Research On Combined Simulation And Control Of Wind Turbine At Constant Power Stage

Wind energy has been rapidly commercialized in recent years as a clean,safe and renewable energy source.Wind turbines are usually installed on the sea or on mountains in remote areas.Poor working conditions and the randomness of wind will affect the quality of output power.Therefore,to study wind power system modeling methods in depth,to establish reasonably and accurate model,and to introduce an advanced control theory on the model for control strategy designing are of great significance to improve the generation quality of wind turbines.The project is supported by the National Natural Science Foundation of China,"Analysis of failure mechanisms and fault diagnostics under eccentric error for doubly fed induction generator(DFIG)wind turbines(NSFC Grant NO.51577008)".Regarding 1.5MW DFWT in a factory as study object,each part of the unit has been built.Then combined simulation technology is used to establish the mechanical and electrical combined simulation model of the unit.Based on this model,the constant power control strategy is studied,which is established to lay the foundation for the follow-up fault signal extract and diagnosis of misalignment under the condition of high wind speed.The following contents are included:Firstly,the structure of DFWT transmission system is analyzed.The 3D modeling and assembly body installing of gear box,coupling and generator are carried out by Solid Works.The constraints and drive parameters are added to the 3D model after it is imported to Adams so that the virtual prototyping model can be built.Dynamic simulation is carried out by Adams and the correctness of the model is verified.Secondly,the model of wind turbine and its control system as well as DFIG and its control system are built by MATLAB/Simulink software.Specifically including wind speed,wind turbine,pitch actuator,DFIG and back to back PWM converters.Then,the operating characteristics of the DFWT are analyzed and the control strategy of constant power operation stage is clarified.Then a design method of combined simulation platform based on virtual prototyping technology is proposed.Controlling widget Adams/Controls is used to connect mechanical system of transmission chain and control system of the unit,forming a closed loop between Adams and MATLAB/Simulink to get data exchanged through state variables.The establishment of the combined simulation model of the DFWT is completed.In the end,based on the combined simulation model and operational characteristics analysis of the unit,composite pitch controller of fuzzy feedforward and fuzzy adaptive PI control is designed.The parameter tuning difficulties of traditional PI controller is solved and the power fluctuation caused by wind disturbance is compensated in time.The constant power control of the unit above the rated wind speed is realized.