SPEEDAM 2008

International Symposium on Power Electronics,

Electrical Drives, Automation and Motion

Interinstitutional Activity in Professional

Training in Power Electronics
V. Vodovozov, D. Vinnikov, J. Laugis, and T. Lehtla
Tallinn University of Technology, Department of Electrical Drives and Power Electronics
Ehitajate tee 5, 19086 Tallinn, Estonia

Abstract-- Novel interinstitutional activities in power Master’s degree (MSc) is awarded after deeper study,
electronics education and specialists training are proposed. commonly involving some course oriented toward design
Some valuable results concerning methods, research, and and research in power electronics applications with
experimental work carried out by Tallinn University of prospective work on a doctoral thesis or a graduation
Technology and St. Petersburg Electrotechnical University project. Close attention in this study is paid to
are presented. The paper is focused on the inter-disciplinary
understanding the performance of components and
curriculum, the virtual e-learning electronic laboratory, the
versatile approach to the course and diploma design, and subsystems, mathematical simulation, and laboratory
the first experience in team design organization. An open experiments. Next, PhD training is oriented on in-depth
access to the developed educational resources is provided research in new directions of science. Post-graduate
via the Internet. courses (PG) are aimed toward knowledge improvement
in the field. To assemble the disciplines most relevant to
Index Terms-- interinstitutional activity, interdisciplinary power electronics education, a list of interinstitutional
curriculum, virtual e-learning electronic laboratory, power activities has been proposed. Focus is on:
electronics. • development of methods in the field;
• course design and sufficient curricular
I. INTRODUCTION arrangement;
In power electronics most beneficial technological • experimental teaching and learning involving the
innovations have been introduced into processes and analysis and updating procedures.
energy distribution. In numerous industrial and vehicular
applications, the assemblies of mechanically and II. THEORY AND SIMULATION IN TEACHING POWER
electrically coupled devices are joined in electronic units ELECTRONICS
of high complexity. Such systems provide control,
TABLE I
management, and monitoring that cover a broad range of THE AREAS OF THE INTERINSTITUTIONAL COLLABORATION
tasks. This is the reason of increased attention shown
towards specialists teaching and professional training in Simulation toolboxes
Level Discipline
the area, mainly in the most recent developments in ETU TUT
Fundamentals of
component technologies, converter topologies, system MatLab MathCAD
Electrical Engineering
decoupling, and dynamic performance with invariance to Microprocessors MultiSim
disturbances and robustness against the parameter Control Theory LabView MatLab
variation. Information
St. Petersburg Electrotechnical University (ETU), C++ C++
Technologies
BSc
Russia, and Tallinn University of Technology (TUT), Electrical Machines and
eDrive MatLab
Estonia, have built an effective tandem, the mission of Motor Drives
which is to find a solution to some primary educational Fundamentals of
problems in this sphere. In the joint project, TUT as a Electronics
host institution has provided its classes and laboratories Fundamentals of Power
Electronics Area of collaboration
for the experiment, whereas a visiting professor from
Power Electronic
ETU has delivered lectures, exercises, tests, and Converters of Motor
examinations in accordance with the program agreed. Drives
The spectrum of the key directions of power Control Automatic LabView
electronics studies is determined by the curricula that MSc System Modeling and
Simulink
bear sufficient similarities in the universities of both Simulation
countries, Russia and Estonia, covering four traditional Adjustable Motor Drives eDrive Simulink
levels. To obtain the first Bachelor’s degree (BSc), Electronic Controllers Omron Simatec
knowledge of basic electronics must be acquired. This toolbox toolbox
BSc study is oriented on the common understanding of PhD Research and
development in the field Area of collaboration
today’s engineering in the “physical sense”. A higher
PG Knowledge Improvement
This work was supported by Estonian Foundation for Lifelong
Learning Development INNOVE (Project IN7061).

