Development of Polymer-Ceramic Composite Materials for the Winding
Insulation of Highly Utilized and Energy-Efficient Electrical Machines
- Sören Miersch ,
- Ralph Schubert ,
- thomas schuhmann ,
- Mathias Lindner
Abstract
The electromagnetic utilization of an electrical machine can be
increased by raising the current density, with a limitation resulting
from the maximum permissible temperature of the winding insulation.
Conventional insulating materials only have a low specific thermal
conductivity, which results in large temperature gradients in the
winding cross-section and consequently hotspots. The article presents
the development and characterization of ceramic-like composite materials
based on filled polysiloxanes for the dip coating of lamination stacks
and the impregnation of the winding of electrical machines. The specific
equivalent thermal conductivity is determined on composite winding
samples, the thermal cycle stability is examined and the microstructure
is analyzed with the scanning electron microscope. The manufacturability
and the partial discharge behavior are examined based on test samples.
The results of tests on an electric traction machine are used to show
the potential for increasing the power density.