His research dealt with:

 

 

Time:     08:00

 

Date:     7 December 2007

 

Venue:   Engineering I, Room 9-7

 

Study Leader: Prof PS Heyns

 

 Abstract:

Conventional rotating machine vibration monitoring techniques are based on the assumption that changes in the measured structural response are caused by deterioration in the condition of the rotating machine. However, due to changing rotational speed, the measured signal may be non-stationary and difficult to interpret. For this reason the order tracking technique was introduced. One of main advantages of order tracking over traditional vibration monitoring techniques lies in its ability to clearly identify non-stationary vibration data, and to a large extent exclude the influences from varying rotational speed. This work investigates the application of the Vold-Kalman Filtered Order Tracking (VKF-OT) on electrical machinery.

Simulated single-degree-of freedom and two-degree-of freedom rotor models were established, and the application of the VKF-OT technique on these simulated models was explored. Because most of the current research draws significantly on an understanding of the VKF-OT theory, it was also necessary to review and summarize the current status of VKF-OT theory from previous work, as well as explore the procedures for selection of its filter bandwidth when dealing with real data. An experimental set-up for monitoring an electrical alternator was also constructed. Real experimental data were subsequently used to compare the advantages and disadvantages of the three popular order tracking techniques. The unique time domain advantage of VKF-OT was implemented, using crest factor and kurtosis values as indictors of the fault condition of the machine. This gave encouraging results.