當併入電力系統的風場容量越趨增加時，對於風力發電機的併聯規範也越來越嚴格，若系統發生短路故障而造成風機因低電壓而跳脫，會造成系統的發電量與用電量不平衡，則可能導致電力系統的不穩定。本論文比較了五種不同的低電壓忍受能力改善方法對風機低電壓忍受能力的影響，第一種是以增加轉子阻抗，第二種是使用截波器，第三種是使用消弧電路，第四種是綜合以上方法同時使用，第五種為利用市電側轉換器做電壓提升的功用。本論文使用Digsilent 模擬軟體來建立風力發電機與市電併聯的模組，模擬中所使用的風機類型為具pitch control 控制的雙饋式感應發電機。本研究在不同的風機輸出端電壓與持續時間下，比較四種方法對風機低電壓忍受能力的改善情況。模擬結果顯示，並用這些改善裝置方法最能夠讓風機度過低電壓的狀態。

Since large scale unscheduled tripping of wind power generation could lead to power system stability problem. Thus network interconnection regulations become more rigid when the wind power penetration reaches a non-neglible portion of the total power generation. This thesis presents a comparison of five different low voltage ride through (LVRT) capability enhancement technologies, i.e., additional rotor resistance, DC bus chopper, crowbar on rotor, the combination of above schemes, and grid voltage support by controlling grid side converter. System simulations are performed under Digsilent environment with model and control blocks provided by
the package. Additional models are developed to implement the LVRT enhancement schemes studied. A Doubly-Fed Induction Generator (DFIG) with pitch control is used to simulate different system fault scenarios with different voltage sag magnitude and duration time. Simulation results indicate that different enhancement schemes provide various levels in relieving DC bus overvoltage, rotor winding overcurrent, and overspeed problems, and the method combines all tested schemes seems to provide the best result.

目錄
摘要..................................................... I
Abstract ................................................ II
目錄................................................... III
圖目錄................................................... V
表目錄................................................ VIII

第一章 緒論 ............................................ 1
1.1 研究動機與目的....................................... 1
1.2 風力發電現況簡介..................................... 2
1.3 風力發電機架構簡介................................... 4
1.4 各國之電力系統併聯準則對LVRT 及無效功率的規定........ 7
1.5 風力發電機對系統故障之忍受能力相關研究.............. 11
1.6 論文架構............................................ 12
第二章 雙饋式感應發電系統之模型建構......................... 13
2.1 雙饋式感應發電機基本原理............................ 13
2.2 雙饋式感應發電機之動態模型.......................... 13
2.3 風渦輪機的數學模型.................................. 19
2.4 最大功率追蹤........................................ 22
2.5 扇葉角度控制器...................................... 23
2.6 雙饋式感應發電機控制架構............................ 25
第三章 雙饋式感應發電機低電壓忍受能力的改善方法............. 31
3.1 雙饋式感應發電機基本控制原理及故障時的運轉情況...... 31
3.1.1 基本控制原理............................... 31
3.1.2 雙饋式感應發電機故障動態情況............... 33
3.2 提高轉子電阻之改善原理.............................. 35
3.3 使用DC-chopper 之改善原理........................... 35
3.4 增加 Crowbar 保護裝置之改善原理...................... 37
3.5 轉子阻抗、截波器、Crowbar 並用...................... 38
3.6 以市電側轉換器提供虛功之低電壓忍受能力改善原理...... 39
第四章 動態模擬結果與比較................................... 41
4.1 模擬基本架構介紹.................................... 41
4.2 鼠籠式感應發電機與雙饋式感應發電機低電壓忍受能力模擬比較 ............................................. 43
4.3 運用電壓忍受能力改善策略的發電機動態響應比較........ 45
4.3.1 雙饋式感應發電機低電壓動態響應............. 45
4.3.2 增加轉子電阻模擬........................... 48
4.3.3 DC-chopper 應用模擬........................ 52
4.3.4 消弧電路Crowbar 應用模擬................... 54
4.3.5 轉子電阻、截波器、Crowbar 並用模擬......... 57
4.3.6 以市電側轉換器提供虛功之改善方法模擬....... 59
4.4 模擬結果分析與討論.................................. 61
第五章 結論與未來建議....................................... 69
5.1 結論 ............................................. 69
5.2 未來研究方向........................................ 70
附錄一 台灣電力公司之電力系統併聯準則................... 71
附錄二 發電機內部參數與線路參數表....................... 76
參考文獻................................................ 77

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