【作者】 李传栋；

【导师】 房大中；

【作者基本信息】 天津大学 ， 电力系统及其自动化， 2005， 硕士

【摘要】 电力系统数字仿真是研究电力系统的重要工具,具有不可替代的作用。随着电力系统规模不断扩大,容量不断增大,电压等级不断提高,新的元器件不断应用到系统当中。工程应用中对电力系统数字仿真的要求逐步提高,一方面要求数字仿真具有良好的精确度,另一方面对仿真程序的速度有更高的要求,此外要求仿真程序有一定可扩展性,能够方便地添加的新的器件模型。本文的主要工作旨在改进仿真算法,满足上述要求。本文首先分析电力系统各个组成部分的数学模型,阐述了电力系统数字仿真的整体思路。给出了用于电力系统暂态仿真的网络、发电机、励磁器等控制器的数学模型。从数学概念出发,阐述了Newton法的基本思想。分析了影响暂态仿真计算速度的主要因素,指出迭代过程中重复进行的Jacobian矩阵的修正和分解是提高暂态稳定仿真速度的瓶颈。本文介绍了双向模块简化方法原理,通过和传统方法比较说明了双向模块简化方法具有无交接误差,收敛性好,且可模块化编程的优点。利用其正向简化和反向回代方法对电力系统网络和发电机等子模块进行了公式推导,得到编程可用的方程。利用第三章的推导结果,比较网络和发电机模块方程的Jacobian矩阵。根据矩阵的特点,本文采用部分矩阵分解的方法来提高暂态仿真的效率。Jacobian矩阵在仿真过程中除发生网络结构改变以外,只对与修正元相关的部分进行分解,并结合保存的矩阵分解结果得到和完整的矩阵LU分解相同的结果。算法优化之后,矩阵分解的工作量得到降低,仿真速度有较大提高,同时算法保持牛顿法良好的收敛性。最后编写了电力系统暂态仿真应用程序。分别以我国蒙西,山西,东北三个不同规模的实际电力网络为算例进行仿真验证。并且以BPA的仿真结果为标准,进行精度和计算速度的比较,比较结果说明了本文提出的优化方法的正确性和有效性。更多还原

【Abstract】 The time-domain trajectory simulation is one of the necessary tools to study thepower system behavior. The simulation provides data for many system securityanalyses. With the enlargement in system scale and capacity and the application ofnew facilities, the power system becomes much more complex to analyze. Thus theprogramming of the digital simulation in power system engineering has become morechallenging too: not only in accuracy but also in speed. In addition it should beconvenient to add models of new equipments to simulation programs. The main workof the thesis aims at improving the transient simulation algorithm to meet theserequirements.First, the general procedure of the system simulation is presented, followed by themathematic models of various components and their differential equations accordingto the trapezoidal rule. The basic idea of the Newton method is discussed, in whichthe repetitive reform and LU decomposition of Jacobian matrix impose a heavycomputational burden. This is the bottleneck to enhance the speed of transientsimulation.In Chapter 3, a technique of Bidirectional Module Reduction (BMR) isintroduced. By means of the BMR technique, the simulation programming based onNewton iteration has been modularized and easier to be expanded, with quickconvergence, high precision and good numerical stability. Equations of power gridand generators with their auxiliary controllers are derived for code program namedforward reduction and backward substitution method.To improve the efficiency of system simulation, certain inherent attributes inJacobian matrices of electric network and generator modules are utilized. This buildsthe basis of partial matrix decomposition technique in Chapter 4. During iterations,the decomposition of the Jacobian matrix will be restricted within a small sub-matrix,but retain the same result of decomposition for full Jacobian matrix. Thecomputational burden of LU decomposition is thus greatly reduced, while the fastconvergence of Newton iteration will remain.Finally, a simulation program using the new techniques is developed. Casestudies using the program are carried out on three realistic electric networks inChina—i.e. Mengxi, Shanxi and Northeast systems. Swing curves and simulation timeare compared with those obtained by BPA. They validate that the simulation speed oflarge scale system has been greatly enhanced更多还原