考虑励磁顶值与PSS的混沌和分岔现象

THE CHAOTIC AND BIFURCATION PHENOMENA CONSIDERING POWER SYSTEMSEXCITATION LIMIT AND PSS

电力系统中的混沌对传统的稳定分析和安全控制而言 ,是一个巨大的挑战。文中研究了发电机励磁顶值和 PSS回路对电力系统的振荡失稳和混沌现象的影响。研究表明 ,当计及励磁顶值极限时 ,或在 PSS参数配置合理情况下 ,可能导致系统 Hopf分岔 (HB)现象不出现或 HB点与鞍—节分岔 (SNB)点十分接近。由于在小扰动稳定框架下 ,HB出现是混沌产生的前提 ,HB不能出现时 ,混沌现象也将消失。合理配置 PSS参数 ,可为系统提供正阻尼 ,从而能够显著抑制 HB及混沌现象的产生。

Chaos in power systems is a big challenge to the conventional stability study and security control.In this paper, effects of hard lim it of the excitation and the loop of power system stabilizer PSS to the system oscillatory instability and chaos are studied.The research shows that when the lim it of the excitation is considered,or the parameters of PSS are adjusted properly,som e Hopf bifurcation HB m ay be disappeared or very close to the system saddle node bifurcation SNB .In sm all signal stability study the occurrence of HB is a precondition of the existing of chaos.If HB cannotoccur,the chaos will be disappeared.When appropriately adjusting PSS,the occurrence of the Hopf bifurcation and chaos can be prevented through generating a positive electrical m agnetic torque damping.The research in this paper is also a beneficial attem pt to find some m easures to prevent the oscillatory instability and chaos in power systems.