Search

This paper investigates a novel online method for static eccentricity (SE) fault detection of single-stator–single-rotor axial flux permanent-magnet (AFPM) machines. The method allows for both estimating the SE factor and computing the minimum air-gap position. As direct flux measurements are expensive, the proposed method for fault detection is based on the measurement of the voltages of three search coils uniformly distributed in the air gap. Unlike the current spectrum-based fault detection methods on which the winding configuration has a considerable impact, the proposed method can be used for any type of AFPM machine independently on the winding layout. A simplified 2-D analytical approach is used. Moreover, a circuit-coupled 3-D finite-element method (FEM) was used to compute the induced voltages in the search coils and show the validity of the method through 20 eccentric scenarios. Moreover, an experimental setup was built to validate the analytical approach and to confirm the results achieved with the 3-D FEM. Several experimental measurements have been done. All measurements confirm the accuracy of the proposed method. It is also shown that the method yields accurate results under any load condition. [ABSTRACT FROM PUBLISHER]

This paper studies static eccentricity (SE) fault detection in axial-flux permanent-magnet (AFPM) machines using 3-D finite-element analysis. The use of numerical modeling makes it possible to precisely study the eccentricity fault detection in these types of machines. The simulations are validated using experimental measurements. To the best knowledge of the authors, SE fault detection in AFPMs has not been studied before. Hence, a new definition for the SE factor is presented in these types of machines. A motor with different degrees of rotor eccentricity is simulated, and the back electromotive force (EMF) of all coils of the stator is obtained. In addition, an appropriate criterion has been presented for the fault detection using the back EMF of the coils. This study indicates that the back EMF of the coils of the stator is a good criterion for eccentricity fault detection. It is observed that the unbalanced back EMF suggests a method for the indirect measurement of eccentricity that could be carried out during manufacturing and assembling processes or maintenance operation. [ABSTRACT FROM AUTHOR]

This paper studies the effects of static eccentricity on axial flux permanent-magnet machines (AFPMMs) using three-dimensional finite-element analysis (3-D FEA). Use of numerical modeling makes it possible to precisely study the eccentricity in these types of machines. The accuracy of the FEM model is validated using experimental measurement. To the best awareness of the authors, effects of static eccentricity in AFPMMs have not been studied before. Hence, a new definition for the static eccentricity factor (SEF) is presented and it is shown that the occurrence of static eccentricity is very high in these types of machines. A motor with different degrees of rotor eccentricity is simulated and the flux density distribution in the air gap and the total axial force between rotor and stator is obtained. In addition, unbalanced magnetic force (UMF) is calculated and it is mentioned that a steady torque is created by the forces. This study indicates that static eccentricity has noticeable effects on motor characteristics and can deteriorate the motor performances. [ABSTRACT FROM PUBLISHER]