Understanding of vibration and noise characteristics of inverter-driven fan motors and proposal of sound quality improvement methods

Abstract

Fan motors used for cooling data servers are generally controlled by inverters to save energy and reduce noise.At this time, noise is generated due to the inverter.Even manufacturers have taken noise countermeasures, it is difficult to reduce the noise completely.In this research, we focus on the output current of the inverter to qualify the current characteristics that cause noise. Furthermore, the noise countermeasures which were taken by manufacturers were investigated ,and the connection between the current characteristics and sound quality of the fan motor. From these results, we aim to propose a sound quality improvement method by changing the inverter output.