LEA

 

Elektrische Bahnantriebe (f. Elektrotechniker u. Maschinenbauer)

In this lecture, Prof. Müller-Hellmann will talk about recent developments in the field of mass transit systems (MTS). Here, questions of technology as well as questions of management are discussed. The legal framework for the technology, the operation and the financing of MTS are comprehensively explained. Urban transport systems and vehicles such as trams, urban, underground, suburban trains and novel driverless systems are presented in the lecture. Basic considerations such as daily peaks of transportation and the highest possible utilization of the trains are explained and solution concepts discussed. In addition, issues of energy supply and safety aspects of electric transport systems are presented. An excursion to a local transport company completes the lecture.

For further information on the lecture: Campus

 

Power Electronics - Control, Synthesis and Applications (CSA)

Power Electronics generally have the goal to perform electrical energy conversion at high efficiency. The course focuses on the following aspects of converter design:

  • Minimum converter losses
  • silicon and magnetics losses
  • thermal design
  • Soft switching of silicon devices to improve device ratings
  • Using snubbers
  • Soft-switching converter topologies
  • Galvanically isolated dc-dc converters
  • Transformers in power electronics, using uni- and bidirectional core excitation
  • AC-AC converters
  • Control of voltage source converters
  • High-power electronics
  • Examples

For further information on the lecture/exercise class: Campus

For further information on the revision course: Campus

Further information on the laboratory exercise class will be announced in the lecture or alternatively in the L2P-learning room.

 

Power Electronics - Fundamentals, Topologies and Analysis (FTA)

Power electronics deals with control and efficient conversion of electric energy by means of power-electronic switches. Areas of application are e.g. automotive electric propulsion and power systems, distributed generation using wind turbines, solar converters or fuel cells, battery systems, industrial drives and induction heaters, as well as utility-scale power flow control and DC transmission systems. The course first presents modes of operation and topologies of line- and self-commutated converters. Line-commutated converters, switching at the frequency of the connected single or three-phase system, are introduced discussing important applications such as two-way rectifiers and cycloconverters. A separate section is dedicated to harmonic distortion. Self-commutated converters such as DC/DC topologies and voltage or current source inverters are analyzed, with a special focus on various control concepts, e.g. current control and pulse-width modulation (PWM). A manuscript is available. The lecture is held in English.

For further information on the lecture/exercise class: Campus

For further information on the revision course: Campus

For further information on the laboratory exercise class: Campus

 

Power Semiconductor Devices

  • Basics of semiconductor physics: Production process of silicon, Zone melting for n-doped silicon, Doping processes, Repetition of the basic equations on carrier transport and generation
  • PN junction: Structure, Thermal equilibrium, Schottkys parabola approximation, Field and diffusion currents, Boltzmann equation, Diffusion voltage, Space charge zone, Behavior at low-level injection, Blocking operation, Performance and blocking capability
  • PSN Structure: On-state behavior at low- and high-level injection, Blocking operation, Voltage limits, Characteristic curves
  • Dynamic behavior of power electronic diodes: Turn-on processes at low- and high-level injection, Turn-off processes, Transition from on-state to blocking, Transition with snubber circuit
  • Thyristor: PNPN structure, Basic equations, Equivalent circuit, Switching characteristic, Blocking characteristic
  • Further thyristor-based structures: Reverse-conducting thyristor, GATT, Triac, GTO
  • MOSFET: Structure, Basic equations, Construction principle, Characteristic curves, Dynamic behavior, CoolMOS (superjunction)
  • Modern Devices: Devices with combined bipolar and MOSFET-structure (IGBT, GCT, MTO, MCT)
  • Thermal characteristics of semiconductors: loss balance, thermal resistances, cooling, damage by power cycling

For further information on the lecture: Campus

 

Electrothermal Process Technology - Basics, Materials, High Power Applications

The lecture presents the interdisciplinary fundamentals of induction technology, as well as some typical applications in high performance applications. In the exercises, practical examples for the dimensioning and selection of appropriate power converter topologies and other process-critical key components are presented.