978-1-4244-1664-6/08/$25.00 ©2008 IEEE

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 The list of topics hereunder holds the headlines of the power electronics circuits, calculation and selection of
typical environment of the power electronics disciplines, power electronic components, topological schematic
proposed as the result of the joint curriculum [1]. The design and circuit diagrams building, efficiency
areas of the institutional collaboration are particularly evaluation and measuring with waveform analysis,
picked out in Table 1. explanation, and documentation of the obtained results.
They are arranged on the models of dc and ac voltage
III. PRACTICE IN MULTISIM and current sources; voltage-controlled, current-
Simulation in Multisim enables a clear analysis of all controlled, pulse and clock sources; resistors,
electronic circuits, simple parameters variation in a broad potentiometers, capacitors, inductors; different switches;
range, and favorable possibilities in result evaluation with diodes, full-wave bridge rectifiers, silicon-controlled
virtual measurements. Computer simulators provide rectifiers; BJTs and 3-terminal enhancement n-
reading of results, their processing, and comparison. MOSFETs; opamps; virtual measuring devices; buck,
boost and buck-boost converters; oscilloscopes and
Multisim libraries are well suited for electronics needs,
function generators. The list of experiments developed
providing different complexity levels of passive
for the course includes:
components, amplifiers, and switches, from ideal to
• single-phase half-wave rectifiers (M1-rectifier
precision dynamic models. Its built-in tools enable data
with resistive and inductive loads and LC filters built on a
processing, magnetic design, frequency analysis, and
diode and a thyristor);
what is really important, interfacing with other simulation
instruments, such as Spice, Simulink, and LabView. • single-phase full-wave rectifiers (mid-point M2-
The first section of the developed virtual e-learning rectifiers and bridge B2-rectifiers with resistive and
laboratory is meant for the course “Fundamentals of inductive loads and LC filters built on diodes and
Electronics” in the BSc study. Practice includes a set of thyristors);
exercises in electronics, the tasks of which is to introduce • three-phase rectifiers (mid-point M3-rectifiers and
electronic circuits research and calculation, selection of bridge B6-rectifiers built on diodes and thyristors);
electronic components, virtual schematic building, virtual • ac converters (single-phase voltage regulator and
voltage and current measurements and waveform bridge inverter, voltage source and current source
analysis, results explanation, and documentation. inverters as well as the different frequency converters);
For circuit assembling, the learners use the models of • choppers (step-down choppers, closed-loop buck
dc and ac voltage sources, a current-controlled voltage converter, step-up choppers, closed-loop boost converter,
source, resistors and potentiometers, capacitors and step-down and step-up choppers, closed-loop buck-boost
inductors, diodes, transistors, 3-terminal opamps, converters, and Cuk regulators).
comparators, oscilloscopes, function generators, Bode As a result, students compare the calculated and
plotters, and multimeters. The list of experiments experimental data and prepare reports with experimental
developed for the course includes: circuit diagrams, resulting and comparative data tables,
• linear circuits (RL, RC, RLC, series, and parallel voltage and current traces, dependency diagrams, and
resonant circuits); conclusions with explanations.
• passive filters (RC and LC LPF and HPF, band- The scope of experimental works seems more
pass, and band-stop filters); comprehensive, complex, and different from that
described in literature [5][6][7]. It takes advantage of
• diode circuits (plotting the output diagrams of
covering the whole spectrum of problems in power
single diodes, series and parallel clippers, limiters, and
electronics studied in electrical engineering and
different Zener circuits); electronics departments of technical universities [8].
• amplifiers (plotting input and output Moreover, the listed works distributed between the
characteristics of CE, CB, and CC amplifiers); disciplines are united by the common idea and a uniform
• opamps (non-inverting and inverting voltage methodical approach.
amplifiers, detectors built on comparators, and Schmitt
trigger); IV. RESEARCH AND DESIGN WITH eDRIVE
• math converters (summer, subtracter, integrator,
The integrated toolbox eDrive has been chosen as the
differentiator, and PID-regulator);
educational design core of the industrial units with
• oscillators (astable multivibrators and Wien bridge electronic components. The package contains instruments
oscillators with unipolar and balanced supply). for the development and investigation of electric drives
At the end of each exercise, students compare the with electronic converters. Thanks to its strong
calculated data and the outputs of virtual experiments and orientation to the driving applications, this software
generate a report with an experimental circuit diagram, offers some advantages to power users and students over
resulting and comparative data tables, voltage and current other programs.
traces, dependency diagrams, and conclusions with For equipment computation, the leading companies
explanations. have developed their specific technologies. Examples are
The second section of the developed e-learning library the guides and software of “Siemens”, “Omron”, “Sew
is oriented to the course “Power Electronics” of the BSc Eurodrive”, “Maxon Motors”, “Mitsubishi”, etc. In these
study. Practice involves a set of experiments in power packages, the automatic checking of the preliminary
electronics, the tasks of which cover the development of worked-out databases accomplishes the search of the

