電力系統(tǒng)復習課件2005級暫態(tài)

1、電力系統(tǒng)分析Power System Analysis 艾 欣 教授、博士生導師 電力工程系副主任 電子郵件： 辦公室：教五樓C416房間 電話： 80795848 POPO賬號：simonxinai內容提要電網可用輸電能力（ATC）電力系統(tǒng)可視化供電能力的含義充足的供電能力應該包括：充足的電源（裝機容量充足、電源種類構成合理、電源調節(jié)能力強）；合理的電網結構和傳輸能力；適當的電網規(guī)模。供電能力的含義電源的供應能力和電網的供應能力滿足電力的能力滿足電量的能力滿足供電可靠性的能力滿足電能質量的能力滿足長期、短期電力需求的能力滿足電力市場條件下負荷需求的能力有黑啟動，在大停電后具有快速恢復供電的能

2、力。線路的輸送功率極限熱穩(wěn)定極限暫態(tài)穩(wěn)定極限靜態(tài)穩(wěn)定極限動態(tài)穩(wěn)定極限斷面潮流極限最大輸送功率極限電網可用輸電能力問題可用傳輸能力（ATC）的定義：ATC（Available Transfer Capability ）是輸電網傳輸能力的一種度量標準，它反映出在已成交的傳輸容量基礎上，輸電網對市場交易還可提供的最大傳輸容量。它隨時間的推移、電網結構的變化和斷面的不同而改變。What is Available Transfer Capability (ATC)?Some of you may be familiar with the termsTotal Transfer Capability (T

3、TC)Capacity Benefit Margin (CBM)Transmission Reliability Margin (TRM)Existing Transmission Commitments（ETC）EtcThen ATC is defined asATC = TTC CBM TRM “Existing TC”This talk will not cover these terms. We will really be covering the calculation of “TTC”, but lets not get caught up with the nomenclatu

4、re（術語）.Available Transfer CapabilityDetermines the amount of transmission capability available to transfer power from point A to point B without causing any overloads in basecase and first contingencies.Depends upon assumed system loading, transmission configuration and existing transactions.電網可用輸電能

5、力問題ATC=TTC-TRM-ETC-CBM ATC：可用傳輸容量TTC：全部傳輸容量TRM：傳輸可靠裕度ETC：現(xiàn)有傳輸計劃CBM：容量效益裕度Available Transfer CapabilityIn broad（廣泛的） terms, lets define ATC asThe maximum amount of additional MW transfer possible between two parts of a power systemAdditional means that existing transfers are considered part of the “b

6、ase case” and are not included in the ATC numberTypically these two parts are control areasCan really be any group of power injections.What does Maximum mean?No overloads should occur in the system as the transfer is increasedNo overloads should occur in the system during contingencies as the transf

7、er is increased.電網可用輸電能力問題輸電網建立開放準入機制以后，為了更好地提高轉運服務，電網必須要準確地知道自身的最大輸電能力，以及扣除實際傳輸容量以后，所能進一步完成的傳輸能力，以便準備進行更多的傳輸，預防因傳輸能力的不足而引起的阻塞現(xiàn)象發(fā)生。 電網可用輸電能力問題一系列的經濟、環(huán)境和社會約束阻礙了電網結構和輸電線路的擴展。在這種情況下，盡管電網盡可能地發(fā)展以保證輸電能力，實際上受能源分布和負荷需求雙方的制約，電網本身仍然存在阻塞和網損等問題，必須要發(fā)展一定的可以靈活調節(jié)的控制措施和設備。FACTS技術的出現(xiàn)為電網解決這一問題提供了一個有效的手段。Computational

8、Problem?Assume we want to calculate the ATC by incrementing the transfer, resolving the power flow, and iterating in this manner.Assume 10 is a reasonable guess for number of iterations that it will take to determine the ATCWe must do this process under each contingency（預想事故）.Assume we have 600 cont

9、ingencies.This means we have 10*600 power flows to solve.If it takes 30 seconds to solve each power flow (a reasonable estimate), then it will take 50 hours to complete the computation for ONE transfer direction!Contingencies 預想事故Contingencies are the unexpected loss of a significant device, such as

10、 a transmission line or a generator.No power system can survive a large number of contingencies. First contingency refers to loss of any one device.Contingencies can have major impact on Power Transfer Distribution Factors (PTDFs).Why is ATC Important?Its the point where power system reliability mee

11、ts electricity market efficiency.ATC can have a huge impact on market es and system reliability, so the results of ATC are of great interest to all involved.電網可用輸電能力問題研究方向：評估與計算市場定價ATC的提高（FACTS）電網可用輸電能力問題ATC的研究方法：連續(xù)潮流法（continuation power flow ）最優(yōu)潮流法（Optimal Power Flow）靈敏度分析法（Sensitivity Analysis）電網可

12、用輸電能力問題ATC的特點：它與傳統(tǒng)概念上的功率傳輸極限或最大傳輸容量有關，而且比它們涉及的范圍更寬 ,不僅需要計算某一輸電線路、重要斷面或母線節(jié)點的ATC，甚至還需計算同一時刻多條輸電線路、多個重要斷面或多個母線節(jié)點的ATC。此外，ATC還融入了電力市場的特征，取決于市場交易量大小、交易地點及交易合同的持續(xù)時間。因此，雖然ATC的概念本身并不復雜，但它涉及的方面卻很廣，這增加了ATC計算的難度，同時也使ATC在電力市場中的作用更大，應用范圍更廣。供電能力的含義輸電系統(tǒng)的負荷供應能力（LSC）：指一個系統(tǒng)的發(fā)電容量通過網絡后，能提供給負荷的最大功率。這一功率使發(fā)電設備沒有更多的功率可調度，也不

13、會引起網絡中任意條輸電線過負荷。電力系統(tǒng)可視化Visualization of Power SystemsNational Science Foundation, 1996Final Project Report, November 2002Power Systems Engineering Research Center (PSERC) 13 UniversitiesPowerWorld Simulator 軟件包PowerWorld SimulatorPowerWorld Simulator is an interactive, Windows based simulation program, originally designed at University of Illinois for teaching basics of power system