潮流计算文献翻译开题报告.docx

1、潮流计算文献翻译开题报告南 昌 工 程 学 院 07 级毕业（设计）论文文献翻译机械与电气工程 系（院） 07电气工程及自动化 专业 题 目 基于Matlab的电力系统潮流仿真计算（直角坐标） 姓 名 孙 进 班 级 07电气工程及自动化（1）班 学 号 * 指 导 教 师 章 顺 华 日 期 2011 年 1 月 3 日南 昌 工 程 学 院 教 务 处 订 制评语： 指导教师： 年 月 日基于Matlab的电力系统潮流仿真计算（直角坐标）摘要： 潮流计算是电力系统的一项重要分析功能，是进行故障计算，继电保护整定，安全分析的必要工具。结合电力系统的特点，利用 MATLAB语言运行电力系统潮流

2、计算，再结合牛顿拉夫逊法潮流计算（直角坐标），主要特点是操作简单，软件运行稳定.计算准确，提高了计算速度。关键词：电力系统潮流计算 MATLAB 牛顿拉夫逊法潮流计算引 言 为了提高供电可靠性以及资源利用的综合经济性，把许多分散的各种形式的发电站，通过送电线路和变电所联系起来。这种由发电机、升压和降压变电所，送电线路以及用电设备有机连接起来的整体，即称为电力系统。电力系统运行方式管理中，潮流计算是确定电网运行方式的基本出发点；在规划领域，需要进行潮流计算分析验证规划方案的合理性；在实时运行环境，调度员潮流提供了电网在预想操作情况下电网的潮流分布以校验运行可靠性。在电力系统调度运行的多个领域都涉

3、及到电网潮流计算。潮流计算是确定电力网络运行状态的基本因素，潮流计算问题是研究电力系统稳态问题的基础和前提。利用 MATLAB语言运行电力系统潮流计算，再结合牛顿拉夫逊法潮流计算（直角坐标），是一种常规的算法。1.潮流计算简介电力系统潮流计算也分为离线计算和在线计算两种，前者主要用于系统规划设计和安排系统的运行方式，后者则用于正在运行系统的经常监视及实时控制。利用电子数字计算机进行电力系统潮流计算从50年代中期就已经开始。潮流计算曾采用了各种不同的方法，这些方法的发展主要围绕着对潮流计算的一些基本要求进行的。而牛顿拉夫逊法潮流计算是最普遍的一种潮流计算法。2.潮流计算的要求电力系统潮流计算问题

4、在数学上是一组多元非线性方程式求解问题，其解法都离不开迭代。对潮流计算的要求可以归纳为下面几点：（1）计算方法的可靠性或收敛性；（2）对计算机内存量的要求；（3）计算速度；（4）计算的方便性和灵活性。由于电力系统结构及参数的一些特点，并且随着电力系统不断扩大，潮流计算的方程式阶数也越来越高，对这样的方程式并不是任何数学方法都能保证给出正确答案的。这种情况成为促使电力系统计算人员不断寻求新的更可靠方法的重要因素。3.牛顿拉夫逊法潮流计算（直角坐标）简介及特点1.牛顿拉夫逊法是常用的解非线性方程组的方法，它是指每一次迭代过程中，对非线性方程组通过线性化处理逐步近似，从而求解非线性方程组。也是目前广

5、泛采用的计算潮流的方法。利用迭代算法解决问题，需要做好以下两个方面的工作： 一、确定迭代变量。在可以用迭代算法解决的问题中，至少存在一个直接或间接地不断由旧值递推出新值的变量，这个变量就是迭代变量。 二、建立迭代关系式。所谓迭代关系式，指如何从变量的前一个值推出其下一个值的公式（或关系）。迭代关系式的建立是解决迭代问题的关键，通常可以使用递推或倒推的方法来完成。2牛顿拉夫逊法潮流计算是以导纳矩阵为基础的，由于利用了导纳矩阵的对称性，稀疏性及节点编号顺序优化等技巧，使牛顿拉夫逊法潮流计算在收敛性，占用内存，计算速度方面的优点都比以往的算法更好，同时广泛应用于非线性规划法，直流法，交流法等不同的潮

