Electrical Insulation Stresses in PWM-Driven Electric Machines2 Februarie 2021
Ora: 18:00 (Romania)
With the application of wide bandgap power electronics in electric machine drive systems, engineers and researchers are concerned that the higher dv/dt rate will accelerate the degradation of the insulation system in variable speed drives. It is not well understood which part of the machine insulation should be strengthened and which part could be reduced. Thus, high precision modeling, simulation and test methods are needed to predict voltage stress and current distribution in machine windings to reach an optimal design to ensure the reliability within reasonable design margins.
This seminar will discuss the finite element modeling, mathematical modeling and experimental testing of the voltage stress and current distribution inside electric machine windings driven by PWM voltage excitations. Both the stranded random-wound windings and bar-wound windings will be used in the teaching demonstration. The voltage stress considered includes the voltage across individual turns, the voltage between any two turns, and the voltage between any turn and the stator ground wall during power electronics switching transients and steady state. The current distribution includes the currents in parallel wires and the current distribution within each conductor for the bar-wound winding case.