Research On Dfig Wind Turbines Software Simulation System And Control Method

As the wind power developing rapidly, a series of wind turbine simulationsoftware have been developed, FAST is one of them. Due to the characteristics ofopen source code and free download, FAST is suited for academic research.However FAST itself does not have the ability to process data and draw picture, andits code operation mode is not conducive to design controller intuitively, whileMatlab has obvious advantages in this regard. For these reason, we use FAST andMatlab co-simulation to design controller in this thesis.Wind turbine running process is divided into three regions according to windspeed range, wind speed is very large in the third region, it need use collective pitchcontrol to limit the output power, in order to protect the motor. Because thesensitivity of the turbine power to pitch angle is quite different with different windspeed in this region, so fixed parameter PI control can not achieve the goal oflimiting output power by collective controller. This thesis is based on the equationsof motion of the wind turbine drivetrain derived a formula to calculate PI parametersaccording to the pitch angle, applied PI gain scheduling method to achieve thecollective pitch control, limited output power, and got good performance insimulation.With the wind turbine catacity increase, the size of blades is also growing,which make the influence of vibration fatigue loads on the blade life be moresignificant. This thesis use Coleman coordinate transformation method to convertthe blade root bending moment information from the rotating coordinate system tothe fixed coordinate system, then control them separately, and convert the controlsignals to a pitch angle of the three blades separately, and then plus the pitch anglefrom collective pitch controller, achieve independent pitch for vibration dampingcontrol. Simulation results in different wind speed show that the vibration dampingeffect in a steady wind is more than80%, and the effect in a turbulent wind is50%.Analysis the simulation results, we found that the Coleman coordinatetransformation is essentially to pitch the blade cyclic, to compensate for theaerodynamic imbalance, to achieve the effect of vibration damping.