Dissertation
Dissertation > Industrial Technology > Electrotechnical > Power generation, power plants > Variety of power generation > Wind power

The Research of Large Scale Variable Speed Adjusted Pitch Wind Turbine Flexible Coordinate Control Technology

Author XingZuoXia
Tutor ZhengQiongLin;YaoXingJia
School Beijing Jiaotong University
Course Proceedings of the
Keywords Wind turbine Wind turbine Control Flexible Coordination Doubly Fed Induction Variable-speed pitch Torque Control Pitch control Modal linearization Expert Decision System PID Damping filter Vibration Control Constant Frequency Speed ??Control Adaptive Direct Torque Control Hydraulic pitch BP neural network
CLC TM614
Type PhD thesis
Year 2008
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In this thesis, the general operation control technology of current main stream type --Doubly fed variable speed adjusted pitch wind turbine was researched. The "flexible coordinate control" concept was proposed in general wind trubine operating control strategy. The "flexible control" research was developed in torque, pitch and power output control. For optimal wind turbine operating performance, the necessary "coordinate conrol" between controller units was proposed and deep researched. The "flexible" denotes making turbine quick track demanded signal, deduceing load impact, deducing vibration, smoothening output power. The "coordinate" denotes each controller can be coordinately planned and optimal performance is reached according to control objects in different stages.On the torque control, pitch control and general coordinate control strategy of variable speed pitch adjustable wind turbine, the control object was found on the base of modal linearization method, among which the mechanical dynamic response was considered. After 3 operation ranges according to wind speed were divided, based on the modal linearization control object, the region 2’ optimal tip-speed control was researched, and the simplicity parameters optimal method was introduced into flexible PID torque control. Based on the research of region 3’ pitch control, the general machine coordinate control strategy based on expert decision system was proposed and described, and the trial contrast analyse was processed.On the vibration problem of variable speed wind turbine, especially the drive train torsion vibration and rotor-tower coupling vibration problems, the Campell drawing method was used in wind turbine couping vibration analyse. Based on this analyse, the method of damping filter restraining vibration and deducing load flexible control stategy was proposed. It was also proposed that the tower aft-fro first order modal frequency damping filter was added in PID controller to restrain tower vibration. At the same time, in the torque control over rated wind speed region, the rotor inner plain first order modal damping frequency filter was added to torque control to restrain drive train vibration. The Blade software simulation and prototype on-line condition minitoring were used to verify the control performance.On the flexible power output control of doubly fed variable speed wind turbine, the system model including drive train wind resource, wind consumption model, mechanical transmission chacteristic, generation system , pitch and speed control etc was founded, and the simulation and experiment were processed. Based on this mathematic model, the adaptive direct torque control strategy was researched and the whole machine operating power output characteristic was simulated. On the 30kW trial platform, the experiment of connecting to the grid was conducted and power output performance was analyzed. The grid faults such as voltage dip response during normal operation were simulated and forecasted, and the control strategy was contrast and analyzed.About the large inertia, parameter non-linear, time changing characteristic problems in hydraulic driven pitch system, the BP Neural Network PID flexible control strategy was proposed. By contrasting and analyzing the results of experiments on Matlab simulation and SUT-1000 wind turbine, the algorithm was verified to have good tracking performance.

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