因應我國系統再生能源高佔比之實功升降載率結合輔助服務分析

Abstract

隨著當前風光發電逐年提高，其出力間歇特性對系統產生衝擊，為維持電網安全需透過嚴格之再生能源併聯技術要點加以限制。當前我國針對再生能源實功升降載率規範中尚未限制實功降載率也未包含太陽能案場及陸域型風場，然而風光總量年年攀升，2050年淨零碳排再生能源發電占比可能高達60-70%，若針對其出力瞬間變化無完好之配套措施，將對系統造成巨大影響，本研究統整並比較多國再生能源併網法規，提出我國實功升降載率規範問題及需改進之處。 針對實功升降載率限制，本研究首先利用PSS®E建置系統並執行不同實功升降載率下之敏感度分析；接著利用MATLAB建構一最佳化數學模型同時結合離散非線性最小平方法及混合整數平方規劃法，基於最小化各類輔助服務成本下，進行再生能源發電之暫態穩定度分析並取得最佳化資源需求量，結果顯示不僅能得出最適當之再生能源升降載限制大小，亦能取得整體最小成本並兼顧電力系統穩定性。 配合國際趨勢及能源轉型，在大量再生能源廣泛接納的同時，須思考如何使其最大效益且安全發電，本研究透過實際系統模擬得出之結果，可做為未來我國針對再生能源實功升降載率法規修訂之參考。

With the increasing penetration of renewable energy, its intermittent characteristics have significantly impacted the power system. To maintain grid safety, strict grid codes for renewable energy must be enforced. Currently, Taiwanese grid code on the active power ramp rate for renewable energy does not restrict the ramp-down rate and excludes PV plants and onshore wind farms. By 2050, renewable energy could account for 60-70% of electricity, aiming for Net Zero Emissions. The lack of comprehensive measures for their instantaneous output changes will significantly affect power system frequency. This study will compile and compare the grid code from various countries, identify issues in our country's active power ramp rate limit, and suggest improvements. To address limitations on active power ramp rates, first, use PSS®E to build a power system and perform sensitivity analyses under different ramp rates. Second, use MATLAB to construct an optimization model combining discrete nonlinear least squares and mixed-integer quadratic programming. Conduct a transient stability analysis and determine optimized resource requirements, minimizing the costs of various ancillary services. The results indicate the most appropriate ramp rate limitations for renewable energy, achieving the lowest cost while maintaining stability. In line with international trends and the energy transition, we must maximize the benefits of renewable energy while ensuring power system safety. The methods and results from this study can guide future amendments to Taiwan's grid code on the active power ramp rate for renewable energy.