Table Of ContentTallinn University of Technology
Department of Electrical Drives and Power Electronics
ELECTRONIC
SYSTEMS
OF
MOTOR
DRIVE
Valery Vodovozov
Dmitri Vinnikov
Tallinn
2008
Authors Valery Vodovozov, Dmitri Vinnikov
Edited by Mare-Anne Laane
Reviewed by Ivars Rankis, Dr.Hab.Sc.Ing., Professor of Riga Technical University
Cover design by Ann Gornischeff
Preparation and publication of this book was supported by SA Innove
Tallinn University of Technology
Department of Electrical Drives and Power Electronics
Ehitajate tee 5, Tallinn 19086
Phone 620 3700
Fax 620 3701
http://www.ene.ttu.ee/elektriajamid/
Copyright: Valery Vodovozov, Dmitri Vinnikov, Tallinn University of Technology,
Department of Electrical Drives and Power Electronics, 2008
ISBN .............................
Publisher: TUT, Dept. of Electrical Drives and Power Electronics
3
Contents
Designations....................................................................................................................5
Symbols....................................................................................................................................5
Abbreviations............................................................................................................................6
Introduction......................................................................................................................7
1. Motor Supplies...........................................................................................................13
1.1. AC/DC Converters – Rectifiers........................................................................................13
1.2. DC/AC Converters – Inverters.........................................................................................23
1.3. AC/AC Converters – Changers.......................................................................................34
1.4. DC/DC Converters – Choppers.......................................................................................43
2. Power System Engineering.......................................................................................55
2.1. Design Objective.............................................................................................................55
2.2. Transformers and Inductors............................................................................................61
2.3. Diodes and Thyristors.....................................................................................................66
2.4. Transistors.......................................................................................................................69
2.5. Accidental Protection.......................................................................................................76
2.6. Braking............................................................................................................................82
2.7. Filters...............................................................................................................................85
3. Gating of Power Switches..........................................................................................92
3.1. Thyristor Gate Circuits.....................................................................................................92
3.2. Transistor Gate Circuits.................................................................................................102
3.3. Block Modulation...........................................................................................................121
3.4. Pulse-Width Modulation................................................................................................130
3.5. Space Vector Modulation..............................................................................................137
4. Control Engineering.................................................................................................142
4.1. Transfer Functions and Block Diagrams.......................................................................142
4.2. Signal Converters and Controllers................................................................................145
4.3. Controller Design...........................................................................................................151
4.4. Motor Control.................................................................................................................158
5. Motor Drive Engineering..........................................................................................166
5.1. Electrical Motor..............................................................................................................166
5.2. Scalar Control of the Induction Motor............................................................................171
5.3. Vector Control of Induction Motor..................................................................................178
5.4. Synchronous Servo Drives............................................................................................188
5.5. DC Motor Drives............................................................................................................192
6. Application Examples..............................................................................................198
6.1. Design of Motor Drives Fed by Industrial Mains............................................................199
6.2. Design of Motor Drives with Battery Supply..................................................................211
6.3. Design of Boost Converter for Motor Supply.................................................................218
6.4. Design of Two-Switch Trasformer-Isolated Forward Converter for Motor Supply.........223
Appendixes. Specifications of Wiring Diagrams..........................................................233
