Performance of the Noise and Vibration of the AC/DC Signal for a Permanent Magnetic DC Motor

Herein, a single-phase dc permanent magnet motor (PMM) operated at direct current (dc) was proposed, affected by a type of alternating current (ac) signal >5% and frequency between 50 and 3000 Hz to explore characteristics such as noise, vibration, and motor power efficiency. The finite-element method (FEA) was used to model the motor and the transient results of the core flux and current were simulated. The noise level of the motor was experimentally determined for the motor under normal dc power operation subjected to higher hybrid power supply. This indicates that the vibration displacement (mm) and velocity (mm/s) vary, while acceleration (mm/s2) is linearly stable. From the experimental results, the vibration is inversely proportional to the noise. The lower noise level is only observed under medium frequency, similar to a bathtub curve. In addition, when the motor is operated at a low frequency of 50-500 Hz, the characteristics of the power performance were increased more than 1.5 times, including real power P (real power, Watt), apparent power S (apparent power, VA), and reactive power Q (reactive power, VAR), which is much higher than the high-frequency power signal at frequency >500 Hz, gradually stabilizing the motor power. Moreover, a hybrid ac signal of up to 15% was added to the motor system at a frequency between 50 and 500 Hz, drastically changing the displacement and vibration by up to 1.36 times. However, at high frequencies of >1 kHz, the power and noise increase slightly before reaching the steady state.