Placing Grid-Forming Controlled Converters To Enhance Power Systems Small Signal Stability

The reduction of system strength, driven by the integration of Power Electronic Interfaced Resources (PEIR), challenges Small-Signal Stability (SSS) in modern power systems. The deployment of Grid-Forming (GFM) control is widely recognized as a potential mitigation measure. This work proposes a stability-oriented methodology for the optimal placement and minimal sizing of GFM solutions. It introduces an iterative approach based on identifying system weak points using the Frequency Averaged Grid Impedance (FAGI) metric and evaluating stability via the novel Modal non-Passivity Index (MnPI), compatible with black-box models. The methodology determines critical GFM capacity thresholds, ensuring sufficient yet minimal GFM deployment. Time-domain simulations on a benchmark inspired by the northern French transmission system validate the effectiveness of the proposed approach across various scenarios, highlighting its adaptability to different deployment strategies and the evolution of system needs.