大型風力發電機整合模擬與創新液壓變旋角控制實驗系統之研究

Abstract

本文旨在建立風力發電機整合模擬系統，藉由導入風力發電機模擬軟體FAST、多體動力學模擬軟體ADAMS及數值模擬軟體MATLAB/SIMULINK，此模擬系統可以達成全方位及高自由度的建模與動態模擬。FAST負責風力發電機的機組建模和空氣動力計算，ADAMS負責多體動力學的動態模擬，而MATLAB/SIMULINK則負責子系統的建模與控制器的設計。此整合模擬系統依現有大型風力發電機為基礎，建立仿真且高近似度的模型，並參考實際的子系統，包含直流馬達驅動的旋角系統、感應馬達驅動的偏航系統和直驅式的永磁同步發電機。全系統並經與實測資料的交叉比對，其葉片與塔架更經由模態分析來進一步驗證此模型的有效性，並建立起一套完整的控制策略。同時，本論文更提出另一套創新的風力發電機子系統，包含泵控液壓旋角控制系統、液靜壓傳動系統以及雙饋式感應發電機，以達到無段變速的功能。 同時，為了證明此創新想法的可行性，本研究亦根據實際風力發電機葉片規格建立出一個等效的實驗機組，利用交流伺服馬達驅動定排量泵驅動泵控液壓旋角系統。並根據此系統建立非線性控制器來實現軌跡追蹤與強健性控制。此外，利用硬體迴路的概念模擬出風機葉片根部在運轉模擬中會承受的力矩並回授到實驗系統以測試系統的抗干擾能力。硬體迴路的實驗結果證明了此系統的有效性，並且提出了新的干擾力矩模型。其中泵控液壓旋角控制系統結合控制器的設計更經由實驗來驗證與實現，實驗的結果顯示在軌跡追蹤與抗干擾分析皆證明此創新想法的可行性。未來將針對離岸風力發電機建立起相關機組的建模以幫助國內新興綠色能源計畫的推動與發展。

A novel dynamic closed-loop co-simulation methodology of overall wind turbine systems is presented in this thesis. This methodology consists of aerodynamics, mechanism dynamics, control system dynamics, and subsystem dynamics. Aerodynamic and turbine properties were modelled in FAST; ADAMS performed the mechanism dynamics; control system dynamics and subsystem dynamics such as generator, pitch control system and yaw control system were modeled and built in MATLAB/SIMULINK. Thus, this comprehensive integration of methodology expanded both the flexibility and controllability of wind turbine.. Besides, the dynamic simulation results were compared with the measuring results of SCADA (Supervisory Control and Data Acquisition) of a 2MW wind turbine for ensuring the novel dynamic co-simulation methodology. Besides, a novel hydrostatic speed control system with hydraulic pump-controlled pitch system and hydrostatic transmission system was also proposed in this study. To realize the hydrostatic speed-controlled wind turbine, a full-scale test rig of the hydraulic pitch control system of a 2MW wind turbine was developed for practically experimental verification. The pitch controller designed by two degree-of-freedom (2-DOF) motion controller with feedback linearization was developed to enhance the controllability and stability of the pitch control system. The wind turbine simulation software FAST was used to analyze the motion of the blade which results were given to the test rig as the disturbance load command. The robust 2-DOF pitch controller developed in this thesis contained a feedforward controller with feedback linearization theory to overcome the nonlinearities of the system and a feedback controller to improve the system robustness for achieving the disturbance rejection. Consequently, this thesis not only developed the wind turbine co-simulation methodology with high flexibility but also proposed and realized the novel robust hydraulic pitch control system by performing the excellent tracking performance of 5th order polynomial and sinusoidal path trajectory control in the experiments.