A Geometrical Interpretation of Current Space Vector Components Due to Induction Machines Rotor Faults

This paper presents a deep investigation on the rotor fault signatures of induction machines. Phase current and current space vector sidebands, spectral components of flux, torque and speed are analyzed as functions of inertia, load and machine size. Analytical expressions among the physical quantities, validated by simulation and experimental results, are developed using a synchronous reference frame. These expressions, together with geometrical loci showing the vector relationships among the quantities involved, allow a thorough understanding of the underlying physical phenomena. A test-bed able to realize a variable virtual inertia allows the experimental validation as well.