Stability Analysis and Location Optimization Method for Multiconverter Power Systems Based on Nodal Admittance Matrix

This article presents an impedance-based method for stability analysis of multiconverter power systems based on the generalized Nyquist stability criterion. The return-ratio matrix of the system is formulated on the basis of the nodal admittance matrix and output admittance of the converters, which can be applicable for large-scale systems with complicated structure. A modified IEEE 13-bus system is used as the testing system, which shows that the proposed method can be easily implemented for location optimization of the converters. And the participation factors (PFs) of the return-ratio matrix’s critical eigenvalues [which encircle the critical point (−1, <tex-math notation="LaTeX">$0 j$ </tex-math> )] at the instability frequencies are used to identify which converters have significant contributions to the instability, and then guidance for the design of system parameters can be provided. Simulations in PSCAD/EMTDC validate the effectiveness of the proposed stability analysis method.