REDUCING LOSSES IN HYDROELECTRIC-GENERATOR END ZONES.

Results of investigations into the influence of the nonmagnetic sides of rotor poles and grooves in stator-core end laminations on the magnitude of losses and permissible generator loads are reported. The principal cause of elevated local losses in the outer laminations of the stator cores of hydroelectric generators is the bulging flux from the air gap. A very substantial reduction in local outer-lamination losses is achieved through utilization of nonmagnetic pole side walls (there is a reduction in the length of the ferromagnetic portion of the rotor). A reduction in local losses is also provided if the height of the groove in the outer lamination is increased and grooves are introduced in the next laminations.