以動態電壓調整器改善市電併聯之鼠籠式感應發電機低電壓穿越能力之研究

LVRT Capability Improvement of a Grid-Connected Squirrel Cage Induction Generator by DVR

莊一麟(Yi-Lin Chuang)

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(2013年)

https://doi.org/10.6342/NTU.2013.10970

摘要

隨著風力發電機組總裝置容量的增加，世界各國紛紛制定新的風機併網規範，因應風力發電機組與電力系統互聯可能產生的問題；其中，與此併網問題密切相關的法規，乃風機之低電壓穿越能力，要求風機在擾動發生時能夠維持併網，並支持電網直到電壓恢復。
由於鼠籠式感應發電機構造簡單、可靠性高、維修成本較低，故廣泛被應用於風力發電機組，但是當系統發生故障時，其端電壓容易急遽下降，造成電磁轉矩衰減使發電機無法輸出電功率，由於故障期間發電機吸收機械功率大於輸出之電功率，將使轉子轉速不斷增加，導致過速保護啟動使之與市電解聯。為了使風機能在系統故障期間持續併網運轉，本論文利用動態電壓調整器，在系統發生短路故障時，穩定鼠籠式感應發電機之端電壓，使發電機可穩定輸出功率，避免轉子過速而與市電解聯。
本論文以MATLAB/Simulink/SimPowerSystems軟體，建立併網之鼠籠式感應發電機模型，模擬結果顯示，當系統發生三相短路故障時，動態電壓調整器可穩定鼠籠式感應發電機端電壓，確保發電機在系統故障期間穩定輸出電力，並能持續併網運轉，符合台電再生能源發電系統併聯技術要點中，風機低電壓持續運轉能力之規範。

關鍵字

風力發電 ； 低電壓穿越 ； 感應發電機 ； 動態電壓調整器

並列摘要

The increasing wind farm installations have forced utilities worldwide to develop new grid codes to integrate wind power generation into the grid. One of the highly related codes is the low voltage ride through (LVRT) capability of wind generators, which requests that wind turbines remain grid-connected and help support the system voltage following disturbances.
Squirrel-cage induction generators (SCIGs) have been extensively used in wind power generation due to their simple configuration, reliability, and low maintenance cost compared to other types of wind generators. However, when a fault takes place in the power system, its terminal voltage tends to dip dramatically, which leads to the decrease in SCIG’s output electric torque and thus hinders SCIG from generating electric power. Since the real power exported to the grid is significantly reduced during the fault while the input mechanical power from the wind turbine remains almost constant, the generator will accelerate during the short circuit event to mechanically store the energy excess. As the generator speed rises to a certain limit, over-speed protection will be triggered to disconnect the wind turbine from the grid to protect it from being damaged. In this thesis, a dynamic voltage regulator (DVR) is designed to regulate the terminal voltage of a SCIG during system fault so that SCIG has a stable real power output. Since the generator speed is stable, grid connection of the wind turbine during system fault can be ensured.
This thesis uses MATLAB/Simulink/SimPowerSystems simulation tool to simulate the dynamic performance of a grid-connected SCIG. Simulation results indicate that SCIG compensated by the proposed DVR has a regulated terminal voltage and exports steady real power when there is a three-phase fault. Through computer simulations, it is convinced that the SCIG with DVR is able to remain connected to the grid during system fault and the LVRT requirement imposed by Taiwan Power Company can therefore be met.

並列關鍵字

wind power generation ； low voltage ride through ； induction generator ； dynamic voltage regulator

參考文獻

[5]張家閔, “動態電壓調整器應用在穩定併聯於市電之感應發電機端電壓之研究,”臺灣大學電機所碩士論文, 2012.

[16]黃維綱, “用於與市電併聯感應發電機調整之動態電壓調整器設計,” 臺灣大學電機所碩士論文, 2011.

[17]陳翔琮, “鼠籠式風力發電機串聯動態電壓調整器之設計,” 臺灣大學電機所碩士論文, 2010.

[19]辛偉綸, “用於感應發電機互聯電力系統靜態同步補償器之設計,” 台灣大學電機所碩士論文，2006.

[21]梁國堂, “靜態同步補償器控制器參數之設計,” 臺灣大學電機所碩士論文, 2008