应用潮流方程简化网络计算的电力系统小干扰稳定分析

Small Signal Stability Analysis of Power System with Simplified Network Computing Using Power Flow Equations

在电力系统的小干扰稳定分析方法中,电力网络与动态元件的接口方程普遍采用节点电压方程。以往方法在处理负荷时通常采用电压静特性模型且系统的运行方式连续变化,造成状态矩阵的修正计算量庞大。针对这一问题,本文提出了接口方程采用潮流方程进行小干扰稳定分析的方法。在原有动态元件的线性化微分-代数方程的基础上,本文以注入功率为代数向量,并结合线性化处理的网络潮流方程,建立了用于小干扰稳定分析的全系统数学模型,由此得到了新的全系统状态矩阵和电压静特性负荷对全系统状态矩阵的修正。分析表明该状态矩阵具有收缩网络的特点,其修正式具有简化网络计算的优越性。数值仿真验证了该方法的正确性。

In the small signal stability method for power system,nodal voltage equation is usually used to formulate the interface equation of power system and dynamic components. Considering the large calculation amount in the modification of state matrix when dealing with the system whose load is described by a voltage static characteristic model whilethe operation mode is constantly changing,a new method is proposed in this paper,in which power flow equations areadopted in the interface equation to carry out small signal stability analysis. Based on the linear differential equation ofthe original dynamic components,injection power is used as an algebraic vector,and a mathematical system model forthe small signal stability analysis is established with the combination of linearized power flow equations. In this way,anew state matrix for the whole system is obtained together with its modification with respect to the load with voltage stat-ic characteristics. Analyses show that the new state matrix has the characteristics of contract network,and its modifica-tion formula has the advantages of simplified network computing. Numerical simulations verified the proposed method.