Stray Flux-Based Rotation Angle Measurement for Bearing Fault Diagnosis in Variable-Speed BLDC Motors

Abstract

Angle of rotation is a key parameter in motor fault diagnosis under varying speed conditions, and is usually measured by an optical encoder. However, the use of encoders is intrusive and in many scenarios its signal is difficult to access due to technical or commercial reasons. In this study, a novel rotation angle measurement method based on stray flux analysis is proposed and applied to bearing fault diagnosis of brushless direct-current (BLDC) motors. The measurement accuracy of the proposed method is comparable to that from an encoder. The developed method is flexible, noninvasive, and nondestructive. It is easy to implement and eliminates the need for long cables and access of the motor control system. The proposed method can be extended to the diagnosis of motor electrical and drive faults. If implemented with an Internet of Things (IoT) or a hand-held device, it can further improve the reliability of sensorless motor drive systems in industrial automation so as to meet Industry 4.0 requirements. Index terms-Bearing fault, BLDC motors, fault diagnosis, rotation angle measurement, stray flux, vibration signal analysis I. INTRODUCTION Brushless direct current (BLDC) motors are a type of common pivotal actuators used in the field of industrial

Transient Analysis of the Fuzzy Logic-based Speed Control of a Three-phase BLDC Motor

“…Energy-efficient industrial drives are becoming more and more necessary in emerging industrial and residential applications. One such advancement is in BLDCMs [1][2][3], which have much more efficiency than the single-phase induction motor, high torque-to-power ratio, require less maintenance, and have a fast reaction to commands. BLDC motors need an electronic commutator, which is a major shortcoming.…”