基于低成本單片機(jī)的相量測(cè)量單元提高智能電網(wǎng)可靠性

　　8月14日，安大略和美國(guó)東北部八個(gè)國(guó)家的2003， 50萬(wàn)人失去了電力。一個(gè)炎熱的下午和克利夫蘭附近一座燃煤發(fā)電站意外的破裂，引發(fā)了連鎖反應(yīng)，在94分鐘內(nèi)，美國(guó)東北部大部分地區(qū)都陷入了黑暗之中。花了24個(gè)多小時(shí)才恢復(fù)了電網(wǎng)大部分地區(qū)的電力，完全恢復(fù)了滿足該地區(qū)需求的生產(chǎn)能力，幾乎花了兩周時(shí)間。它將永遠(yuǎn)被銘記為2003的大停電。

　　令大多數(shù)電網(wǎng)運(yùn)營(yíng)商吃驚的是，一場(chǎng)看似無(wú)辜的事件可能會(huì)導(dǎo)致整個(gè)電網(wǎng)崩潰。當(dāng)輸電線路接近最大容量時(shí)，克利夫蘭的一個(gè)局勢(shì)被允許超過(guò)90分鐘未被發(fā)現(xiàn)。炎熱的夏季空氣對(duì)該地區(qū)的空調(diào)產(chǎn)生了巨大的電能需求。當(dāng)燃煤發(fā)電站脫機(jī)時(shí)，當(dāng)?shù)剌旊娋€路超載，導(dǎo)致線路延伸并向地面下沉。當(dāng)線路接觸到允許在傳輸線下面生長(zhǎng)的樹(shù)時(shí)，線路短路到地面，導(dǎo)致自動(dòng)電路保護(hù)中斷。這就給剩余的線帶來(lái)了更多的壓力。一個(gè)小時(shí)后，其他三條線路失靈，俄亥俄電力公司的剩余電力線路也出現(xiàn)了災(zāi)難性的浪涌，引發(fā)了其他幾條線路斷路器。由于剩余的輸電線路沒(méi)有足夠的能力攜帶整個(gè)區(qū)域所需的能量，整個(gè)電網(wǎng)在90秒內(nèi)倒塌。這家電廠關(guān)閉了。由于無(wú)法提供所產(chǎn)生的能源，一些核電站被迫執(zhí)行緊急程序，關(guān)閉核反應(yīng)堆。這是一個(gè)對(duì)核反應(yīng)堆造成損害的程序。在電網(wǎng)上恢復(fù)電力幾乎花了四天時(shí)間，近兩周時(shí)間才使所有反應(yīng)堆恢復(fù)滿負(fù)荷運(yùn)轉(zhuǎn)。

　　An investigation of The Great Blackout revealed that the power grid control systems were antiquated and largely unable to monitor and protect the health of the grid. Time was never an issue. It took 31 minutes from the moment the Cleveland power station failed until the first transmission line collapsed. The situation looked manageable for another 61 minutes， until more transmission lines started burning out. The men and women controlling the grid were caught completely off guard because they had no means to detect warning signals from the power grid. Without access to real time information， the power grid control rooms were unable to predict where the next error would occur and plan corrective actions. The investigation concluded that the disaster could have been avoided if the power grid had been equipped with better monitoring systems. The U.S. Department of Energy considers the US-Canada blackout in 2003 to be the single most important motivator behind the Smart Grid initiative.