Hardware-in-the-Loop Protection Validation for Dominion Energy Blackstart Operations

This article assesses transformer differential protection and out-of-step blocking (OOSB) schemes during blackstart in Dominion Energy’s system. The protective functions are validated by hardware-in-the-loop (HIL) simulations involving the relay hardware with the configurations deployed on the field. Additionally, we introduce a systematic methodology to generate OOSB testing scenarios based on the analytic linearization of the system dynamical model. Our results show that both protective functions perform satisfactorily despite the weak grid condition of the network during restoration.