Black Start Coordination Using a Grid-Forming Load

This paper proposes a black start coordination using a grid-forming (GFM) control implemented on a controllable load. In traditional black start scenarios, the primary generator maintains voltage-source characteristics indefinitely. However, this research explores a transitionary architecture where a hybrid control renewable energy source (RES) provides a "primitive," fixed-frequency reference only during the initial bus energization. Once the 33 kV network nominal voltage and the active power setpoint of the load have been reached, the RES soft-switches to grid-following (GFL) mode, handing off the voltage-source-forming responsibility solely to the GFM load (GFM-L). This study evaluates the proposed control scheme across several black start challenges. These include managing resistive and nonlinear diode rectifier load connections, as well as transformer energization and synchronization and reconnection to a 110 kV network. Simulation results utilizing a 4 MW controllable load, 2 MW RES generator and 0.5 MW non-controllable loads demonstrate the ability of the GFM-L to achieve a stable and robust steady state. In this state, the GFM-L actively dictates the voltage and frequency of the black start island and adapts to the additional loads through power balancing. The GFM-L also demonstrates the ability to handle inrush currents from the transformer and timely grid synchronization and reconnection. This architecture provides a resilient solution for black starting remote networks, ensuring that decentralized resources can provide the necessary inertia and damping to support the system as the primary generation shifts to an injection-only GFL state.