Strategic High-Frequency Switching of Idle Phases for Static & Dynamic Eccentricity Detection in Switched Reluctance Motors

Switched reluctance motors (SRMs) inherently exhibit issues such as torque ripples, noise, and vibrations, which are exacerbated by eccentricities. Eccentricity, one of the most common mechanical faults in SRMs, worsens with continued operation due to unbalanced magnetic pull. In extreme cases, this can lead to physical contact between the stator and rotor poles, causing irreversible damage to the motor. This article presents a scheme for the online diagnosis of static eccentricity (SE) and dynamic eccentricity (DE) in SRMs by switching the phases at a higher frequency in their respective negative torque regions. This technique leverages variations in inductance profiles caused by eccentricities to identify and distinguish between SE and DE, and to detect the phase along with which the rotor pole has shifted in case of SE. The proposed scheme has been validated through finite element method-based simulations in an ANSYS Maxwell environment for a 4-phase 8/6 SRM.