Samples for recent work:

inverter operation of asynchronous machines

Starting with a harmonic analysis of the feeding voltage (resp. feeding current) according to the T - equivalent circuit diagram additional losses and harmonic torques are calculated taking eddy currents into consideration.


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temperature distribution stationary / dynamic

According to the structure of an electrical machine and the cooling method a lumped circuit (consisting of loss sources, thermal capacities and resistances) is assembled flexibly. For this purposes a Modelica-library with simple components for modeling coolant flows was developed.
Special thanks to Martin Otter!


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analysis of windings

Distribution of the windings to the stator slots defines the curve of field excitation, which will be analysed. Additionally winding factor and harmonic stray factor is calculated.


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starting of asynchronous motors

Considering the voltage-drop at the line impedances due to the starting-current of the motor the motor's torque minus the load torque accelerates inertia of the drive.


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Losses during operational cycles

Taking the asynchronous machine's T - equivalent circuit diagram the losses are calculated for each time slice of the cycle;
losses and reactances are adapted to the variable saturation due to inverter operation.
Traget is to calculation of an equivalent constant power or to check thermal stress of the choosen motor.


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active compensation of voltage drops

Not only active, but also reactive and harmonic currents cause unwanted voltage drops at line impedances. This tool demonstrates the effect of exact compensating injection of reactive and harmonic currents.


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simulation of diode rectifiers

Using a Modelica-simulation it is possible to identify mains load and DC-voltage of a diode rectifier at different network conditions and DC burdens.


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dynamic simulation of asynchronous motors

A Modelica-Library for dynamic simulation of electrical machines is under permanent further development. This enables flexible simulation of different operation conditions: start-up, short-circuit, load impulse, ...


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Results: Here You get a short summary of space phasor theory.
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