  • Development and importance of electric heat
  • Fundamentals of electric heat generation
  • Fundamentals of material science
  • Basic principles of heat transfer
  • Industrial process heat applications
  • Components and system components
  • Power electronic topologies
  • Measurement of electro-thermal process variables
  • Resource efficiency and safety

For further information on the lecture: Campus

 

Electrical Drives

Electrical drives are used in many different fields: at home, in industry and for transportation. Dental drills as well as hybrid or fully electric vehicles and ships are powered by electrical motors. The advantages of electrical drives are that electricity is applicable almost everywhere and comparatively easy to decentralize, power and velocity are easy to control, the maximum machine torque is available at zero speed and wear and maintenance costs are low. Particularly due to their high efficiency, electrical drives score well. Since electrical drives consume about 60% of all electrical energy used in industry and gain more and more importance in the field of personal mobility, a huge amount of energy can be saved by an intelligent control of electrical motors. The above mentioned control of electrical motors is the topic of the lecture Electrical Drives. Subsequent to a short introduction to the mechanics of rotating systems the control of all common electrical machines (DC, synchronous, induction and switched reluctance machine) is presented. The universal field oriented (UFO) concept is explained which demonstrates the concepts of modern vector control and exemplifies the seamless transition between so called stator flux and rotor flux oriented control techniques. This powerful tool is used for the development of flux oriented machine models of rotating field machines. These models form the basis of UFO vector control techniques which are covered extensively together with traditional drive concepts. Attention is also given to the dynamic modeling of Switched Reluctance (SR) drives, where a comprehensive set of modelling tools and control techniques is presented. The lecture should appeal to students who have a desire to understand the intricacies of modern electrical drives without loosing sight of the fundamental principles. It brings together the concepts of the ideal rotating transformer (IRTF) and UFO which allows a comprehensive and insightful analysis of AC electrical drives in terms of modeling and control. Extensive use is made of build and play modules which provide the student with the ability to interactively examine and understand the presented topics.

For further information on the lecture: Campus

For further information on the exercice class: Campus

For further information on the consultation hour: Campus

 

Elektrische Energie aus regenerativen Quellen

Content:

  • Energy demand and supply, Global problems of energy supplying
  • Potentional renewable energy sources
  • Cost accounting
  • Photovoltaik: physical basics, manufactoring process,systemtechnic
  • Wind power
  • Water power
  • Other renewable sources: solarthermal, biomass, geothermal etc.
  • Integration of renewable sources in electrical supplying
  • Development level and prospects.

For further information on the lecture: Campus

 

Grundgebiete der Elektrotechnik 2

Professor De Doncker holds this basic lecture for first-year students since the summer semester of 1999. Following a repetition of mathematical fundamentals, the lecture introduces complex ac calculus. In addition, discrete elements like Resistor, Capacitor and Inductor are explained. The transformer is introduced as an element consisting of two magnetically coupled coils. An own section is devoted to the topic of multi-phase systems focusing in particular on the generation of such systems. Subsequently, the three-phase transformer is introduced. The lecture concludes with nonlinear components, circuits and switch-mode power supplies. Great care was taken to organize the course with respect to didactics. Students recognize this regularly with outstandingly good ratings within the faculty's quality management process. The whole lecture uses data projection. Photos, animations and videos are used in order to illustrate lecture contents. Demonstration experiments during the lecture make a connection between theory and practice. Manuscripts are offered for both, the lecture and the practical instruction class. Students gather individual feed-back in small-group practical classes and a test exam.

For further information on the lecture: Campus

 

Elektrische Nahverkehrssysteme

In this lecture, Prof. Müller-Hellmann will talk about recent developments in the field of mass transit systems. Here, questions of technology as well as questions of management are dealt with. The legal framework for the technology, the operation and the financing are comprehensively explained. Urban transport systems and vehicles such as trams, urban, underground and suburban trains as well as novel driverless systems are presented in an overview. Basic considerations such as daily peaks and the highest possible utilization of the trains are explained and solution concepts discussed. In addition, issues of energy supply and safety aspects of electric transport systems are dealt with. As a rule, an excursion to a local transport company completes the lecture.

For further information on the lecture: Campus