基于广域测量技术戴维南等值参数的计算及在电压稳定性分析中的应用

发布时间：2018-01-24 13:56

本文关键词： 电力系统戴维南等值参数导纳矩阵电压稳定　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：现代电力系统作为当今规模最大、结构最复杂的人造系统之一，其稳定性问题一直是电力科研人员比较关注和重视的课题。通过研究发现整个系统的稳定性往往与某一点或某一区域的稳定有着密切的联系，于是怎样找到电压薄弱节点成为对该节点进行电压稳定性分析的关键。由于电压崩溃具有隐蔽性和突发性，因此对电压薄弱节点的监控是非常必要的。寻找电压薄弱节点的方法往往是采用跟踪节点的戴维南等值参数，所以，戴维南等值参数值要务必精确，只有快速的寻找到系统的电压薄弱节点和薄弱区域并对该节点或区域进行调控才能确保整个系统的稳定运行。本文从这一角度出发，将广域测量技术相量测量单元的测量结果用于论文提出的计算方法，对研究节点的戴维南等值参数进行求解。用全导纳矩阵求解戴维南等值参数的方法理论严谨，不存在任何假设条件，同时对某时刻的戴维南等值参数的求解只需该时刻的参数向量，避免了采用不同时刻参数值带来的零点漂移问题。论文通过理论分析及算例证明得出了节点自阻抗与该节点戴维南等值阻抗以及负荷阻抗之间存在的重要关系：自阻抗等于该节点戴维南等值阻抗与负荷阻抗的并联。由于采用的戴维南等值阻抗求解方法依赖于对节点网络方程导纳矩阵逆矩阵的求解，从求解公式可以看出矩阵A、B、C、D均为对称矩阵，所以，本文对电力系统中对称矩阵逆矩阵的求解过程给出了新的计算方法：首先将对称矩阵分解为LDLT的形式，再分别对三角矩阵进行求逆。为保证戴维南等值参数计算方法的正确性，采用简单三节点网络就论文提出的方法给与了证明，通过公式对比，可以看出本文提出的求解戴维南等值参数的方法不存在理论误差。该方法可应用于电力系统中的任意负荷节点，，且适用于戴维南等值参数的静态和动态求解，以便确保对系统状态进行实时跟踪。采用IEEE14节点系统对本文提出的计算方法进行仿真计算，通过对不同方法节点的戴维南等值参数的计算和比较，可以看出本文采用的方法计算精度高，过程简单，具有更好的实际应用价值。另外论文在戴维南参数等值的基础上对系统负荷节点的阻抗模裕度进行了求解，并对某一特定节点进行了电压稳定性分析。
[Abstract]:Modern power system is one of the largest and most complex artificial systems. The stability of the whole system is often closely related to the stability of a certain point or region. So how to find the weak voltage node becomes the key to the voltage stability analysis. Because the voltage collapse is hidden and sudden, it is very necessary to monitor the weak voltage node. The method to find the weak voltage node is to use the Thevenin equivalent parameter of the tracking node. Thevenin's equivalent values must be accurate. Only by finding the weak voltage node and the weak area of the system quickly and regulating the node or region can we ensure the stable operation of the whole system. The measurement results of wide-area measurement technology phasor measurement unit are applied to the calculation method proposed in this paper. The method of using the full admittance matrix to solve the Thevenin equivalent parameters is rigorous in theory, and there are no hypothetical conditions. At the same time, the solution of the Davinan equivalent parameters at a certain time requires only the parameter vector of that moment. The 00:00 drift problem caused by using parameters at different times is avoided. The important relationship between node self-impedance, Thevenin equivalent impedance and load impedance is obtained by theoretical analysis and numerical example. The self-impedance is equal to the equivalent impedance of the node in parallel with the load impedance. The solution method of the Thevenin equivalent impedance depends on the solution of the inverse matrix of admittance matrix for the node network equation. From the solution formula, we can see that the matrix A BX C D is all symmetric matrix, so. In this paper, a new method for solving the inverse matrix of symmetric matrix in power system is presented. Firstly, the symmetric matrix is decomposed into the form of LDLT. In order to ensure the correctness of the Thevenin equivalent parameter calculation method, the method proposed in this paper is proved by simple three-node network, and the formula is compared. It can be seen that there is no theoretical error in the method proposed in this paper for solving the Thevenin equivalent parameters. This method can be applied to arbitrary load nodes in power system and can be used to solve the static and dynamic parameters of Davinan equivalent parameters. In order to ensure the real-time tracking of system state, the proposed method is simulated by using IEEE14 node system, and the calculation and comparison of the Thevenin equivalent parameters of different method nodes are carried out. It can be seen that the method used in this paper is of high accuracy, simple process and better practical application value. In addition, the impedance modulus margin of the load node of the system is solved on the basis of the equivalent of Davinan parameters. The voltage stability of a particular node is analyzed.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM712

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