【作者】 郭建峰；

【导师】 王克文；

【作者基本信息】 郑州大学 ， 电力系统及其自动化， 2005， 硕士

【摘要】 确保电力系统的安全经济运行,维持良好的供电质量,是现代社会的基本需要,也是电力系统规划设计人员和运行管理人员一直努力追求的目标。最优潮流作为满足这一目标的重要手段之一,自其诞生之日起便成为许多电力系统科研人员十分关心的热门课题。它是典型的大型多约束非线性规划问题。随着电力市场的逐步发展及电力企业商业化运营,电力系统需要越来越灵活的潮流控制手段。FACTS技术应用电力电子技术和现代控制技术来实现对交流输电系统的快速灵活控制,使输电系统的功率输送能力、潮流和电压的可控性以及系统运行的稳定性、安全性得到较大的提高。同时,FACTS元件的加入,也对电力系统提出了新的要求和挑战。为了进行计及多运行方式和FACTS装置的概率优化分析,本文完成以下功能模块的工作。 先不考虑FACTS装置,实现概率无功优化计算。采用均值、方差交替进行的方式,优化过程中的状态变量是所有节点电压的均值,方差则随均值的变化而变化。优化方面,采用收敛性比较好的牛顿法,该方法具有收敛性好、计算速度快和精度高的特点;概率方面,考虑到二阶协方差阵,计及了各节点注入功率的一阶相关性。目标函数采用网损最小。并对IEEE14节点系统进行无功优化,取得预期结果。 为了在概率潮流计算中计及FACTS装置,在分析UPFC结构、工作原理以及作用方式的基础上,确定了含UPFC的潮流计算模型。运用等效功率注入法,将UPFC的作用转移至UPFC所在支路的两端节点。本文采用直角坐标,以电压的实、虚部作为状态变量,节点无功为控制变量,计及UPFC控制的线路潮流约束。在雅可比矩阵中加入与UPFC相关的元素,运用牛顿—拉夫逊法进行求解。 在以上工作基础上,进行含有UPFC的最优潮流计算。以网损最小为目标函数,以电压的实、虚部作为状态变量,节点无功为控制变量,计及UPFC控制的线路潮流约束,并对Ward & Hale 6节点系统进行了试算。更多还原

【Abstract】 It’s a basic need for modern society to insure safe and economical system operation and maintain good power quality. It’s also the aim of the planning, operating and administrating people in power systems. As one of the important means for meeting this aim, Optimal Power Flow became the pop problem for many power science researchers since it came into being. It’s a typical large-scale non-linear programming problem. With the gradual development of the electric market and the electric enterprise’s commercialized operation, to control power flow, more and more flexible means for power control are required. FACTS (Flexible AC Transmission System) applies the electric electronic technique and modern control technique forms quick flexible control for AC transmission system, so as to improve the transmit capacity of transmission system, the controllability of power flow and voltage, as well as the system stability and security. Meanwhile, new demand and challenge come with the use of FACTS devices. In order to analyze probabilistic load flow with multi-operating conditions and FACTS devices, the following function works are carried out.Without FACTS devices, the probabilistic reactive optimization is carried out. The alternative calculation of expectations and covariance was used. The state variables in optimization problem are all of the expectations of bus voltages, covariances are varied with expectations. In the optimal aspect, the Newton’s method was used which possesses a good convergency, fast solution speed and high precision. In the probabilistic aspect, the second order moment, i.e. covariance was used, which took the first order correlation between nodal powers into account. The objective function is the minimum power loss. The IEEE-14 buses system has been tested.In order to take FACTS devices in the probabilistic load flow, from the analysis of UPFC’s structure, operation principle and action mode, the power flow calculation model including UPFC is determined. By means of the equivalent power flow injection approach, the function of UPFC is transferred to the two ending nodes of the branch that UPFC exists. In this thesis, the rectangular form is used. State variables are nodal voltages, control variables are nodal reactive power. The UPFC branch power constraint is considered. With elements related to UPFC are added into the Jacobianmatrix, Newton method is used to solve the problem.From above works, the optimal power flow problem including UPFC is carried out. The objective function is the minimum power loss. State variables are nodal voltages, control variables are nodal reactive power. The UPFC branch power constraint is considered. The calculation for Ward & Hale 6-bus system is carried out.更多还原