Improvement of the cooling performance of symmetrically self-ventilated induction machines in the 2-15 MW range

Abstract

This paper presents the results of an effort to improve the cooling performance of symmetrically self-ventilated induction machines in the 2-15 MW range. Aerodynamic modifications are applied to the rotor inlet, the rotor bars, the stator bars and the stator cooling gap supports. The modifications are tested in a rotating test rig under laboratory conditions and in a prototype engine. The cooling mass flow and cooling efficiency are increased by more than 10%.