A Study of Stress Grading of MV Motor Coils Energized by Repetitive Fast Pulses

The paper discusses the thermal stresses on the electrical stress grading of a 13.8 kV motor coil when energized by pulse width modulated voltages. The effect of the pulse rise time in the temperature profile at the end portion of the motor bar is measured experimentally. AC dielectric and thermal properties of the materials are also measured. The thermal stress due to two equivalent high frequency sinusoidal voltages is analyzed using 3D FEM coupled electrical and thermal modelling.

کلیدواژه ها:

fast pulses ، stress grading ، corona ، surface discharges ، thermal stress ، motor coils