Static Eccentricity Fault Detection in Brushless Doubly Fed Induction Machines based on MotorCurrent Signature Analysis

In this paper a new rotor eccentricity fault detection method is proposed for the first time for Brushless Doubly Fed Induction Machines (BDFIMs). Due to the fact that BDFIMs are attractive alternatives to doubly fed induction machines for wind power generation, paying attention to their fault diagnosis is essential. Existing fault detection methods for conventional induction machines can not be directly applied to the BDFIM due to its special rotor structure and stator winding configurations as well as the complex magnetic fields. In this paper a new fault detection technique based on stator current harmonic analysis is proposed to detect rotor eccentricity faults in the BDFIM. The validity of the proposed fault detection method is verified by analytical winding function method and finite element analysis on a prototype D180 BDFIM.
Index Terms—Brushless doubly fed induction machines, Nested-loop rotor slot harmonics, Motor current signature analysis, Winding function method, Finite element analysis, Static eccentricity fault.