No abstract

No abstract

No abstract

A three-mass mechanical model that considers both shaft and blade flexibilities was used for the design of a torsional damper to damp drive-train vibrations in a wind turbine. Two torsional dampers were designed: one considering only the drive-train mode and another considering both the drive-train and blade in-plane symmetrical modes. The dampers performance was tested on a simple wind turbine model in Simulink® and then implemented in a more complete model in GH Bladed®. The simulation results on both wind turbine models correlate very well. This result indicates that a three-mass model is a good model for representing the shaft and blade flexibilities for designing a torsional damper. Simulation results show that considering both drive-train and blade in-plane mode frequencies when designing the torsional damper can lead to a better performance in damping torsional vibrations.

Alleviation of excess fatigue loads due to vibrations in the drive-train of wind turbines can be achieved through the use of torsional vibration dampers. Two torsional dampers based on different design approaches were designed and assessed: the first employs a conventional band-pass filter technique, whereas the second involves an alternative model-based approach. Frequency domain analyses were carried out on the system with the two dampers for the cases with and without model uncertainty. The system using the band-pass filter-based damper showed deterioration in stability and performance when subjected to uncertainty in the model and had to be re-tuned to recover a good damping performance. Conversely, the system employing the model-based damper maintained good stability and superior damping performance in the presence of model uncertainties. These attributes can ensure that the damper exhibits a good performance even if the wind turbine parameters vary during operation, such as when ice forms on the blades. Time domain simulations were carried out to verify the frequency domain analyses.

No abstract

No abstract

With a high penetration of wind turbines, the proportion of synchronous generation in the power system will be reduced at times, thus creating operating difficulties especially during frequency events. Therefore, it is anticipated that many grid operators will demand inertia response from wind turbines. In this article, different ways for emulating inertia response in full-rated power converter-based wind turbines equipped with permanent magnet synchronous generators are considered. Supplementary control signals are added to the controller of the wind turbine to extract stored energy from the rotating mass and DC-link capacitors. Simulations in MATLAB/Simulink show that the inertia response is improved by adding a term proportional to the rate of change of frequency and by extracting the stored energy in the DC-link capacitors.