发电机和并联补偿对电压小扰动稳定性的影响

STUDY ON STEADYSTATEVOLTAGESTABILITYCONSIDERING DYNAMICS OFGENERATORSAND SHUNTCOMPENSATORS

利用非线性动力系统分岔理论，研究了发电机各种动态环节对系统电压小扰动稳定性（ＳＳＶＳ）的影响，表明励磁系统对ＳＳＶＳ影响显著，且当计及励磁系统的某些非线性环节（如励磁电压限值）后，可能会完全改变系统的失稳方式；讨论了并联补偿电容器组与慢速励磁系统之间相互作用而产生的负阻尼现象及其规律，这种负阻尼会显著降低系统的传输功率极限，运行中应尽量避免。提出了用合理配置ＳＶＣ来降低这种负阻尼现象的方法，并讨论了ＳＶＣ参数的选择和配置。

This paper studies som e aspects ofsteady state voltage stability (SSVS) of pow er system using the bifurcation theory of nonlinear dynam ic system . First, the influence of param eters and nonlinear com ponents ofgenerator on SSVSis studied. Itis show n thatthe param eters and nonlinearcom ponents ofexciteraffectSSVSstrongly. Then the phenom enon of negative dam ping due to the interaction between shunt capacitor banks and slow exciter system , is discussed, which can decrease the transm ission pow erlim itto a very low level. So itm ustbe avoided in system operation. Finally theeffectofSVC on system stability region isdiscussed, and a m ethod isprovided to decrease such a negative dam ping by appropriate selection ofSVCin shuntcom pensation. This w ork is supported by NationalKey Basic Research SpecialFund (No. G1998020303).