Impact of stator interturn short circuit position on rotor core temperature rising characteristics in turbo - generators

Static air-gap eccentricity ( SAGE) is widely present in generators，resulting in uneven air-gap distribution of generators. The stator interturn short circuit ( SISC ) exhibits positional characteristics in different air-gap lengths. In this paper, the rotor core temperature rising characteristics were analyzed under different SISC positions in turbo -generators. Firstly，the theoretical formulas of the magnetic flux density at different positions were deduced to obtain the detailed core loss expressions. Then the 3D finite element model was set up to calculate the core loss and the temperature of the rotor core. Finally，the experimental verification was carried out on the CS - 5 prototype generator. The test temperature results well accord with the theoretical analysis and the finite element simulation data. It is indicated that the rotor core loss as well as the temperature increases significantly under SISC fault. Particularly, the closer the short circuit position is to the minimum air-gap point, the more the rotor core temperature will be increased. © 2022 Editorial Department of Electric Machines and Control. All rights reserved.