Wind turbine operation normally leads to a great deal of noise production , thus preventing their widespread use particularly near residential areas.Additionally a gigantic wind turbine on the roof isn’t exactly visually appealing.A way around this problem is to operate the turbine under partial load to limit the noise production.However this also reduces the power output associated with the turbine.Damping systems used till now were of passive kind and in some cases even entail replacing the gearbox which is an expensive proposition.Passive systems are capable of absorbing noise at a certain frequency and in turn produce a humming sound which in turn penetrates the surrounding areas and sometimes cause more discomfort than actual noise.
In a project funded by the Deutsche Bundesstiftung Umwelt researchers are developing an active damping system for wind turbines.These systems are dynamic in operation that is they react autonomously to any change in frequency , irrespective of the speed of turbine operation.This system uses piezo actuators which convert electricity into mechanical motion and cancel out the vibrations produced by the turbines. A working model of the system is already in place and field trials are expected soon.The challenge however would be to integrate these sensors with the mainstream turbine control system in a cost effective manner.
