台灣電力防衛系統之研究

Abstract

摘 要 本論文提出一基於相量量測單元(PMU)的台灣電力防衛系統，來防止電力系統因一連串的保護電驛跳脫事故而造成電力系統崩潰。 在一個中央電腦控制中心，使用 PMU 監控電力系統中主要的發電機組以及超高壓輸電線，並且提供預測電力系統不穩定與否及防衛策略之演算法，來避免保護電驛的連續跳脫事故而造成的電力系統崩潰。當故障發生時，我們將所有一同搖擺發電機構成同一群，進而簡化成單機無限匯流排系統。並即時估測單機無限匯流排系統的參數，防衛策略是以保護電驛設定限定等面積法則(Relay Setting Limited Equal Area Criteria)來決定其控制行為的執行時機與矯正量的多寡，其中矯正行為包含負載卸載以及發電機跳機，。 此電力防衛系統是以台電系統來做為建構與測試對象，模擬狀況為台電系統在主要的超高壓輸電線有嚴重的事故，並且引起一連串的電驛跳脫時，而導致類似1999年七月二十九日台灣北部及中部大停電情形。電腦模擬結果顯示，若台電公司有此套電力防衛系統，則1999年之729大停電事件將不會發生。

Abstract This dissertation proposes a phasor measurement units (PMUs) based power defense system to prevent power system blackout due to a cascading relay trip events.. The power defense system uses PMU’s to monitor the generators and the major EHV transmission lines of a power system, and apply an instability prediction algorithm for initiating the remedial control actions to avoid a sequence of relay trip events whenever necessary. When a fault happens, the power defense system group the generators swinging coherently and reduce the system to One-Machine-Infinite-Bus (OMIB) system equivalent. Then using real-time phasor measurements estimates the parameters of OMIB. The strategy for determining the timing and amount of remedial control actions is a proposed relay setting limited equal-area criterion for OMIB. The remedial control actions consist of load shedding and generation tripping. The proposed scheme is tested with Taiwan power system, which experienced a severe fault at a major EHV and caused a successive relay trips resulting in system north and center area blackout on July 29,1999(729-event). According to the computer simulation results, if the Taiwan power system had implemented the power defense system then the blackout of 729-event could be avoided.