Instantaneous Angular Speed Monitoring of a 2MW Wind Turbine Using a Parametrization Process

Abstract

One cannot but notice that a variable speed wind turbine utilizes the available wind resource more efficiently than a fixed speed wind turbine, especially during light wind conditions. Most wind turbines are equipped with doubly fed induction generator, thereby allowing them to keep on producing while the speed varies over a wide range. This enhancement forces the monitoring methods to deal with these large variations in speed and torque, since the conditions are seldom if ever stationary. In an original and inexpensive attempt to tackle this issue through angular sampling, this paper proposes to base the surveillance of the line shafting on the instantaneous angular speed variations experienced by the high speed shaft. The unsteady behaviour of these wind turbines is also a difficulty in term of long term diagnostic, since the comparison of successive measurements is usually performed under the same operating conditions. Parametrization of the indicators according to well chosen variables might bring a valuable tool regarding several aspects. A long term experimental study carried over a 2MW wind turbine will be presented as a first application, and will be used to dress an interesting diagnosis on another wind turbine.