Power-Swing Blocking Scheme Based on Continuous and Higher-Order Incremental Quantities for Systems with Inverter-Based Resources
Conventional power-swing blocking (PSB) schemes for distance protection face new and emerging challenges as the penetration levels of inverter-based resources (IBRs) increase. Several papers highlight interoperability issues concerning faster power swings and unconventional impedance trajectories. Revised relay settings are proposed in attempts to deal with the problems. However, the blinder-based PSB methodology suffers from being dependent on the speed of the apparent impedance trajectory over the tiny region between the blinders, making it difficult to distinguish between fast swings and faults. Moreover, blinders have the inherent limitation that they cannot operate if the measured impedance is inside the blinders when the fault is cleared and immediately enters the distance zones during the first swing cycle - an issue often overlooked in the current literature. This paper proposes a novel PSB scheme based on higher-order incremental quantities (IQs) for difficult swing scenarios with IBRs and synchronous generators (SGs). PSCAD/EMTDC simulations of an SG and an implemented grid-forming (GFM) inverter validate its superior performance compared to conventional dual-blinder PSB schemes. The impacts of GFM inverters on the impedance measured by distance relays during the fault-to-swing transition and first power swing cycle are also discussed.