Appendix 1. Servo Drive of Mitsubishi Electric.....................................................................233
Appendix 2. Asynchronous Drive of Sew Eurodrive.............................................................233
Appendix 3. DC Drive BTU 3601..........................................................................................234
Appendix 4. Asynchronous Drive.........................................................................................235
Appendix 5. DC Drive...........................................................................................................235
4
Further Reading.......................................................................................................... 236
Monographs..........................................................................................................................236
Dictionaries...........................................................................................................................241
References on Simulation Instruments.................................................................................241
List of Journals......................................................................................................................242
Useful Links................................................................................................................ 244
Electronic Converters and Motor Drive Manufacturers.........................................................244
Driver and Component Manufacturers..................................................................................244
Index........................................................................................................................... 245
5
Designations
Symbols
A amplifier R resistance
B sensor r radius
С capacitor S slip
D digital device s differential operator
G generator T period, time constant
L inductor, choke t time
M motor U voltage
R resistor v velocity
S switch X reactance
T transformer x,y arbitrary axes frame
VD diode z arbitrary variable
VS thyristor Z impedance
VT transistor W energy
Z load W(s) transfer function
A area w number of turns
a acceleration α firing angle
B flux density α,β stator axes frame
C capacitance β angle in advance
cos φ power factor γ overlap angle
d,q rotor axes frame δ error
F force η efficiency
f frequency
θ electrical angle
I current
λ overshoot
i gear ratio
μ friction
J moment of inertia
ν velocity
k factor, coefficient
ς path, length
L inductance
π circle ratio (3,14159)
L1,2,3 three-phase frame
σ leakage factor
M torque
m phase number, mass Φ constant flux
n rotational frequency τ temperature
P power φ angle
p number of poles ψ flux linkage
Q charge ω angular frequency
q duty cycle
6
Abbreviations
A Ampere M Mega = 106 (prefix)
ac alternating current m milli = 10-3 (prefix)
ASIPM application specific IPM MCT MOS-controlled thyristor
BJT bipolar junction transistor MLT mean number of turns
CFC current-frequency control MMF magnetomotive force
CSI current source inverter MO module optimum setting
dc direct current MOS metal-oxide semiconductor
DSP digital signal processor n nano = 10-9 (prefix)
DTC direct torque control p pico = 10-12 (prefix)
EMC electromagnetic compatibility PDU pulse distribution unit
EMF electromotive force PWM pulse-width modulation
EO exponential optimum setting rms root mean square
ESL equivalent series inductance rpm revolution per minute
ESR equivalent series resistance s second
F Farad SCR silicon controlled rectifier
FET field-effect transistor SO symmetrical optimum setting
FOC field-oriented control SVM space vector modulation
G Giga = 109 (prefix) V Volt
GTO gate turn-off thyristor VDC dc Volt
H Henry VFC voltage-frequency control
Hz Hertz VSI voltage source inverter
IGBT insulated gate bipolar transistor W Watt
IPM intelligent power module ZCS zero-current switch
JFET junction FET ZVS zero-voltage switch
k kilo = 103 (prefix) μ micro = 10-6 (prefix)
LPF low-pass filter Ω Ohm
7
Introduction
“Be careful in driving!”
Charlie Chaplin
Electronics and motor drives make up a large part of
engineering and have close connections with almost all areas of
physics, chemistry, and mechanics. They establish a rapidly
expanding field in electrical engineering and a scope of their
technology covers a wide spectrum. Optimists envision
electromechanics doing more and more things for the population.
Electric appliances contribute to a healthier and more comfortable
live the worldover. Electronic communications spread fast,
allowing an ever-greater exchange of facts, opinions, and
cultures. Electrical machines with electronic converters do a lot of
difficult work for us. Thanks to advances in science and related
technology, many people no longer have to spend almost all of
their time working for the bare necessities of life. Whatever it is
that we really want to do, electronics and motor drive help us to
do it better.
Historical background. In terms of world history both electronics and motor drives are
young sciences. Less than three centuries have passed since their first ideas appeared among
the researchers.
The conviction that the world and everything in it consists of matter in motion drove scientists to
research the models for electronics and mechanics intersection. It was inconceivable to many
people that one body could directly affect another across empty space. They devised a variety
of schemes to explain of how one body exerts a force of another.
Isaac Newton (1643…1727) assumed that the bodies can act through empty space. The
profoundly important ideas of field existence were introduced into physics by Michael Faraday
(1791…1867). Early in the nineteenth century, he stated the general principle of
electromagnetic induction – changing lines of magnetic force can induce a current. Then, Georg
Simon Ohm (1787…1854) found the relation between the current and voltage called Ohm’s law.
