考虑饱和环节影响的电力系统小扰动稳定域

Power System Small Signal Stability Region with Saturation Element Considered

同步发电机励磁系统由于受物理结构限制,励磁电压的输出含有饱和环节(限幅环节),其具有非线性特征。针对计及励磁饱和环节的最优励磁控制系统,提出了以椭球吸引域体积为指标确定小扰动稳定域边界的新算法,计算了定义在注入空间的小扰动稳定域。研究表明:当椭球吸引域体积指标较小,即可镇定的扰动较小时,获得的小扰动稳定域与采用Hopf分岔获得的小扰动稳定域基本相同;当椭球吸引域体积指标较大,即可镇定的扰动较大时,其小扰动稳定域将减小。该方法可将小扰动稳定域大小与可镇定的扰动大小建立联系,因此扩展了小扰动稳定域的研究范畴。

Because of the limitations imposed by the physical structure of the excitation systems of synchronous generators, the voltage output of the system has saturation elements （magnitude modulation element）. This effect inevitably introduces nonlinear characteristics to the excitation voltage output. A novel approach is presented to determine the boundary of the small signal stability region （SSSR） using the volume of the ellipsoidal region of attraction （RA） as the criteria in linear optimal excitation control （LOEC） system with the saturation element. The SSSR defined in injection space is studied using the proposed method. Results demonstrate that the SSSR calculated based on the proposed algorithm is approximately equal to the one obtained using Hopf bifurcation theory when the criteria of RA or the stabilized disturbance is very small, and the proposed algorithm gets smaller SSSR when the criteria of RA or the stabilized disturbance is enlarged. These results show that SSSR may consider the disturbance, which enlarges the facet of studies on SSSR.