使用差分近似演算法進行風力發電系統孤島效應偵測

Islanding Detection for Wind Power Generating System using Finite Difference Approximation

莊錦俊(Chin-Chun Chuang)

指導教授 ： 洪穎怡

中原大學/工學院/電機工程研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700700

摘要

近年來國家大力推行風力及太陽光電發電等分散型電源，其所發的電能均饋入公共電力網路。當再生能源發電設備與電力系統併聯運轉供電時，若市電因故斷電進而停止對區域負載供電，而分散式發電設備未即時檢知並切離市電系統，其仍然持續對此區域負載供電，最終形成「孤島運轉現象」。此將危害到市電網路維修人員發生觸電事件以及相較對電力有靈敏度的電子設備易造成損害，且配電系統保護電驛容易產生誤動作。
一般孤島運轉現象的偵測技術區分為兩類，第一類為被動式偵測法，第二類為主動式偵測法，但經由參考文獻得知對於不同特定負載仍存在「無法偵測區域」。本文運用Matlab/Simulink軟體模擬風力發電系統併接市電的情況，包括建構向量突波電驛與頻率變化電驛，並且試驗於併聯運轉與孤島運轉效應之偵測，且使用差分近似演算法對於風力發電系統孤島效應其所產生的非偵測區域作擾動偵測。最後對於無法偵測區域、孤島現象偵測時間進行評估與統計作分析。

關鍵字

孤島運轉現象 ； 風力發電系統 ； 被動式偵測法 ； 主動式偵測法 ； 差分近似演算法 ； 無法偵測區域

並列摘要

Nowadays, Distributed Generation Systems (DGSs), such as wind power and solar power and so on, are extensively installed in Taiwan. The generated electricity is fed into the utility electrical network. The power system will be operated and generate electricity disjointed with the electrical facilities of renewable energy, if the utility power is in a forced outage and results in stopping supplying power to the local load. Besides, if the electrical facilities of the DGSs don’t detect this condition immediately and separate from the utility power system, then it will still feed the power to local loads and it will become an Islanding Event. That will be most likely to hurt maintenance workers of the utility and cause electric shock events. Moreover, islanding operation will also cause electricity-sensitive facilities to be damaged and lead to malfunction in protect relays in the distribution system.

Generally speaking, the detection techniques for the islanding event are divided into two groups. The first one is active detection method and the second one is passive detection method; however, there still exist non-detection zones for the passive detection method. The thesis applies Matlab/Simulink software to simulate the situations of wind-generation-system (WGS) in parallel with the utility. That includes vector surge relay (VSR) and rate-of-change-of frequency (ROCOF). This thesis proposed a method based on finite difference approximation to reduce the non-detection zone which is defined with islanding effect of the WGS. The detection time and disturbed reactive power are estimated for detecting islanding.

並列關鍵字

Islanding event ； non-detection zone ； finite difference approximation ； active detection method ； Wind-turbine generator system ； passive detection method

參考文獻

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