Study of a Low-Cost Piezoelectric Sensor for Three Phase Induction Motor Load Estimation

Abstract

Due the complexity of control and automation networks in modern industries, sensor-based systems stand out as effective approaches for failure detection in electrical and mechanical machines. This kind of intervention has a high operational value in industrial scenarios, once it can avoid corrective maintenance stops, i.e., before the failure reaches a high level of severity and compromises the machine. Consequently, the development of sensors applied to non-destructive techniques (NDT) for failure monitoring in electrical machines has become a recurrent theme in recent studies. In this context, this paper investigates the application of low-cost piezoelectric sensors for vibration analysis, which is an NDT that has already proved to be efficient for the detection of many structural anomalies in induction motors. Further, the proposed work presents a low-cost alternative approach for expensive commercial sensors, which will make this NDT more attractive for industrial applications. To describe the piezoelectric sensor frequency response, a pencil lead break (PLB) test was performed. After this validation, the Root Mean Square (RMS) value from the voltage samples obtained in the test bench was used as a signal processing method. A comparison between the results for different levels of mechanical load attached to the machine shaft indicated not only the successful performance of the low-cost sensors for load estimation purposes, but also showed that oversized motors may present higher vibration levels in some components that could cause mechanical wearing.

Undervoltage Identification in Three Phase Induction Motor Using Low-Cost Piezoelectric Sensors and STFT Technique

“…The sensors used in this research were the piezoelectric diaphragms, which are similar to PZT ceramics. Also called buzzers, these components were generally applied as sound generators, however, many recent studies have used them as an AE sensor successfully [9,10]. These diaphragms have a circular brass plate with a diameter of 20 mm that houses a circular piezoelectric ceramic with a diameter of 14 mm, which is coated by a metallic film for electrical contact (Figure 1).…”

Identification of Stator Winding Insulation Faults in Three-Phase Induction Motors Using MEMS Accelerometers

“…The root mean square (RMS) technique is a method that has been proven successful when applied for vibration analysis. Previous work has shown that this technique is effective not only in characterization and diagnosis, but also in monitoring and estimating indicators of TIM faults [13]. Furthermore, the Equation:…”

“…is described for discrete sampling, with n being the number of samples collected, and n v the value for the nth sample of the signal [13].…”

Vibration Monitoring for Position Sensor Fault Diagnosis in Brushless DC Motor Drives

“…Thus, vibration monitoring has already been proposed for bearing, rotor, stator, and gear or axis fault diagnosis, mostly for induction motors and wind turbines [3][4][5][6][7][8][9][10]. Additional applications of piezoelectric sensors are recently reported in [11,12] for load estimation and undervoltage detection also in induction motor drives. Relative research has also been conducted for fault diagnosis of other electrical motor types, such as permanent magnet DC motors [13], while stator fault monitoring of brushless DC (BLDC) motors is presented in [14,15].…”