This course is offered in German.
Learning objective:
The module expands on the basic knowledge of synchronous and induction machines with specific insights into their operating behavior in the entire drive system, i.e. the interactions with the grid or frequency converter on the one hand and the driven equipment on the other hand. Students learn to independently analyze practically relevant interactions such as torsional vibrations during start-up, during operation with a frequency converter or during transient processes, to assess the specific properties of the possible combinations of frequency converter and electric machine, as well as important non-electrical effects on cooling, bearings or noise generation, and to design the start-up and electrical braking methods of grid connected three-phase machines according to requirements.
Contents:
- Operating behavior of induction machines considering the stator winding resistance
- Characteristics of the machine types when switching on and during start-up: consideration of the peak currents, the heating and the torque-speed characteristic curve including pull-up torque formation, starting assistance
- Electrical braking methods for the different machine types: counter-current braking, direct current braking, regenerative braking
- Speed variation of induction and synchronous motors: Basic power electronic circuits, comparison in terms of additional costs and losses, generation of torque pulsations
- Heating and cooling of electric machines: cooling concepts, determining the winding temperature, duty types, energy efficiency requirements, thermal limit curves
- Failures: Introduction to the calculation methods of symmetrical components of instantaneous values and of the park transformation (voltage equations, instantaneous value of the electromagnetic torque) for simulating transient processes, simulation of the mechanical drive train, consideration of the transient current displacement, transient behavior of induction machines (start-up, symmetrical and asymmetrical terminal short circuits, change of supply), transient behavior of synchronous machines (asynchronous start-up, influence of damper windings and rotor anisotropies, symmetrical and asymmetrical terminal short-circuits from no-load or loaded operation, non-ideal synchronization), reactances and time constants of synchronous machines
- Design aspects of drive systems: types of construction, degrees of protection, explosion-proof machines, mutual influence of coupling and bearing types, bearing voltages and currents
- Acoustics of electric drive systems: considerations regarding noise generation and its assessment
- Standardization and standards for rotating electric machines
Previous Knowledge:
Principles of electromagnetic power conversio
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