电力系统复习课件2005级暂态

1、电力系统分析Power System Analysis 艾 欣 教授、博士生导师 电力工程系副主任 电子邮件： 办公室：教五楼C416房间 电话： 80795848 POPO账号：simonxinai内容提要电网可用输电能力（ATC）电力系统可视化供电能力的含义充足的供电能力应该包括：充足的电源（装机容量充足、电源种类构成合理、电源调节能力强）；合理的电网结构和传输能力；适当的电网规模。供电能力的含义电源的供应能力和电网的供应能力满足电力的能力满足电量的能力满足供电可靠性的能力满足电能质量的能力满足长期、短期电力需求的能力满足电力市场条件下负荷需求的能力有黑启动，在大停电后具有快速恢复供电的能

2、力。线路的输送功率极限热稳定极限暂态稳定极限静态稳定极限动态稳定极限断面潮流极限最大输送功率极限电网可用输电能力问题可用传输能力（ATC）的定义：ATC（Available Transfer Capability ）是输电网传输能力的一种度量标准，它反映出在已成交的传输容量基础上，输电网对市场交易还可提供的最大传输容量。它随时间的推移、电网结构的变化和断面的不同而改变。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（术语）.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.电网可用输电能

5、力问题ATC=TTC-TRM-ETC-CBM ATC：可用传输容量TTC：全部传输容量TRM：传输可靠裕度ETC：现有传输计划CBM：容量效益裕度Available Transfer CapabilityIn broad（广泛的） 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.电网可用输电能力问题输电网建立开放准入机制以后，为了更好地提高转运服务，电网必须要准确地知道自身的最大输电能力，以及扣除实际传输容量以后，所能进一步完成的传输能力，以便准备进行更多的传输，预防因传输能力的不足而引起的阻塞现象发生。 电网可用输电能力问题一系列的经济、环境和社会约束阻碍了电网结构和输电线路的扩展。在这种情况下，尽管电网尽可能地发展以保证输电能力，实际上受能源分布和负荷需求双方的制约，电网本身仍然存在阻塞和网损等问题，必须要发展一定的可以灵活调节的控制措施和设备。FACTS技术的出现为电网解决这一问题提供了一个有效的手段。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（预想事故）.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 预想事故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.电网可用输电能力问题研究方向：评估与计算市场定价ATC的提高（FACTS）电网可用输电能力问题ATC的研究方法：连续潮流法（continuation power flow ）最优潮流法（Optimal Power Flow）灵敏度分析法（Sensitivity Analysis）电网可

12、用输电能力问题ATC的特点：它与传统概念上的功率传输极限或最大传输容量有关，而且比它们涉及的范围更宽 ,不仅需要计算某一输电线路、重要断面或母线节点的ATC，甚至还需计算同一时刻多条输电线路、多个重要断面或多个母线节点的ATC。此外，ATC还融入了电力市场的特征，取决于市场交易量大小、交易地点及交易合同的持续时间。因此，虽然ATC的概念本身并不复杂，但它涉及的方面却很广，这增加了ATC计算的难度，同时也使ATC在电力市场中的作用更大，应用范围更广。供电能力的含义输电系统的负荷供应能力（LSC）：指一个系统的发电容量通过网络后，能提供给负荷的最大功率。这一功率使发电设备没有更多的功率可调度，也不

13、会引起网络中任意条输电线过负荷。电力系统可视化Visualization of Power SystemsNational Science Foundation, 1996Final Project Report, November 2002Power Systems Engineering Research Center (PSERC) 13 UniversitiesPowerWorld Simulator 软件包PowerWorld SimulatorPowerWorld Simulator is an interactive, Windows based simulation program, originally designed at University of Illinois for teaching basics of power system