Black Start of Coastline Power Networks From Grid-Forming Ship-to-Grid Services

The expansion of electric ships in the transportation sector, along with environmental advantages, has the potential to enhance the resilience and stability of coastline power grids during blackouts or emergencies through ship-to-grid technology. The power grids located in remote coastal and island communities often face high energy costs and are more vulnerable to blackouts due to their increased risk of natural disasters. Ship-to-grid technology offers an innovative localized solution that enables onshore utilities to avoid the need for installing excessive on-land energy storage capacity to enhance stability and resiliency in the coastline power grid. Electric ships can provide a flexible source to restart power to critical facilities such as hospitals and communication networks. In this paper, a comprehensive scheme for integrating ships into the grid system is proposed, which involves a grid-forming control approach through a DC-link connection. The approach employs a droop-based control strategy, current limiter control, and voltage source grid interface to regulate both voltage and frequency at various stages of the coastline power network restoration. The approach is verified using a 4-zone shipboard power system with grid-forming DC-link connection, for black start of a modified IEEE 30-bus test system during a multi-step black start and re-energization process.