In this paper, the impact of control on faulted induction machine behavior
is presented. The diagnostic indexes usually used for open-loop operation a
re no longer effective. Simulation and experimental results show that the s
pectrum of the field current component i(d) in a field-oriented controlled
machine has suitable features that can lead to an effective diagnostic proc
edure. Specifically,,in the case of stator and rotor faults the id spectrum
components at frequencies 2f and 2sf, respectively, are quite independent
of control parameters and dependent on the fault extent.