6、流计算。进而派生出更快的PQ分解法。3但是牛顿拉夫逊法对初值的选择要比较接近他们的精确解，否则迭代过程将不收敛，因此，某些采用牛顿拉夫逊法计算的潮流程序中，第一，二次采用高斯赛德尔法迭代几次4.对网络节点的规定1.PQ节点对这一类点，事先给定的是节点功率(P，Q)，待求的未知量是节点电压向量(U，)，所以叫PQ节点。2. PU节点这类节点给出的参数是该节点的有功功率P及电压幅值U，待求量为该节点的无功功率Q及电压向量的相角。3. 平衡节点在潮流计算中，这类节点一般只设一个。对该节点，给定其电压值，并在计算中取该节点电压向量的方向作为参考轴，相当于给定该点电压向量的角度为零。5节点电压方程和导纳

7、矩阵电力网络的节点电压方程： (5-1)为节点注入电流列向量，注入电流有正有负，注入网络的电流为正，流出网络的电流为负。根据这一规定，电源节点的注入电流为正，负荷节点为负。既无电源又无负荷的联络节点为零，带有地方负荷的电源节点为二者代数之和。为节点电压列向量，由于节点电压是对称于参考节点而言的，因而需先选定参考节点。在电力系统中一般以地为参考节点。如整个网络无接地支路，则需要选定某一节点为参考。设网络中节点数为（不含参考节点），则，均为n*n列向量。为n*n阶节点导纳矩阵。节电导纳矩阵的节点电压方程： (5-2) 结束语经过上面五个步骤，我们就可以利用Matlab软件对给定的网络进行初步的潮流

8、计算。在电力系统调度运行的多个领域都涉及到电网潮流计算。潮流是确定电力网络运行状态的基本因素，在这个意义上，我们在编制潮流计算程序时，对使用的方便性和灵活性必须予以足够的重视。因此，除了要求计算方法尽可能适应各种修改.调整以外，还要注意输入和输出的方便性和灵活性，加强人机联系，以便使计算人员能及时监视计算过程并适当地控制计算的进行。参考文献：1.何仰赞.温增银电力系统分析.华中科技大学出版社2.吴天明Matlab电力系统设计与分析国防工业出版社3.韩帧祥.吴国炎 电力系统分析 浙江大学出版社4.Nagrath I J，Kothari D R. Modern Power System Analy

9、sis.New Delhi：TataMcGraw-Hill Publishing Company.5.Elgred O I.Electric Energy System Theory-An Introduction.McGraw-Hill Book Co. The power system based on Matlab simulation calculation (rectangular trend)Abstract： Flow calculation is an important power system fault analysis function, is calculated,

10、relay protection setting, safety analysis tools necessary to combine power system characteristics, the use of MATLAB language power system operation flow calculation, coupled with Newton rafer Johnson method flow calculation (rectangular), main characteristic is a simple operation, the software runn

11、ing stability.Keyword： Power system flow calculation MATLAB Newton rafer Johnson flow calculation method Introduction In order to improve the power supply reliability and resource utilization of comprehensive economic, many scattered the various forms of power stations, through the transmission line

12、s and link this by generator substation pressor and step-down substation, power transmission lines and equipment organic connecting the whole, namely called power systemPower system operation mode of management, flow calculation is to determine the grid operation mode of the basic point of departure

13、, In the planning area, need to undertake flow calculation analysis verify the rationality of the planning scheme, In real-time operating environment, the dispatcher tide provides power grid operation circumstance in expected by the trend of calibration operation reliability distribution in power sy

14、stem, adjustable.1.Flow calculation profilePower system flow calculation are offline calculation and online calculation two kinds, the former mainly used for system design and planning and arrangement of system operation mode, the latter for running system often surveillance and real-time control Us

15、ing digital electronic computer power system flow calculation from mid 1950s began flow calculation has adopted various method, these methods development mainly revolves around to flow calculation of some basic requirements while Newton rafer Johnson flow calculation method is the most popular a kin

