Resonance Stability Analysis Based on Impedance Network for Large-Scale Wind Power Bases Considering Frequency Coupling Characteristic

With the increasing penetration rate of renewable energy in the power system, the unstable issues due to the resonance may emerge. The s-domain nodal admittance matrix method is an effective method to analyze the resonance stability of system. While the latest research of impedance modeling shows that there exists frequency coupling characteristic in renewable power generation systems, for which the method should be further investigated to take the frequency coupling into consideration. In this paper, the s-domain nodal admittance matrix method is introduced briefly. The impedance network based on the multi-in multi-out (MIMO) impedance model considering frequency coupling is established. And then the s-domain nodal admittance matrix considering frequency coupling is derived in detail. Taking the 10-node system with 4 wind farms as an example, this paper compares the analytical results using the s-domain nodal admittance matrix method with and without considering frequency coupling characteristic, and proves the necessity to add frequency coupling into the s-domain nodal admittance matrix in the stability analysis. And by calculating the participation factor matrix, the effectiveness of s-domain nodal admittance matrix method with considering frequency coupling is verified in the simulation.