利用閘控串聯電阻改善雙饋式感應發電機之故障穿越能力

Fault Ride-Through Improvement of DFIG Using GTO-thyristor Controlled Series Resistor

翁啟維(Chi-Wei Weng)

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(2015年)

https://doi.org/10.6342/NTU.2015.01412

摘要

本論文主要目的在於研究與電力系統併聯之雙饋式感應發電機之動態特性。當發電機操作在最大功率追蹤模式下，探討故障發生時，轉子電流的過電流問題，和定子端電壓的低電壓問題，使發電機在故障時依然可以穩定的操作於最大功率追蹤模式下。
本文利用閘控串聯電阻(GCSR)補償在轉子側，可以抑制在故障時的轉子暫態電流；補償在定子側，可以提升定子端電壓和降低轉子穩態電流至額定電流之下。此外，本文針對發電機在不同風速及故障電壓等級下，找出同時符合電流規範和發電機穩定運轉的可行區間。
本論文以MATLAB/Simulink/SimPowerSystems軟體進行模擬，建立併網之雙饋式感應發電機模型，模擬結果顯示，當系統發生故障時，閘控串聯電阻可提升發電機的定子端電壓，並使轉子電流的暫態電流小於1.5標么和穩態電流小於1標么，保護轉子側變流器並提升風機低電壓持續運轉能力。

關鍵字

風力發電 ； 故障穿越 ； 雙饋式感應發電機 ； 閘控串聯電阻 ； 轉子電流 ； 最大功率追蹤

並列摘要

Dynamic performance of a doubly-fed induction generator (DFIG) connected to a power system is investigated in this thesis. The overcurrent in the rotor side and the generator voltage dip in the stator side are studied. In order for the generator to be operated stably during the faulted period, an effective approach must be developed.
In this thesis, GTO-thyristor Controlled Series Resistor (GCSR) is proposed to reduce the transient rotor current in the rotor side and increase the stator voltage and reduce the steady-state rotor current during the faulted period. Moreover, in order for the DFIG to be operated under different wind speeds and under different fault voltages, feasible regions for the generator to be operated stably without overcurrent are determined.
The MATLAB/Simulink/SimPowerSystems simulation software is used to simulate the dynamic performance of the grid-connected DFIG. Simulation results indicate that the stator voltage can be enhanced by the proposed GCSR at the stator. Moreover, steady-state rotor current can be reduced to be less than 1 p.u. and transient rotor current can be reduced to be less than 1.5 p.u. . Thus, the rotor side converter can be protected and the DFIG can be operated stably during faulted period.

並列關鍵字

wind power generation ； fault ride-through ； doubly-fed induction generator ； GTO-thyristor Controlled Series Resistor ； rotor current ； maximum power tracking

參考文獻

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