Research on Vibration and Noise Reduction Driving Strategy of Piezoelectric High-Speed On/Off Valve

Abstract

The piezoelectric high-speed on/off valve encounters two primary challenges under high-frequency PWM driving conditions: electromagnetic noise resulting from the high-frequency charging and discharging of piezoelectric materials, and mechanical noise arising from the rapid, high-frequency impact between the valve core and the valve seat. In order to solve this problem, this study proposes a vibration and noise reduction PWM (VNR-PWM) strategy based on second-order S-curve, aiming at realizing the soft-start and soft landing of the spool by optimizing the variation rules of the rising and falling curves in the PWM excitation voltage signal of the piezoelectric high-speed on/off valve. The optimal parameter combinations of delay time T0 and acceleration time tacc in the VNR-PWM strategy are determined through simulation analysis. A prototype was developed, and then, it was tested on an experimental bench to verify the performance of the VNR-PWM strategy. The vibration and noise experiments show that the opening and closing noise of the high-speed on/off valve is 70 dB and 80 dB respectively under the 0.25 Hz and 200 Hz vibration and noise reduction PWM driving strategies. Compared with the traditional PWM driving strategy, the opening and closing noise is reduced by 12.5% and 16.3%, respectively. The acceleration test of the valve block shows that under the vibration and noise reduction PWM drive strategy, the vibration acceleration of the valve block is reduced from 1130 m/s2 to 265 m/s2 (closing process) and 570 m/s2 to 170 m/s2 (opening process), with a decrease of about 76.5% and 70.2%.

Keywords: Piezoelectric high-speed on/off valve, Electromagnetic noise, Mechanical noise, Vibration and noise reduction PWM, Soft landing