含恒功率负载的弱电网线路阻抗稳定区间辨识:阻抗技术

弱电网因其易发生低频振荡和谐波振荡现象而被广泛研究。然而,传统的阻抗方法更注重于线路阻抗稳定运行点的辨识和回比矩阵的稳定裕度,而不能提供具体的线路阻抗稳定区间。因此,文中提出一种基于安全保护映射理论的弱电网线路阻抗稳定区间辨识方法,以求为实际系统规划和相关回稳方法研究提供指导。首先,分别建立交流弱电网的源侧阻抗矩阵和载侧导纳矩阵。然后,对上述互联系统建立稳定禁止区间,并进一步转化为稳定运行区间。其与基于范数的阻抗准则相比,该稳定区间的保守性显著降低。进而,通过镜像、平移和旋转映射互联系统的回比矩阵将线路阻抗稳定区间的求解过程转化为Hurwitz矩阵的辨识问题,并且通过安全保护映射理论直接得到线路阻抗稳定运行区间。最后,通过仿真和实验结果验证该方法的保守性和有效性。

Stability-oriented Line Impedance Domain Assessment for Weak Grids With Constant Power Loads:An Impedance-based Approach

Weak grids are gaining considerable attention since power generation resources are remote from power loads,which results in low-frequency/harmonic oscillation.However,the conventional impedance-based approach pays more attention to the identification of line impedance stable operating points and the stability margin of the return-ratio matrix,but it cannot provide detailed system parameter stability region.Thus,this paper proposed a line impedance stability region analysis method for the weak grid to provide the guidance for practical system planning and related stabilization method researches.Firstly,the source impedance and load admittance matrices for the AC weak grid were separately built.Then,the forbidden region was constructed for the above interconnected system,and it was further transformed into the stability operation region.Compared with the norm-based impedance criteria,the conservatism of the proposed stability region is significantly reduced.Moreover,the solution process of the line impedance stability region was switched as the identification problem regarding Hurwitz matrix through mirror,translation and rotation mapping of the interconnected system return-ratio matrix,and the line impedance stability region was directly obtained by guardian map theory.Eventually,the simulation and experimental results verified the conservatism and effectiveness of the proposed method.