Study of Local Structural Changes on Air Cooling at the End of Rotor Windings for Variable Speed Pumped Storage Generator-Motor

Abstract

The shrink fit retaining ring is currently the easiest to install and the most widely used end fixed for structure AC excitation variable speed generator-motor rotor end windings. However, the current research on the effect of high strength sealing on the ventilation and heat dissipation performance of the end is not enough. In this paper, based on the actual structural parameters and periodic symmetry simplification, the three-dimensional coupled calculation model of fluid field and temperature field is established. After solving the fluid and thermal equations, the influence of the length of rotor support block, the height of rotor support block, and the number of rotor support block on the fluid flow and temperature distribution in the rotor end region of generator-motor is studied using the finite volume method. The rheological characteristics of the air in the rotor domain, such as velocity and interwinding flow, are analyzed. The law of temperature variation with local structure in the computational domain is studied. The variation law of cooling medium performance inside the large variable speed power generator motor is revealed.