Power engineering and trials

The PET workstream’s objective 

The PET workstream’s objective was to establish the technical requirements for an electricity system restoration service – also known as black start. It did this through:  

• detailed analysis of case studies 
• multiple stages of review and testing 
• demonstrating the service’s concept in live trials on SPEN networks. 

Extensive engagement with the energy sector 

The PET workstream engaged with distribution network operators (DNOs) and transmission owners (TOs), as well as other industry stakeholders. It also engaged with DER developers and specialised consultants, including universities and national electrical testing centres.  

The workstream drew on learnings from power system analysis of several distribution restoration zone (DRZ) case study networks. Additionally, it worked with a number of suppliers to develop an automation scheme, called a DRZ controller.  

What did the PET workstream deliver?  

The PET workstream delivered the following outputs: 

Requirements for a distribution restoration zone (DRZ) 

The workstream defined the technical capabilities required for a feasible DRZ. This may incorporate multiple DERs to provide services such as restoring customer demand, energising the network to enhance substation resilience, and ‘bottom-up’ energisation of the transmission network. 

The Final Findings and Proposals report defines the terms ‘anchor DER’ and ‘top-up services’. These describe the capabilities required of DERs and set out what DNOs may need to do to facilitate a distribution restoration zone.

Successful live trials 

The workstream used a range of technology types to prove successful energisation through live trials at Galloway and Chapelcross.  

A prototype DRZ controller 

The workstream defined, developed and factory-tested a prototype DRZ controller.  

The controller was designed to help automate the process of restoring customer supplies in each DRZ island. It then synchronises DRZ islands with each other and the transmission network to support the electricity system restoration process. 

This work was completed in partnership with the organisational, systems and telecoms (OST) workstream.   

Further information 

• Power Engineering and Trials – Demonstration of Black Start from DERs (Live Trials Report) Part 2 - October 2022
• Power Engineering and Trials Demonstration of Black Start from DERs Live Trials Report Part 1 – December 2021
• The Live Trials Stage Podcast Event – April 2021 
• PET Report – Assessment of Power Engineering – Aspects of Black Start from DER – Part 2
• Power Engineering and Trials – Assessment of Power Engineering Aspects of Black Start from DER – Part 1 July 2020
• Power Engineering and Trials – Viability of Restoration from DER Report – July 2019