Noise and vibration monitoring for diagnosis of DC motor´s faults

This paper describes faults detection and diagnosis of permanent magnet dc electric motors based on noise and vibration monitoring. Detection and diagnosis of incipient faults are desirable in order to ensure product quality and improved operational efficiency of electrical equipment and to avoid the power off from supply mains. In order to do the diagnosis there are analyzed noises from the microphones and vibration from the piezoelectric accelerometer. The microphones are installed around of the frame of the equipment and the accelerometer is mounted on the frame´s motor. The Fast Fourier Transform is applied to the acquired signals. We observe significant noise and vibration spectrum differences between “healthy” motors and fault´s electrical motor. The high-frequency spectral analysis of noise and vibration provides a method to detect motors faults.