Vibration Analysis of the Low Speed Shaft and Hub of a Wind Turbine Using Sub Structuring Techniques

The wind turbine vibration causes dynamic instability of components of the transmission system desired to generate electricity. The vibration motion of the hub relative to the shaft need to be studied in order to improve durability of components part and ensure that a good percentage of wind energy captured is transmitted to electricity. This paper attempts to do that. A sub-structuring technique was adopted in the analysis of the vibration motion. Firstly, the finite element equation was derived for the hub and shaft structures before coupling. After coupling, the appropriate boundary condition was used to minimize the system complexities. The solution to the eigenvalue problem was then developed using MATLAB. This results obtained show that sub-structuring is a suitable technique for the dynamic analysis of the transmission system of a wind turbine as compared with other approaches.