Analytical electromagnetic analysis of multi-phases cage rotor induction motors in healthy, broken bars and open phases conditions

Abstract

This paper presents an analytical calculation of magnetic field and electromagnetic performances of 3-, 5-, 7-, 9-, 11-phases cage rotor induction machines in healthy, broken bars and open phase's conditions. This model is formulated to consider all types of multi-phase/multipoles windings and used for the identification of electrical equivalent circuit (EEC) parameters It's based on the subdomain model and the resolution of Poisson's, Laplace's, and Helmholtz's equations in each subdomain issued from Maxwell equations using the method of separation of variables and Fourier series when the machines are fed with sinusoidal current and voltage. The developed analytical model permits the calculation of magnetic field distribution, eddy current, circuit model parameters, and unbalanced magnetic radial force due to broken bars, electromagnetic torque and absorbed stator current. A comparative analysis between the studied five multi-phases machines is done with considering identical power rate. The analytical results are validated by those issued from the finite-element method (FEM).