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This paper introduces a novel index for static eccentricity (SE) fault diagnosis in synchronous reluctance motors (SynRMs). Although SynRMs with rotor barriers under SE have been modeled in a few papers, any indices for the fault detection have not yet been reported. The proposed index is a specific frequency pattern in the motor current, which can also determine the fault severity. A novel analytical magnetic field investigation is applied to ascertain the proposed index. An accurate nonlinear numerical method is proposed for the motor inductances calculation. The model considers the rotor flux barriers, magnetic saturation, and the stator slots effect. The air gap flux density and the motor current are then achieved. The fast Fourier transform is exploited as a signal-processing tool to calculate motor current spectra. Then, a two-dimension time-stepping finite element method is used to attest of the proposed numerical model. Effectiveness of the proposed index is verified by simulation and experimental tests. [ABSTRACT FROM AUTHOR]

The brushless doubly-fed induction machine (BDFIM) shows interesting features for incorporating as wind generator or variable speed drive. The BDFIM operation is based on magnetic flow modulation of two stator winding fields through a special squirrel cage rotor. Hence, the power flow is very different from that of a regular induction machine. Taking into account, accurate analysis of the power flow is very valuable for the comprehension and design of BDFIM as well as the selection of converter capacity. In this paper, the power balance for BDFIM is discussed in the motoring and the generating modes and for both super- and sub-synchronous speed intervals. For this purpose, the power flow equations are extracted and power flow diagrams taking into account all the power loss components are presented. The accuracy of the proposed power flow diagrams is verified by comparing the obtained results with the experimental and finite element ones. [ABSTRACT FROM AUTHOR]