The first concrete evidence of a connection between electricity and magnetism came in 1820,
when Hans Christian Oersted (1777…1851) discovered that a magnetic field surrounds an
electric current and further Andre-Maria Ampere (1775…1836) described the mutual magnetic
force between the circuits carrying currents. In the 1860s James Clark Maxwell (1831…1879)
developed a mathematical theory of electromagnetism. Thus, he predicted the existence of
electromagnetic waves as interrelating electric and magnetic fields that change together, much
like the “action” and “reaction” of Newton’s third law. Moreover, he argued that light actually
does consist of electromagnetic waves and that waves exert a pressure on any surface that
reflects or absorbs them.
8
These facts marked the effective start of the electric power age and became the roots of
electrical engineering established on three basic principles: 1. An electric current in a conductor
produces a magnetic force that circles around the conductor. 2. When a conductor moves
across external magnetic lines of force, a current is induced in the conductor. 3. A changing
electric field produces a magnetic field and vice versa.
The growth of the electrical industry has resulted largely from the great public demand for
electrical products. In 1879, Thomas Alva Edison (1847…1931) developed a practical light bulb
and began a search for a suitable non-metallic substance for the current flow. Later, Heinrich
Hertz (1857…1894) and Peter Lebedev (1866…1912) approved these ideas that prepared a
rapid bloom of new technologies, such as radio, television, computers, etc.
The first electrical motors built by Joseph Henry (1797…1878) in 1831 and Moritz Hermann
Jacobi (1801…1874) in 1834 were utilized immediately. In 1886 electric variable speed drive
represented by Ward Leonard system was born. In 1889 the squirrel-cage induction motor was
invented by Michail von Dolivo-Dobrowolsky (1862…1919). Next, in 1890 the speed control of
the slip-ring induction motor drive was suggested.
At the end of the 19th century, the first mercury arc vacuum valve as well as the arc valve and
the mercury rectifier were invented. Then, the vacuum diode appeared and the vacuum tube
and a vacuum triode were patented. Next, many types of electronic devices were worked out. In
1923, ignitron-made controlled rectification became possible. Further, in 1928 the thyratron and
grid controlled mercury arc rectifiers were invented. The first power inverter was born in 1930.
A phenomenon of semiconductance was discovered as far back as 1882, and this effect was
proposed for rectifying alternating current instead of mechanical switches. The real era of
semiconductor devices began in 1947, when John Bardeen, Walter Brattain, and
William Shockley invented a germanium transistor that was awarded the Nobel. In 1950s, the
silicon-based power switches were applied for the first time and manufacturing of the first
germanium diodes started. During the middle of the 1950s through to the early 1960s, electronic
circuit designs began to migrate from vacuum tubes to transistors, thereby opening up many
new possibilities in research and development projects. The first silicon transistors gained a
wide commercial acceptance because of the increased temperature performance and reliability.
The invention of the integrated circuit in 1958 was followed by the planar process in 1959 that
became the key of solid-state electronics.
Before the 1960s, semiconductor engineering was regarded as part of low-current and low-
voltage electronic engineering. In 1970 one of the most exciting decades in the history of low-
current electronics began. The 1980s are featured as high growth years for integrated circuits,
hybrid, and modular data converters. The major applications in the 1990s were industrial
process control, measurement, instrumentation, medicine, audio, video, and computers. In
addition, communications became an even bigger driving force for low-cost, low-power, high-
performance converters in modems, cell phones, wireless infrastructure, and other portable
applications. The trends of more highly integrated functions and power dissipation drop have
continued into the 2000s.
The period of power semiconductors started in 1950s, when the silicon thyristors were invented.
Based on these inventions, several generations of power devices have been worked out. The
years 1956…1975 can be considered as the era of the first power components generation.
During the second generation from 1975 until 1990, the metal-oxide semiconductor field-effect
9
transistors, bipolar transistors, junction transistors, and gate turn-off thyristors were developed.
Later the microprocessor drivers, specified integral circuits, and power integral circuits were
produced. In the 1990s, the insulated gate bipolar transistor was established as the power
switch of the third generation.
