New specs for ASD motors

The two main issues in pulse-width modulated ASD motors namely: stress concentration at slot exits and at junctions between stress grading and corona protection materials, and winding insulation aging due to partial discharge and/or dielectric heating, often intensified between turns as well as across the main-wall of the stator coils. This paper explores the IEC-60034-18-41 and IEC-60034-18-42 technical specifications for inverter duty motor insulation. These specifications describe the qualification and acceptance tests for both low and medium voltage motor windings in order to ensure reliability