Partial Discharge Resistance of Insulation Systems in Electrical Machines

  Lifetime curve of different materials Copyright: © IEM Schematic comparison of the lifetime curves of conventional insulation materials and materials filled with nanoparticles.

For the series development of electric drive motors, the correct dimensioning of the insulation system is essential to guarantee a reliable operation of the electrical machine. Therefore, the electrothermal resistance of the insulation system must be determined in the design process. New challenges are being posed to the insulation system through the planned increase in DC link voltage to 800 V and the use of fast-switching silicon carbide (SiC) semiconductors in automotive traction drives. Normative specifications provide a design for worst-case conditions, which may lead to over-dimensioning of the insulation system. The investigation of modern insulation materials, which are filled with inorganic nanoparticles leading to a high resistance to aging processes, should challenge current design criteria and allow for a more customized design of insulation systems. In addition, boundary conditions that are not taken into account in the normative specifications, such as the ambient air pressure, are examined.