創新小型風力發電機葉片變旋角控制系統設計與發電機轉子定轉速控制之研究

Abstract

小型風力發電機由於成本考量與可改裝空間較少之故，大部分都採用無控制或失速控制方式，但因為無法擷取額定風速以上的風能，在發電效率上尚有改進空間，本文旨在發展主動控制2kW小型風力發電機組的設計及實驗原型系統，以改善小型風力發電機的發電性能。 本文以東元2kW被動式小風機為基礎，首先發展創新機構葉片變旋角機構及主動式變旋角控制系統，利用直流伺服馬達驅動葉片傘形齒輪機構，並搭配PID旋角控制器，以一傘齒輪帶動三個從動傘齒輪，改變風機葉片旋角。其次建立小風機的全機系統數學模型，並以FAST、ADAMS與MATLAB軟體模擬小風機的全機性能，並發展葉片變旋角控制器及發電機轉子定轉速控制器，並先以模擬驗證創新葉片變旋角定位系統與發電機轉子定轉速控制系統。 實驗原型系統以東元2kW被動式小風機進行機構及控制系統改裝，以PID控制及模糊滑動平面控制的閉迴路控制，包括葉片的變旋角(pitch angle)控制與發電機的轉子定轉速控制，並於開放式風洞進行實測，實現2kW小型風力發電機在額定風速之上時，利用直流伺服馬達的傘齒輪帶動三個從動傘齒輪，改變風機葉片旋角，並調整葉片的旋角使風機維持在額定轉速，保持額定功率的輸出，實現2kW小型風力發電機的主動控制。

Most of the small wind turbines are designed with no control or passive control due to the cost consideration so that the electric generation performance is limited as the wind speed is over the rated wind speed. Thus, the objective of the paper is to improve the electric generation performance by developing a novel active pitch control system and a rotor constant rotational speed control for a 2kW small wind turbine. The study first developed a novel mechanism design for the active-controlled pitch control system. The novel mechanism is the DC servo motor-driving variable-pitch bevel mechanism. By using the PID controller, the one to three bevel gear chain driven by DC servo motor is applied to adjust the pitch angles of the three blades at the same time. Then, the dynamic simulation of the overall system of wind turbine was developed by combining softwares of FAST, ADAMS and MATLAB. After that, the proposed novel mechanism design of the active pitch control and the constant rotational speed control of rotor could be verified via dynamic simulation. For that, the controllers of pitch control and the constant rotor constant rotational speed control were developed by PID control and fuzzy sliding mode control. The experimental prototype system was modified according to the TECO 2kW small wind turbine which original type has no control. The novel mechanism for the active pitch control system and the required controller system were integrated and tested in the open wind tunnel. When the wind speed is above the rated wind speed, the DC servo motor-driving variable-pitch control system starts to work to regulate the pitch angle to keep the constant rotational speed of rotor. The one to three bevel gear chain driven by DC servo motor is applied to adjust the pitch angles of the three blades at the same time. Through the active pitch control system, the constant rotational speed control of rotor can be implemented.