A new trend in electronics arrived with the use of intelligent power devices and intelligent power
modules. In the middle of the 1990s, universal drives (a general-purpose open-loop vector
drive, a closed-loop flux vector drive, a direct torque controlled drive, and a servo drive)
supplemented industry applications. Some time later, pulse-width modulated drives became a
commercial product.
Electronic systems. Electronic systems are applied in all branches of industry as well
as in domestic equipment. Power supply units, electric heaters, lighting systems, energy supply
plants, as well as electric drives are all widespread examples of power electronic systems.
Converters having electronic control feed an increasing number of drives. This permits adjusting
the operating point of a motor, i. e. speed, torque, and consequently energy consumption.
A power electronic converter is a part of an electronic system, which transforms electrical
energy supplying the loads. Depending on the voltage and power rating, they are used with
either single-phase or three-phase mains. It is also of significance whether the amplitude of
voltage from the alternating current (ac) mains supply is to be varied or whether a variable direct
current (dc) is to be generated. The common basic factor is that the form of electrical energy is
converted and adjusted. In doing so, it is important that as dependent on the requirement,
energy is consumed from the supply via the converter, or that energy can be fed back into the
mains supply.
Control electronics provides the control of the converters and electronic systems. Successes in
the fields of electronics and materials production determine the situation and trends in the world
of drive technology.
Each electronic converter consists of the primary electronic components that are resistors,
capacitors, transformers, inductors (choke coils), etc., and basic classes of semiconductor
devices:
• diodes, including Zener, optoelectronic and Schottky diodes, and diacs;
• thyristors, particularly silicon-controlled rectifiers (SCR), triacs, gate turn-off
(GTO), and MOS-controlled thyristors (MCT);
• transistors, such as bipolar junction (BJT), field-effect (FET), and insulated
gate bipolar (IGBT) switches.
Applications of electronics are still expanding thanks to improvements in semiconductor
technology, which offer higher voltage and current rating as well as better switching
characteristics. On the other hand, the main advantages of modern electronic converters such
as high efficiency, low weight and small dimensions, fast operation and high power densities are
gained using the switch-mode operation, in which semiconductor devices are controlled on
on/off fashion.
Motor drives. Motor drives form an extremely important application area of electronics
with a market value of tens of billions euros annually. An electric drive or motor drive is an
assembly of an electronic system, an electrical motor, and mechanical transmission joined to
drive a mechanical load by electrical energy. Schematics of typical drives are diverse. Fig. I.1
shows a generalized block diagram of a motor drive. Its upper part represents the drive power
10
U U
sup load
Power Load
M
Mains converter
Controls
Gate
circuit
Feedbacks
from
References
sensors
Inputs
Controller
Fig. I.1
system whereas the lower part is the control system. In response to an input command, dc and
ac drives efficiently control the speed, torque, and position of the mechanical load. By
comparing the input command for speed, torque, or position with the actual values measured
through sensors, the controller provides appropriate reference signals to the gate circuit, which
controls the power converter. As Fig. I.1 shows, the power converter is powered from the utility
source with single-phase or three-phase sinusoidal voltages of a fixed frequency and constant
amplitude and converts them into an output of the appropriate form (in frequency, amplitude,
and the number of phases) that is optimally suited for operating the motor.
In many general-purpose applications, electric drives operate in an open-loop manner without
any feedback. This large group of simple drive systems with energy supply by mains is used in
a variety of industrial and domestic machines. Different power converters can be found in drive
systems with a battery supply such as forklift trucks, starter generators, and automotive auxiliary
drives. The converters can feed dc motors, ac asynchronous (induction), and synchronous
machines.
An electrical motor represents a specific load of a power electronic converter, which model
constitutes a composition of three components (Fig. I.2): resistance, inductance, and counter-
electromotive force (back EMF). Moreover, usually these components change in values during
the system operation. Motor resistance depends on the temperature, inductance varies with the
rotor position replacement, and EMF is a function of the rotor speed.
Being a specific converter load, motor does not typically operate at constant speed. Often its
intermittent duty includes rapid acceleration and deceleration in both directions, in addition to
M
R L EMF
Fig. I.2
