電力系統(tǒng)復(fù)習(xí)課件2005級(jí)暫態(tài)

1、電力系統(tǒng)分析Power System Analysis 艾 欣 教授、博士生導(dǎo)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(hào)：simonxinai內(nèi)容提要電網(wǎng)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(yīng)該包括：充足的電源（裝機(jī)容量充足、電源種類構(gòu)成合理、電源調(diào)節(jié)能力強(qiáng)）；合理的電網(wǎng)結(jié)構(gòu)和傳輸能力；適當(dāng)?shù)碾娋W(wǎng)規(guī)模。供電能力的含義電源的供應(yīng)能力和電網(wǎng)的供應(yīng)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(zhì)量的能力滿足長(zhǎng)期、短期電力需求的能力滿足電力市場(chǎng)條件下負(fù)荷需求的能力有黑啟動(dòng)，在大停電后具有快速恢復(fù)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(dòng)態(tài)穩(wěn)定極限斷面潮流極限最大輸送功率極限電網(wǎng)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(wǎng)傳輸能力的一種度量標(biāo)準(zhǔn)，它反映出在已成交的傳輸容量基礎(chǔ)上，輸電網(wǎng)對(duì)市場(chǎng)交易還可提供的最大傳輸容量。它隨時(shí)間的推移、電網(wǎng)結(jié)構(gòu)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(shù)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(wǎng)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(jì)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(wǎng)可用輸電能力問題輸電網(wǎng)建立開放準(zhǔn)入機(jī)制以后，為了更好地提高轉(zhuǎn)運(yùn)服務(wù)，電網(wǎng)必須要準(zhǔn)確地知道自身的最大輸電能力，以及扣除實(shí)際傳輸容量以后，所能進(jìn)一步完成的傳輸能力，以便準(zhǔn)備進(jìn)行更多的傳輸，預(yù)防因傳輸能力的不足而引起的阻塞現(xiàn)象發(fā)生。 電網(wǎng)可用輸電能力問題一系列的經(jīng)濟(jì)、環(huán)境和社會(huì)約束阻礙了電網(wǎng)結(jié)構(gòu)和輸電線路的擴(kuò)展。在這種情況下，盡管電網(wǎng)盡可能地發(fā)展以保證輸電能力，實(shí)際上受能源分布和負(fù)荷需求雙方的制約，電網(wǎng)本身仍然存在阻塞和網(wǎng)損等問題，必須要發(fā)展一定的可以靈活調(diào)節(jié)的控制措施和設(shè)備。FACTS技術(shù)的出現(xiàn)為電網(wǎng)解決這一問題提供了一個(gè)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(yù)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(yù)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(wǎng)可用輸電能力問題研究方向：評(píng)估與計(jì)算市場(chǎng)定價(jià)ATC的提高（FACTS）電網(wǎng)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(wǎng)可

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

13、會(huì)引起網(wǎng)絡(luò)中任意條輸電線過負(fù)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