Analytical Methods for Determination of Stable Operation of IBRs in Future Power System

With growing penetration of power electronics-based renewable energy resources, there are concerns about their impact on the power system stability. To enable safe and reliable power delivery in future power systems with significant contribution from inverter-based-resources (IBRs), development of methods for determining stability and stability margins around different system operating conditions holds significant importance. This paper presents a methodology to assess multiple operating points at which the IBR is expected to operate, identifying points of instability, and subsequently confirming these findings through time-domain simulations. The developed procedure utilizes grid strength assessment metrics, including remaining available MVA and optimal reactive power management, to pinpoint locations that can have potential stability issues at different operating points. Employing the methodology presented here, system planners and operators can determine whether a particular operating point is small-signal stable or not. Based on the result, the operating point can be adjusted to shift the network towards a more stable operating state.