Abstract
This paper investigates the prominence discrete tone (PDT) noise originating from the driving method of a hard disk drive (HDD) spindle motor with 12 poles and 9 slots. Torque ripple of a HDD is reconstructed by the multiplication of measured back electromotive force (BEMF) and measured switching current. It shows that the frequency components of PDT noise match with those of torque ripple. It also investigates the frequency change of PDT noise due to two driving methods which have the different switching-off periods to detect the zero-crossing of the BEMF. The BEMF has odd harmonics of the number of pole pair, but the current has even harmonics of the number of pole pair due to the switching-off period as well as those odd harmonics of BEMF. We theoretically derive the torque equation in terms of the frequency components of BEMF and switching current. We also verify that the even harmonics of the driving current due to driving method generate the 54th harmonic of torque ripple, and show that the pure sinusoidal BEMF with the 6th harmonic can decrease the 36th harmonic of torque ripple as well as PDT noise in the HDD spindle systems.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