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decision. With the help of the corporative databases, • the signal generator for supplying the test
some combinations of parameters may be chosen and reference and loading signals as well as non-linear
optimized from a particular criteria point of view. A curves, noses, and filters imitation;
scope of allowable environment condition is displayed in • the report generator with powerful graphic multi-
a certain data area. System tuning is executed in format support.
accordance with the corporative methods also. A classification of the supplies processed by the
Such an approach is conventional for the majority of software and stored in eDrive database is given in Fig. 1.
firms that carry out project designs and have rich A generalized discrete converter description is proposed
experience in the acceptance of the decisions on the basis on the basis of the power converter models of different
of extensive computer databases, coming up to numerous types. Transistor and thyristor converters of different
catalogue archives and “absorbing” their contents and kinds are considered as the particular cases and the
structures. However, the main drawback is the inheritors of the selected model. Such approach helps to
technological restriction and limitation of data that
develop a system in accordance with the technique
deprive a designer of an optimum way in the project. It is
renovations. Besides the data sheets, a user may work
especially important in the first design stage, when the
with queries written in the standard SQL language, which
most responsible decisions are taken.
In distinct from the companies, which promote and serves as another source of the model information.
propagate their products, the eDrive approach is POWER
addressed to the full equipment selection, tuning, and SOURCES
optimization independently on the firm interests. The
program eDrive is available for:
• simulation of power electronics systems and SUPPLY FROM
SUPPLY FROM
components of driving industrial applications; THE MAINS ELECTRONIC
• selection of converters, motors, and gears in the CONVERTERS
process of system design;
• analysis of steady-state and transient modes of
applications with open-end and closed-loop control Transistor Thyristor
systems supplied from the mains and power converters; based converters based converters
• research of options, disturbances, and input signals
impact on the system performance;
• system tuning; ac/dc dc/dc ac/dc
(rectifiers) (choppers) (rectifiers)
• generation of reports about the system
arrangement and operation.
The eDrive software is a real example of the object- ac/ac
dc/ac ac/ac
(dc link and
oriented technology implementation [9][10]. It supports (inverters) (cycloconverters)
matrix converters)
the uniform and versatile approach to the objects of
different nature: mechanical, electrical, and Fig. 1. Classes of supplies processed by eDrive
informational, undoubtedly required by a power
electronic system. Its generalized objects description In the design process, a learner generates numerous test
gives an effective tool for the model base classes design, signals destined to:
which applies an inheritance of new modules without any
• enter various references and disturbances to the
deconstruction of the main model structure. The
simulated applications;
developed class library comes up to ANSI standards and
contains the components, fully described in the scientific • examine the influence of distortions and
and educational literature [11] as well as in the toolbox disturbances upon the behavior of the components;
documentation. The software demonstrates a clear and • select filters and correcting circuits for designed
user-friendly performance for those who have decided to systems, which improve their performance.
learn about the applications with electronic converters For the last purpose eDrive includes:
and get an experience in project development in a cost- • the group Signal that represents numerous sources
and time-effective manner. of references and disturbances;
The package includes numerous simulation tools: • the group Distorsion that brings distortions of any
• a set of adjustable controller schemes; kind to the transmission path of a signal selected in
• models of industrial converters, gears, and previous group;
regulators; • the group Filter/Corrector that simulates a digital
• the equipment databases of the world leading conversion of a signal selected in a previous group in
companies; accordance with the proposed transfer function;
• the graphic package for representation of steady- • the chart of output signals of all mentioned
state and dynamic simulated processes with automatic groups.
and manual scaling, system analyzer, and preview
facilities; Moreover, a designer may utilize the simulation result
as a new signal. The program receives an output trace for

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its further processing and analysis. All these units are http://www.edrive.narod.ru. From the same site, links are
available as variants of a common transfer function, supplied to the databases of the leading world electronic
which simulates the same amplifiers, filters, and circuits and drive companies. The first printed materials appeared
that were studied earlier with Multisim. Such in the University libraries in 2006 .
interconnection of the toolboxes is a significant
advantage of the described approach. Another benefit REFERENCES
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