16、d of tide calculation method2. Flow calculation requirementsPower system flow calculation problem in mathematics is a group of multivariate nonlinear equations solving problem, its solution is inseparable from the iteration to flow calculation requirements can be summarized as below when(1) the calc

17、ulation method of reliability and convergence (2) for inside a computer stock requirements(3) computational speed(4) calculating convenience and flexibilityBecause the power system structure and parameters, and with some characteristics of the power system expands unceasingly, flow calculation equat

18、ions order number also more and more high, to such equations is not any mathematical method can guarantee gives the correct answer this kind of condition be prompted electricity system calculation personnel seeking for new more reliable method of important factor3. Newton rafer Johnson method flow c

19、alculation (rectangular trend) introduction and characteristics1. Newton rafer Johnson method is a common method of solving nonlinear equations, it is to point to each iteration process, the nonlinear equations by linearization gradually approximation, thus solving nonlinear equations is now widely

20、used method of calculating tideUsing iterative algorithm for solving problems, needs to be the following two aspects：One Sure iteration variable in can use iterative algorithm to solve the problems, at least, there exists a directly or indirectly by old constantly introducing new values of the recur

21、sive value, the variable is variable iteration variableTwo Iterative equation of so-called iterative equation established, refers to how from before the launch of a value of the variable underneath a value of the formula (or relationship) is built to solve the iterative equation of iterative the cru

22、x of the problem, often can use recursion or reverse push way to accomplish2. Newton rafer Johnson flow calculation method based on admittance matrix, because of using admittance of symmetry sparseness matrix, and the node number sequence optimization techniques enables Newton rafer Johnson flow cal

23、culation method in convergence, memory and computing speed is the advantage of the algorithm is better than ever before, and widely used in nonlinear programming method， Dc law, communication method of different flow calculation and derive faster PQ decomposition method3. But Newton rafer Johnson me

24、thod of initial choice wants to be close to their exact solutions, otherwise iterative process will not converge, therefore, some by Newton rafer Johnson method to calculate the trend of program, first, second by Gauss del method iterative several times 4. The provisions of network nodes1. The PQ no

25、de：Prior to this kind of point, given is a node power (P, Q), to seek the unknown variables are node voltage vector (U), so they are called the PQ node2. PU nodeThis kind of node parameter is given of the node active power P and voltage amplitude U, stay for quantity is of the node reactive power an

26、d voltage vector of the phase Angle Q3. Balance nodeIn tide calculation, this kind of node set a to only commonly the node, given its voltage value, and take in calculation the node voltage vector direction as reference axis, equivalent to a given point voltage vector Angle for zero5. Node voltages

27、equation and admittance matrix Power network node voltage equation ： (5-1)，For nodal injection current columns, inject current with a negative, there is the current network is injected, the outflow of current network for negative according to this regulation, power source node is injected into the c

28、urrent load node is negative, neither power nor load contact node is zero, with local load power node is the sum of them algebra，For node voltages columns, due to the node voltages are symmetry for reference node concerned, so must first selected reference node in the power system for reference in g

29、eneral like the whole network node without grounded branch, and is in need of selected a node for reference number of nodes in a network (not including reference node), then, are all n * n columns for n * n order section.Electricity-saving admittance matrix of the node voltages equation： (5-2)Closin

30、gThrough the above five steps, we can use of Matlab software to a given network carries on the preliminary flow calculation.In power system scheduling the execution of multiple fields involve power flow calculation trend is to determine the electric power network operation state of basic factors, an

31、d in this sense, we are compiling flow calculation program, to use the convenience and flexibility must give enough attention .Accordingly, besides requirements calculation method as adapt to modify. Adjust the outside, but also pay attention to the input and output of convenience and flexibility, a

32、nd strengthen the man-machine contact calculation personnel, in order to make timely monitoring calculation process and appropriately control calculationReferences: 1.何仰赞.温增银 电力系统分析.华中科技大学出版社2.吴天明Matlab电力系统设计与分析国防工业出版社3.韩帧祥.吴国炎 电力系统分析 浙江大学出版社4.Nagrath I J，Kothari D R. Modern Power System Analysis.New Delhi：TataMcGraw-Hill Publishing Company.5.Elgred O I.E