雙饋式感應風力發電機之模糊控制器設計

Design of Fuzzy Controllers for Doubly Fed Induction Generators

郭秉勳(Ping-Hsun Kuo)

指導教授 ： 許源浴

國立臺灣大學/電機資訊學院/電機工程學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201601768

摘要

本論文將功率控制模式結合模糊控制器應用於雙饋式感應發電機的轉子側變流器，此方法在故障期間可以控制風機輸出至電網的實虛功，同時降低過電流。雙饋式感應發電機在穩態期間操作在最大功率追蹤模式下，而故障發生時為了輸出最大的功率，發電機持續操作在最大功率追蹤模式下，然而此操作模式會有過電流的問題發生。
本文利用理論分析推導出雙饋式感應發電機的數學模型，並且利用此模型設計出模糊控制器的參數，使設計出來的模糊控制器兼顧響應速度和系統穩定。此外，模糊控制器採用的功率控制模式，能讓雙饋式感應發電機在故障期間除了輸出實功以外，還能輸出虛功來提升系統端電壓。
模擬方面使用Matlab/Simulink®軟體來建立併網的雙饋式感應發電機模型，並評估轉子側變流器模糊控制器的效果。從模擬結果觀察到故障期間模糊控制器擁有較好的動態響應以及對發電機參數變動有良好的強健性，因此可以抑制故障暫態電流。而發電機操作在功率控制模式之下則能夠降低故障穩態電流。所以故障時採用模糊控制器和功率控制模式能夠保護轉子側變流器，並提升風機低電壓穿越能力。

關鍵字

風力發電 ； 雙饋式感應發電機 ； 最大功率追蹤 ； 功率控制模式 ； 模糊控制器 ； 轉子電流

並列摘要

This thesis presents power mode control strategy with a Fuzzy proportional-integral(PI) controller in the rotor side converter of the doubly fed induction generator (DFIG). The proposed technique is employed to control the active and reactive power of wind turbine to the grid and reduces the overcurrent during the grid fault. The DFIG is operated at maximum power tracking mode in the steady state, and keeps operating at this mode to deliver power as much as possible during fault. However, it causes overcurrent problem in this operation.
In this work, the mathematical model of the power controller is developed by theoretical analysis for DFIG and employed to determine proper gain for the Fuzzy PI controller such that DFIG has fast response and good stability. Moreover, DFIG under power mode control delivers not only active power but also reactive power to boost the system voltage.
The MATLAB/Simulink® software is employed to develop the grid-connected DFIG model and evaluate the effectiveness of Fuzzy PI controller. The simulation results show that the Fuzzy PI controller enhances the dynamic performance and the rotor transient overcurrent can be suppressed during fault initiation. Moreover, DFIG under power mode control is able to decrease the steady-state rotor current during faulted period. Therefore, the rotor side converter can be protected by employing the Fuzzy PI controller for the DFIG operated under power control mode during the fault. Low voltage ride through capability of the DFIG can be enhanced by the proposed fuzzy PI controller.

並列關鍵字

wind power generation ； doubly fed induction generator ； maximum power tracking ； fuzzy controller ； rotor current

參考文獻

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