Thermal concept

Each machine model is equipped with a machine-specific conditional thermalPort. If useThermalPort == false, a machine-specific thermal ambient prescribing constant temperatures is used inside the machine. If useThermalPort == true, a thermal model or machine-specific thermal ambient prescribing the temperatures has to be connected from outside. On the other hand, all losses are dissipated to this internal or external thermal ambient.

The machine specific thermal connector contains heatPorts for all relevant loss sources of the machine type, although some of the loss sources are not yet implemented; these heatPorts are left unconnected inside the machine, i.e., the HeatFlowRate is zero, but they have to be connected to a constant temperature source in the internal or external thermal ambient. Simple machine-specific thermal ambients for constant temperatures (useTemperatureInputs == false) or temperatures prescribed via signal inputs (useTemperatureInputs == true) are provided in this package.

Loss sources

Up to now, only Ohmic losses in stator and rotor windings are implemented. They are modeled as linearly temperature dependent resistors:

   ROperational = RRef * (1 + alphaRef * (TOperational - TRef))

The linear temperature coefficient alpha20 at 20°C = 293.15 K has to be converted to reference temperature TRef:

  alphaRef = -------------------------------
              1 + alpha20 * (TRef - 293.15)

For this reason, the function convertAlpha is provided. In sub-package Constants linear temperature coefficients at 20°C for commonly used materials are defined.

Backwards compatibility

Machine specific thermalPorts

Asynchronous induction machine with squirrel cage
Asynchronous induction machine with slipring rotor
Synchronous induction machine with permanent magnets
Synchronous induction machine with electrical excitation
Synchronous induction machine with reluctance rotor
DC machine with permanent magnets
DC machine with electrical (shunt) excitation
DC machine with serial excitation
DC machine with compound excitation (not yet implemented)


Name Description
 LinearTemperatureCoefficient20 Linear temperature coefficient with choices
 Constants Material Constants
 convertAlpha Converts alpha from temperature 1 (default 20 degC) to temperature 2
 convertResistance Converts resistance from reference temperature to an actual temperature
 linearTemperatureDependency Converts a value (e.g. resistance) from reference temperature to an actual temperature
 AsynchronousInductionMachines Thermal parts of asynchronous induction machines
 SynchronousInductionMachines Thermal parts of synchronous induction machines
 DCMachines Thermal parts of DC machines
 ThermalAmbientTransformer Thermal ambient for transformers


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