雙饋式感應風力發電機之小訊號穩定度分析

Abstract

本論文主要之目的在於分析雙饋式感應風力發電機在最大功率追蹤之小訊號穩定度，其分析方法包括頻域分析法、時域模擬法及Prony法。 在頻域分析方面，根據雙饋式感應風力發電機之狀態方程式(state equation)且利用MATLABR/SIMULINK軟體計算平衡點及線性化模型後，求得狀態矩陣之特徵值來評估小訊號穩定度。 在時域模擬方面，在MATLABR/SIMULINK中建立雙饋式感應風力發電機之數學模型，並且在系統加入擾動後，觀測其輸出響應並評估小訊號穩定度。 在Prony法方面，利用數位訊號處理之概念，分析雙饋式感應風力發電機系統之輸出響應圖以獲得特徵值。 將上述三種分析方法分別應用在完整模型之發電機模型、忽略磁通暫態之發電機模型、長輸電線及短輸電線等四種案例中，結果顯示不同之分析方法可獲得一致的結果。

The goal of this thesis is to analyze the small signal stability of a double fed induction generator (DFIG) equipped wind turbine under maximum power tracking using the frequency domain analysis method, time domain simulation method, and the Prony method. In the frequency domain analysis method, the steady state operating point and linearized model were first searched by MATLABR/SIMULINK software. Then the eigenvalues were computed for small signal stability analysis. In the time domain simulation method, the mathematical model of DFIG was created by MATLABR/SIMULINK software for time domain simulation. Dynamic response curves for the system subject to disturbance were employed to evaluate small signal stability. In the Prony method, the eigenvalues were computed from the time domain response curves based on the concepts from digital signal processing. Based on the results for four different cases include full generator model, reduced-order generator model neglecting stator transients, transmission line of short length, and transmission line of long length, it is concluded that the three methods give consistent results for small signal stability.