【作者】 艾琳；

【导师】 杨以涵； 姜彤；

【作者基本信息】 华北电力大学（北京） ， 电力系统及其自动化， 2009， 博士

【摘要】 电网互联的发展与电力市场的完善是现代电力系统发展的趋势。电力系统逐渐发展成为高维的非线性系统,运行方式越来越复杂,对电力系统的安全性提出了更高的要求。另一方面,电力市场的建立与完善对系统的经济性提出了更高的要求。在当前环境下,电力系统安全稳定与经济运行的冲突问题逐渐凸显,对互联电网在不同运行情况下的经济性和安全性做出合理评估,能够为运行人员采取合理的调度和控制措施提供决策支持,有利于保证电力系统的安全稳定与经济优质运行。针对新环境下互联电网日益凸显的电压安全问题、电网快速发展过程中的电磁环网问题、跨区域水火电经济调度问题,本文从电压稳定在线评估指标,无功电源的重要性评估,电磁环网运行的风险评估,以及水火电系统调度的经济性评估等几个方面入手,分别对电网的安全性与经济性评估的若干问题进行了研究,主要工作如下:电压稳定的在线安全评估是关系到电力系统安全稳定运行的重要问题。本文首先对电压稳定的在线判别方法进行了研究,提出了一种基于Ybus形式的在线电压稳定分析方法,该方法推导了由电压变化量发生幅值递增的自激放大所引起的电压单调失稳模式,并且在计算中考虑了系统的动态变化,具有原理简单计算量小的优点;其次,对电压稳定使用最广泛的负荷裕度指标进行了研究,提出一种基于WAMS的同步测量技术的负荷裕度在线计算新方法,由此得出的电压稳定有功和无功裕度指标,能够明确区分系统由于有功过重还是无功缺乏引起的电压失稳;考虑到无功电源出力是影响系统电压稳定性的重要因素之一,本文将风险评估方法与等效无功补偿方法相结合,提出一种基于风险理论的无功电源重要性评估新方法,能够为系统运行人员进行无功调整或电源规划提供相应的决策支持。对于电网快速发展过程中出现的电磁环网问题,本文将风险理论应用于电磁环网的安全分析,提出一种基于效益风险函数的电磁环网风险评估与控制方法。该方法分别计算了电磁环网的静态风险、暂态风险以及系统总的风险,以及采取安全稳定控制措施对系统风险的影响,并引入效益风险函数对不同运行状态下的系统收益与风险的取舍进行分析,能够为电磁环网的控制方案制定提供决策支持,以实现降低电磁环网运行风险的目的。针对互联电网的水火电系统经济调度问题,本文提出一种基于模糊优化和内点法的水火电系统短期经济调度方法。该方法考虑了来水量的不确定因素,采用模糊优化方法对水火电系统进行平衡,采用原对偶内点算法求解该多目标混合非线性规划问题,取得了较好的收敛性能,并在一定程度上提高了系统的经济性。更多还原

【Abstract】 The interconnection of larger scale power networks and the consummation of power market have become an inevitable trend of modern power system.With the building of Ultra High Voltage(UHV) power system in china,the system is changing into one of the extra large synchronous AC transmission systems in the world.The interconnection of power grids has changed the power system into a high dimensions,strongly nonlinear system,and the complex operating mode brings forward more request to the security of the power grid.On the other hand,the contribution and consummation of power market has proposed more request to the economy of the power grid.As the problems of voltage stability,electromagnetically coupled power loop during the processing of grid fast development,economic of hydro-thermal economic dispatch are more serious of the interconnected power grid.In this paper,correlated problems of the power system security and economy assessment are analyzed,main research work and contributions are summarized as follows:Voltage stability assessment is one of the most important security to power system’s secure and stable running.Firstly,the paper proposes a new method of on-line voltage stability analysis based on Ybus form and deduces monotone mode of voltage instability resulted by divergence of voltage iteration.Secondly,a new criteria of on-line voltage stability index based on load margin is proposed by use of the local measurements data of synchronous phase measure uints(PMU),thus indices of active power margin and reactive power margin can be calculated respectively,which can distinguish voltage unstability caused by overload from the lack of reactive power.The third,as the assessment of reactive power sources is a great need for system operators in an open access environment,this paper presents a novel approach to assessment importance of reactive power sources in power market based on risk theory,it accounts for both the uncertainties on the system and the consequences associated with the output of the reactive power sources.The operation of electromagnetically coupled power loop brings more risk to system running.In this paper,a new risk assessment and control method for electromagnetically coupled power loop is provided.Firstly,the security of the grid is assessed.The static risk,the transient risk and the overall risk are obtained.And the change of the risk with and without the using of security and stability equipment are obtained also.Secondly,the economical of electromagnetically coupled power loop and security and stability equipment as well as the value of risk benefit function are calculated.Based on these,the various of economical of risk are analyzed during different system states.The analyzed results provide effective supports for system operators.In order to solve the conservation on economic of a short term hydro-thermal coordinated economic dispatch model,a new short term hydro-thermal coordinated economic dispatch method is proposed.The uncertainty of water value is considered in this method,the fuzzy optimization is used to balance the two objectives,thus the hydro-system and the thermal-system are traded off,and the primal-dual interior point method(PDIPM) is used to solve this multi-objective fuzzy optimization problem for its good convergence probability.Compared with traditional methods,the proposed method improves the system economic to some extent.更多还原