Numerical Method to Analyze the Nonlinear Dynamical Structure of Multi-machine Power System

电力系统是一个非线性动态大系统。电力系统的暂态稳定分析是非线性系统分析领域的一个例子，其中重点放在二阶动态的分界线上。本文的研究目的是建立一种基于Hopf分岔理论的多机电力系统非线性动力学的数值分析方法。电力市场的开放是电力系统发展的一个新趋势，电力市场的开放将促使各种发电商参与电力市场。在这种情况下，电力传输所有者寻求经济运行，这可能接近稳定极限。因此，非线性系统分析成为系统运行中的一个重要问题。本文提出了一种分析具有纵向互联的多机电力系统非线性结构的方法。高阶系统的非线性分析随着系统阶数的增加而变得越来越困难。因此，一个数值方法的基础上获得的摆动数据从电力系统，开发。用该方法分析了西日本电力系统中观测到的一个长期功率振荡，并检测到由非线性周期轨道产生的稳定边界。并对发电机励磁系统的效果进行了检验。

Power system is a large scale nonlinear dynamic system. The transient stability analysis of power system is an example associated with the area of the nonlinear system analysis, where the emphasis has been placed on the separatrix of second-order dynamics. The purpose of this research is to develop a numerical analyzing method for the nonlinear dynamics of multi-machine power system using Hopf bifurcation theory.It is a recent trend of power systems to open the market, where various kinds of power producers are expected to join the power business. In the circumstances, power transmission owners look for an economical operation, which is possibly near the stability limit. Thus, the nonlinear system analysis becomes an important issue in the system operation.In this study a method to analyze the nonlinear structure of multi-machine power system with longitudinal interconnections. Nonlinear analysis for a high order system is getting much difficult as the order increases. Therefore, a numerical method based on the swing data obtained from the power system, is developed. A long term power swing observed in the West Japan power system is analyzed by the proposed method and a stability boundary created by the nonlinear periodic orbit is detected. The effect of the generator excitation system is also inspected.