基于正则形理论的非线性稳定因子

Nonlinear Stability Indexes Based on Normal-Form Theory

在正则形二阶变换基础上,通过研究变换过程中省略的交叉项和省略的三阶项,提出了分析大扰动下电力系统稳定的非线性稳定因子的新概念,即阻尼因子和稳定域因子的新概念。通过阻尼因子可分析大扰动下正则形变量幅值发生变化的快慢,在此基础上再通过稳定域因子的计算得到大扰动下正则形变量稳定的区域,进而判断系统稳定情况。这些稳定信息是无法从以往的分析理论和方法中得到的,这从另一侧面为系统的稳定分析提供了一条可行途径。电力系统算例仿真结果证明了本文所提出非线性稳定因子这一新概念的正确性和在电力系统中应用的有效性。

A new concept called as non-linear stability factor which can be used to analyze power system stability under large disturbance is first proposed in this paper by researching the transform process of abridged cross-term and third order-term in normal form second-order transformation.That is damping factor and stability domain factor.The variation speeds of normal form variable amplitude under large disturbance can be analyzed by damping factor.On this basis,normal form variable stability domain under large disturbance can be acquired by calculating the stability domain factor,and then judging the system stability.These information of stability cannot be obtained from the existing analysis theory and method,so it provides a feasible approach to analysis the system stability by using another point of view.Simulation results of an example prove the correctness and effectiveness of the proposed concept.