Simulation of an Induction Motor's Rotor after Connection

© 1965-2012 IEEE. Transients have proven to be a specially demanding operation mode for rotor cages in induction motors. The combination of thermal and mechanical stresses causes damage in weak points of the secondary circuit of these machines. A 3-D multiphysics computation may shed some light into the conditions under faults, such as broken bars developing, while taking into account phenomena as interbar currents. With the aim of reducing the computational cost involved, this paper carries out a 3-D simulation of just the rotor during the first 2.5 cycles after a direct-on-line connection, with the tangential component of the magnetic vector potential mapped on its iron surface from the results obtained by the 2-D locked rotor finite-element simulation. The results provide an insight into the skin effect and mechanical loads in the cage, a magnetic coupling between the end ring and the shaft, as well as the limitations of the weakly coupled magnetoelastic analysis

Combined Model for Simulating the Effect of Transients on a Damaged Rotor Cage

© 2017 IEEE. The expansion of the transient operation of electrical machines as, for instance, in vehicle traction applications, demands an accurate computation of the thermal behavior under these conditions in order to enhance the economy of the design and provide a precise estimation of the overload capacity. In addition, heavy transients have been identified as specially damaging for the rotor cage of large induction motors. The aim of this paper is the development of a model able to simulate in detail the thermal and mechanical effects of a heavy transient on an induction's motor rotor featuring a damaged (with a reduced section on one of its ends) rotor bar. Some preliminary results that provide a qualitative understanding of the development of a bar breakage during a fatigue test are presented