Construction, design and simulation of electric drives

Electromagnetic design

Field pattern of the induction distribution of a synchronous machine.
© Fraunhofer IFAM

Field pattern of the induction distribution of a synchronous machine.

The electromagnetic design of electric machines, such as synchronous and asynchronous machines, are among the core competencies of the Electric Drive Systems Department. Both analytical and numerical methods of calculation are used for the dimensioning of the electric machine regarding the optimal use of the assembly space. The ANSYS Maxwell simulation software is available for 2D and 3D simulations. Thus, detailed calculations can be performed for complex relationships, such as:

  • Nonlinearities through saturation effects
  • Current displacements in the conductors
  • Eddy current losses in conductive areas
  • Torque ripple due to parasitic harmonic waves

The characteristic diagrams for optimal efficiency, which are subsequently generated based on the simulation results considering all mechanisms of loss, provide initial estimates on energy consumptions for real load profiles and/or normal cycles.

Thermal design

Thermography image of a cast coil.
© Fraunhofer IFAM

Thermography image of a cast coil.

Thermal considerations are also necessary for an optimal design of electric machines. This includes:

  • Development of thermal substitute models and thermal simulations
  • Evaluation of production-technical influences on the thermal behavior (in particular slot insulation, fill factor, thermal housing connection)
  • Development of cooling concepts for electric machines with water and air cooling
  • Metrological validation of models and machine behaviors through thermographic measurements

Construction and mechanical design

CAD-complete model of a wheel hub motor.
© Fraunhofer IFAM

CAD-complete model of a wheel hub motor.

The mechanical design and construction of housing components and bundles of laminates of electric machines is a further component of this department. This includes:

  • Ready-for-manufacture design, in particular for highly productive casting processes
  • Design of interference fits regarding temperature and torque transferability
  • Numerical calculation of the mechanical strength of the whole system under real-world loads

The CAD software CATIA V5 as well as Abaqus von Dassault Systèmes are hereby used.