現今電力市場已朝向自由化發展，由個別電力網路相互連接所形成之電力池，使得市場參與者在電力供需及電價上有著更多選擇。然而，由於網路互連與自由交易使得維持系統運作在規範內複雜度大增。系統操作者透過節點電價得以有效進行監控與協調，評估每項交易對系統所帶來的影響，確保同時兼顧系統穩定度與滿足負載需求。節點電價不但具有決定邊際成本或邊際價格的能力，更能進一步利用在壅塞管理上。
由於自由交易的特性使得用電需求瞬息萬變，故節點電價的運算必需相當快速以便即時反應。本論文基於潮流分配因子，提出一種相當直觀且易於運用的方法，主要貢獻如下：
一、使節點電價之計算可兼顧運算速度與準確度。其運算時間僅稍長於最佳直流潮流；而其精確度遠高於最佳直流潮流，近似最佳交流潮流。
二、證明在最佳潮流問題中，傳統的各節點功率平衡方程式可以簡化成系統總功率平衡方程式，計算結果不變。由於限制條件大幅減少，使得建構最佳潮流問題及計算節點電價更為容易。
三、透過潮流分配因子，可快速估算出損失因子；透過系統總功率平衡方程式則可求出參考發電成本。故而得以一併算出節點電價中的參考發電成本、電力損失成本及壅塞成本。
因此，利用基於潮流分配因子之最佳潮流，便能快速進行調度與計算節點電價，達到維持系統穩定及儘可能滿足所有負載的目標。

關鍵詞：潮流分配因子、電力損失、節點電價、最佳潮流調度。

Nodal prices, or locational marginal prices (LMP), originates from the optimal power flow (OPF), are a key instrument in the restructuring of electricity. These nodal price signals can reflect the differential value of generation and consumption at each location arising from physical characteristics of electricity networks, namely the existence of losses and capacity constraints. They do also provide a measure for consumption and generation congestion management, both in the short and in the long run.
Inspired by recent developments of power flow congestion distributed factors (CDF), we will re-examine the optimal power flow in terms of these distribution factors. The main contributions of this thesis can be summarized as follows:
1. We propose a fast method for calculating nodal prices of a power network. Its speed is compatible with the DC-OPF while the accuracy is compatible with the standard AC-OPF.
2. Instead of using the real power balanced equations at each node as the equality constraints in the standard OPF formulation, we use the total real power balance equations in the OPF formulation. As the number of equality constraints are significantly reduced, the computation time will also decrease.
3. Since the total system losses can be expressed in terms of CDFs, nodal prices, generation costs, loss cost, and congestion costs can also be easily obtained.
Simulations on two IEEE Test systems have been performed to demonstrate the accuracy of the proposed method.

Keywords : Optimal Power Flow, Nodal Prices, Power Flow Congestion Distributed Factors, Power Losses

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