A Method for Determining the Node Admittance Matrix and System Stability of Wind Turbines Based on Impedance Method

At present, the calculation of node admittance matrix in power system is of great significance in small signal stability analysis. How to verify the correctness of node admittance matrix faces huge challenges, mainly due to the high-order characteristics of power system and the need for recalculation in different states. This article uses impedance method to verify the correctness of the node admittance matrix. Firstly, by calculating the eigenvalues of the aggregated impedance of the power system to determine whether it is consistent with the eigenvalues of the node admittance matrix, the correctness of the proposed model is verified. Then, make a Nyquist plot to preliminarily determine whether the system is stable. Finally, to further verify the stability of the system, a time-domain simulation model was built in Matlab/Simulink to verify whether the frequency of the system approaching steady state is consistent with the calculated critical stable characteristic values.