Abstract:
Wind turbines are the most developed renewable energy prospects that are used to capture kinetic
energy from the wind and generate electricity. Modern large-scale wind turbines are subjected to
different sorts of failures, such as main bearings, gearboxes, and generators. Moreover, downtime
loss will make a huge impact on the cost of energy. Thus, the rapid development of the wind power
industry requires a gearbox with higher performance. The dynamic characteristics of gearboxes
study before and during the operation will decrease operation and maintenance (O&M) costs,
both of which would greatly reduce the economic benefit of wind power. The study of dynamic
characteristics of wind power gearbox works on the prevention of failures in the wind turbine. The
existence and application of modeling and analysis software will reduce the task and increase the
accuracy.
This thesis presents, the influence of variation of input rotational speed on the vibration signal of
SE7715 wind turbine drive train at Adama Wind Farm Ⅱ. The dynamic model of the gearbox
transmission system is built into the ADAMS for simulation. The wind turbine gearbox vibration
signal is simulated to monitor the technical conditions of rotating components at three different
load cases with input rotational speeds at 10 rpm, 15 rpm, and 20 rpm. The gears vibration signal
of angular acceleration and gear force are considered in the simulation and the results are
analyzed through Fast Fourier Transform (FFT) by using ADAMS.
Depending on the simulation results, the vibration signal peak points of load case 3 (20 rpm) is
greater than other load cases and these indicate the vibration signal is dependent on the variation
of input rotational speed. As the rotational speed increases the vibrational signal also becomes
higher. The results also show the influence of input rotational speed on the gear force at the three
load cases, at the highest input rotation speed (20 rpm), the amplitude of gear force is higher than
the other load cases and at 10 rpm input rotational speed, the amplitude is lower than other load
cases. Therefore, input rotation variation has a great effect on vibration signal of gears and gear
force.
