and
1
5
s
s
Ts
f
μ
==.
Therefore, as shown in Fig. 1-23, 0.653
upAs
TdTss
μμ
==×=.
©Copyright Ned Mohan 2008
30
Simulations usin
g

PSpice
SwitchingWaveform.Sch
©Copyright Ned Mohan 2008
31
Simulation Results

Time
450us
460us
470us
480us
490us
500us
V(vA)
V(vo)
0V
2.0V
4.0V
6.0V
8.0V
A
v
oo
vV

©Copyright Ned Mohan 2008
32
Fourier Analysis
FOURIER COMPONENTS OF TRANSIENT RESPONSE V(vA)

DC COMPONENT = 6.080000E+00

HARMONIC FREQUENCY FOURIER NORMALIZED PHASE
N
ORMALIZED
NO (HZ) COMPONENT COMPONENT (DEG) PHASE (DEG)

1 1.000E+05 3.487E+00 1.000E+00 -4.860E+01 0.000E+00
2 2.000E+05 2.543E+00 7.293E-01 -7.200E+00 9.000E+01
3 3.000E+05 1.310E+00 3.757E-01 3.420E+01 1.800E+02
4 4.000E+05 1.600E-01 4.589E-02 7.560E+01 2.700E+02
5 5.000E+05 6.012E-01 1.724E-01 -6.300E+01 1.800E+02
6 6.000E+05 8.387E-01 2.405E-01 -2.160E+01 2.700E+02
7 7.000E+05 6.193E-01 1.776E-01 1.980E+01 3.600E+02
8 8.000E+05 1.600E-01 4.589E-02 6.120E+01 4.500E+02
9 9.000E+05 2.763E-01 7.923E-02 -7.740E+01 3.600E+02
10 1.000E+06 4.924E-01 1.412E-01 -3.600E+01 4.500E+02
©Copyright Ned Mohan 2008
33
FOURIER COMPONENTS OF TRANSIENT RESPONSE V(vo)

DC COMPONENT = 6.083044E+00

HARMONIC FREQUENCY FOURIER NORMALIZED PHASE
N
ORMALIZED
NO (HZ) COMPONENT COMPONENT (DEG) PHASE (DEG)

1 1.000E+05 1.795E-02 1.000E+00 1.343E+02 0.000E+00
2 2.000E+05 3.400E-03 1.894E-01 1.746E+02 -9.403E+01
3 3.000E+05 8.465E-04 4.715E-02 -1.489E+02 -5.518E+02
4 4.000E+05 1.226E-04 6.826E-03 -1.492E+02 -6.865E+02
5 5.000E+05 1.602E-04 8.922E-03 1.447E+02 -5.269E+02
6 6.000E+05 1.718E-04 9.570E-03 1.707E+02 -6.352E+02
7 7.000E+05 1.158E-04 6.448E-03 -1.626E+02 -1.103E+03
8 8.000E+05 5.644E-05 3.143E-03 -1.560E+02 -1.231E+03
9 9.000E+05 4.483E-05 2.497E-03 1.751E+02 -1.034E+03
10 1.000E+06 5.570E-05 3.102E-03 1.789E+02 -1.164E+03
©Copyright Ned Mohan 2008
34
Currents

Time
450us
455us
460us
465us
470us
475us
480us
485us
490us
495us
500us
I(L)
I(C)
I(R)
0A
10A
-4A
16A
R
i
L
i
C
i
©Copyright Ned Mohan 2008
35
Frequency Analysis
SwitchingWaveform_AC-Analysis.Sch
©Copyright Ned Mohan 2008
36
Simulation Results

Frequency
100Hz
1.0KHz
10KHz
100KHz
1.0MHz
DB(V(vo)/V(VA))
-100
-50
0
50
(100.000K,-45.867)
©Copyright Ned Mohan 2008
37
Transistor and diode forming a switching power-pole
in a Buck converter
Figure 1-24 Transistor and diode forming a switching power-pole in a Buck converter.
(b)
(c)
(a)
in
V

+
L
i
L
i
L
i
1
A
q=0
A
q=
+

o
V
+

o
V
+

o
V
in
V

+
in
V

+
(b)
(c)
(c)
(a)
in
V

+
L
i
L
i
L
i
1
A
q=0
A
q=
+

o
V
+

o
V
+

o
V
in
V

+
in
V

+
©Copyright Ned Mohan 2008
38
Hardware Lab: ver
y
low-cost
Switching Power-Pole Board
Magnetics Plug-In Board
Feedback Control Plug-In Board
Experiments:
-
Buck, Boost, Buck-Boost
-
Feedback Control: Voltage-
Mode, Peak-Current-Mode
-
Flyback, Forward
USERS MANUAL
www.ece.umn.edu/groups/power
©Copyright Ned Mohan 2008
39
RECENT AND POTENTIAL ADVANCEMENTS
•Devices that can handle voltages in kVsand currents in kAs
•ASICs
•DSPs
•Micro-controllers
•FPGA
•Integrated and intelligent power modules
•Packaging
•SiC-based solid-state devices
•High energy density capacitors
©Copyright Ned Mohan 2008
40
CONCEPT OF PEBB
It has numerous benefits such as technology insertion and upgrade via
standard interfaces, reduced maintenance via plug and play modules,
reduced cost via increased product development efficiency, reduced time to
market, reduced commissioning cost, reduced design and development risk,
and increased competition in critical technologies [14].
Power Electronics Building Block (PEBB) [15] is a broad concept that
incorporates the progressive integration of power devices, gate drives,
and other components into building blocks, with clearly defined
functionality that provides interface capabilities able to servemultiple
applications. This building block approach results in reduced cost,
losses, weight, size, and engineering effort for the applicationand
maintenance of power electronics systems. Based on the functional
specifications of PEBB and the performance requirements of the
intended applications, the PEBB designer addresses the details of
device stresses, stray inductances, switching speed, losses, thermal
management, protection, measurements of required variables, control
interfaces, and potential integration issues at all levels.
©Copyright Ned Mohan 2008
41
Summary

Power Electronics an Enabling
Technology

Applications

Need for High Efficiency and High Power
Density

Structure of Power Electronic Converters

Switching Power-Pole as the Building
Block

Potential for Advancements