The role of asset and network resilience in electricity system restoration 'black start'

The UK electricity network operates under a state of dynamic equilibrium between load and generation. However, rare disturbances can lead to total or widespread loss of the network, a risk identified on the UK National Risk Register[1]. Recovery from such a state, known as “Electricity System Restoration (ESR)” or ‘Black Start’, is critical to mitigating widespread impacts on healthcare, communication, transport, and other essential services. To ensure timely network re-energisation, GB Distribution Network Operators (DNOs) aim for a resilience standard of up to 5 days. This resilience framework encompasses Control, Asset, Operational, and System Resilience. This paper focuses on the pivotal role of Asset Resilience and its importance in enabling Distributed Restart Zones (DRZs). It examines challenges, such as the high DC loads of modern protection and control systems, limiting practical battery backup duration. Solutions such as intelligent battery disconnection systems, strategic backup generators, and resilient telecommunications are explored. Prioritising these aspects within DRZs is essential for facilitating distributed generation integration and supporting rapid system restoration. The paper uses the PB Design Black Start controller as an example of modern asset resilience measures.