Research areas

Basics

A    Methodology, modeling, simulation, tools for machines and drives

Methods for modeling, designing and dimensioning, controlling as well as optimizing the individual components of machines and power converters and the energy conversion system in principle also the solution of individual questions for the design and layout of machines are the focus. These highly method-oriented works will particularly support development projects of companies in the regional environment of the university or receive suggestions from them. In detail, these are:

• Magnetic circuit and winding design of electrical machines, in particular of PM synchronous machines, using 2D and 3D FEM simulations in conjunction with classical design methods
• System analysis of converter-fed machines and measuring campaigns on winding stress, bearing current effects, additional losses, etc.
• Control of drives and generators in particular energy-efficient methods

B    Industrial electronics - power converters

The research in the field of industrial electronics should focus on the power converter technology for energy converters (motors, generators). New semiconductor power devices are the basis of research in energy-efficient converter topologies and their design and specific application are the focus.

• Voltage converter
• Matrix converter
• Z-Source converter
• Control method for drive converter
• Bearing current minimizing control method

Applications

C    Magnetic bearing technology - mechatronics

For magnetic bearings, the focus is on a low-loss bearing and thus on the reduction of significant frictional losses at fast-rotating drives and on the other hand, a considerable increase in precision. For this purpose, a collaboration with mechanical engineering professors will be sought. For direct drives (linear motor, torque motor), solutions are to be worked on to increase the still unsatisfactory efficiencies (energy efficiency) compared to motors with gearboxes. Since both active magnetic bearings and direct drives are in regulated operation, the sensor system for detecting mechanical variables is of particular importance. In detail, these are:

• New materials and constructions for magnetic bearings up to 100 000 1 / min
• Magnetic circuit and controller design for high-speed magnetic bearings
• Bearingless reluctance motors and PM synchronous motors

D    Regenerative energy sources

Another application focus will be on regenerative electromechanical energy converters, especially for wind turbines. Priority is given to mass and loss-reduced generators, energy-efficient conversion technologies using special converters and control methods as well as to a demand-oriented regulated grid feed-in. In detail, these are:

• Double-fed asynchronous slip ring generators (generator optimization, harmonic analysis, loss optimization, grid-compatible control)
• PM synchronous generators (design-accompanying FEM analyzes, generator and converter control)
• Direct power control

E    Hybrid and electric vehicle

The development of special electro-mechanical energy converters and low-inertia or high-torque traction motors as well as the design of suitable control methods should be intensified. The work could be conducted in cooperation with other professors for the optimization of electric-mechanical drive trains. Since hybrid drive technology is expected to be only a necessary sub-step to the technical solution of purely electrical drive with fuel cell and traction motor, those already initiated basic projects of energy management for fuel cell power supply (DFG) should be continued and further extended to automotive applications.

• Power-split drive trains, in particular electric machines with coupled and simple converters
• Special power converter for fuel cell drives

F    Cooling of electrical machines

A new research focus will be on the cooling of electrical machines and drives. Based on qualitatively new simulation and development tools (3D modeling, multiphysics modeling), it will be necessary to develop efficient cooling methods for compact motors, to replace water cooling by air cooling and to bring new design options such as cross-cooling or heat pipe to technical maturity. This goal should also be supported by close cooperation with the TU Chair for Heat and Material Transfer (Prof. Huhn) and synergies with HTW Dresden.

• Cross-cooling of electrical machines
• Methodology for coupling magnetic, thermal and fluidic fields
• Detailed problem analysis