Revisiting Power Swing Blocking Schemes for Future Power Systems with High Penetration of Inverter Based Resources

The deployment of large-scale renewable energy sources as a part of the transformation to green energy has led to significant changes in the control and operation of power system networks. Renewable energy sources (RES) like solar PV arrays and wind turbines are connected to the power grid through power electronics converters, which do not inherently contribute to system inertia and result in the reduction of total inertia in the power system to a greater extent. In this paper, we review the effect of penetration of inverter-based resources (IBR) on the legacy power swing blocking (PSB) schemes. A mathematical analysis is done to find the relationship between system inertia using the inertia distribution index (IDI) and the rate of change of impedance (ROCI) at the relay locations. Dynamic simulation is performed on the IEEE-9 Bus system to evaluate the performance of traditional PSB schemes in the presence of IBR. The results indicate that the setting of conventional PSB schemes will be more difficult in the presence of high IBR penetration. Furthermore, a possible way to identify vulnerable PSB relays is investigated based on the correlation information between IDI and ROCI.