ANSYS-Based Broken Magnet, Demagnetization and Short Circuit Fault Evaluation for a BLDC Motor Designed for Light Electric Vehicle

Abstract

With the growing adoption of light electric vehicles (LEVs), it is becoming increasingly important to optimize their propulsion systems. Brushless DC (BLDC) motors are widely utilized for their high efficiency, precise control, and strong performance. Nevertheless, their reliability faces challenges from various operational failures that can greatly affect the functionality of the vehicle. This study employs Finite Element Method (FEM) analysis to investigate and quantify the effects of specific faults in BLDC motors, with a focus on magnet and stator insulation issues. Two primary types of magnet faults—broken magnets and demagnetization—are explored. Our findings indicate that the severity of these faults correlates directly with adverse effects on motor performance, including changes in current levels, torque, and magnetic flux density. A simulated reduction in magnet coercivity by 30% showcases critical consequences such as increased current draw and failure to generate net torque, highlighting potential performance degradation under high-temperature conditions or other stressors. Additionally, the study examines the impacts of unbalanced single-phase short circuits, which increase harmonic content and torque oscillations, further degrading motor performance. By demonstrating the significant influence of these faults through detailed FEM analysis, this research underlines the necessity for robust motor design and proactive maintenance to enhance the reliability and efficiency of LEVs. This work contributes valuable insights into the fault dynamics of BLDC motors, providing a valuable reference for engineers and researchers in the field of electric vehicle propulsion systems.