Impact wear phenomena of ground insulation in slot section

An investigation has been conducted to clarify the impact wear behavior of mica-splitting and Nomex insulations under dynamic loading. A new method of impact wear testing has been developed which is primary applicable to evaluation of the impact wear resistance of the insulation constructions. The impact wear test consists of exciting the top coil out of the top and bottom coils inserted into the model slot. Impact wear phenomena have been determined from the variations in the waveshapes and magnitudes of the load and displacement. Some discussion are made on the effects of the insulation materials, the bonding between the coils and the core, and the initial clearance between the top coil and the wedge on the impact wear of the insulation coils. The mechanisms of the impact wear are also discussed.