Case Study

Earthing of Step-Up Transformers

Distribution network operators (DNOs) maintain and operate extensive overhead line networks. During large-scale events such as storms, these lines can develop faults caused by damage, leading to outages for many people.

 

To restore their power, DNOs temporarily re-energise these sections of overhead lines using generators whilst faults are repaired. However, this can be time-consuming and difficult to deploy, requiring the use of many generators and complicated by some ground conditions preventing effective earthing. 

 

DNOs have previously considered an alternative method of earthing to facilitate power restoration, however this approach has not yet been sufficiently investigated.


The Solution

The project will develop and test a high voltage (HV) inversion unit incorporating 'impedance earthing'. This unit will enable re-energisation of the HV network using a single low voltage (LV) generator and step-up transformer, allowing DNOs to restore power to customers more efficiently.

 

Currently, modelling is taking place to predict the behaviour of the HV inversion unit under various fault conditions. This will determine the theoretical safety and feasibility of this new system. 

 

If this modelling proves successful, the system will be tested using the facilities at the Power Networks Demonstration Centre in Scotland. An existing inversion unit (provided by UKPN), will be adapted to utilise impedance earthing. This testing will establish whether the practical behaviour of the unit aligns with the predictions made during modelling, ensuring safe and reliable operation of the system.

 

Following practical testing, Threepwood Consulting will analyse the results from the modelling and testing stages to produce a high-level specification for the HV inversion unit 


Partners

The EIC are facilitating a NIA funded collaborative project between Northern Powergrid, SP Energy Networks, UK Power Networks and Threepwood Consulting Ltd.

 

This collaboration between multiple stakeholders and a small innovator is enabling the development of this solution from TRL3 to TRL7. When the project is complete, each network will be able to tailor the solution to meet their individual requirements.

 

When deployed into business as usual (BAU), the solution will provide significant benefits by increasing the networks' ability to restore power to many customers during outages.


The Project

The project will focus on three primary areas:

 

1. Theoretical Modelling: To determine the theoretical safety and feasibility of reenergising the HV network using impedance earthing

2. Practical Testing: To establish whether the theoretical modelling has produced reliable results that align with the use of the HV inversion unit in practice

3. Analysis & Reporting: To compare the results from modelling and practical tests in order to produce a high-level specification for the unit. 

 

New Learning

Understanding the safety and feasibility of implementing impedance earthing to reenergise the HV network.


New Steps

Following completion of this project, Threepwood will produce a draft technical specification for the inversion unit required to conduct impedance earthing. This will include essential manufacturing parameters, allowing each DNO to tailor the solution to meet their specific needs. 


The implementation of the new earthing system could enable a more rapid deployment of temporary generation in the event of faults or routine work. Presently, the only approved method can require additional site work to connect the generator. This additional time can delay critical supply restoration to customers in often remote parts of our network.

The Project

Live field trials demonstrated various benefits for network partners, including reduced operational expenditure (OPEX). One trial conducted on a sample section of the gas distribution network in the north of England demonstrated that LeakVISION reduced the overall time required to locate and repair multiple gas escapes, minimising disruption to customers.

As part of the SIF funded project, a trial was completed in a live hydrogen pipeline to assess the device’s functionality and its capability to safely detect leaks. The trial proved successful, providing confirmation that both the deployment and retrieval approach for the device are secure.

Streetworks SGN
  • The successful implementation of a live thermal imaging robotic system within an operational gas distribution network. 

 

  • The system potentially could identify specific ‘areas of interest’ that require remediation. 

 

  • The system has future capability to guide more agile asset investment decisions. 

 

  • A robotic device that uses a heating element to warm-up flowing gas, in a live distribution network, safely and without incident.  

 

  • Identification of design improvements for field operations. 
Streetworks SGN

The Impact

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Customer Service

Minimised disruptions from excavations to assess pipes in difficult to reach places. 

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Societal

Reductions in the number of excavations and faster repair times.

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Environmental

Reductions in the volume of gas vented to the atmosphere during complex-to-locate gas escapes.  

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Operational

A reduced number of excavations will lead to improved safety and will result in fewer injuries to operatives. 

The Project

The aim of StreetScore Phase 2 project was to improve the accessibility and experience of street works for customers in vulnerable situations and the wider public. The focus was on prototyping and validating concepts that could minimise disruptions experienced during street works, before potentially undertaking further developmental and testing activities that facilitates the transition to Business as Usual (BAU) deployment(s).

Streetworks SGN

Workshops were also held to facilitate active engagement between network operators and key stakeholders, such as community groups, charities and advocacy groups. These sessions allowed network operators to develop a greater understanding of the challenges faced by customers in vulnerable situations and provided valuable insights into how customers adapt their behaviours and lifestyle around street works. The feedback gathered has also helped to inform the shortlisting of potential prototypes and concepts for future development.

Streetworks SGN

The Impact

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Customers

Improvements in accessibility and safety around street works, particularly for customers in vulnerable situations.

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Community engagement

Improved engagement between network operators and third parties like community groups and charities.

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Health and safety

Potential to reduce the number of incidents for customers when navigating street works. Learnings from the project have also enabled recommendations for changes or updates to existing regulations.

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Financial

Improved guidance in working around street works thus reducing instances of fines for networks.

The Impact

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Customers

Improvements in accessibility and safety around street works, particularly for customers in vulnerable situations.

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Community engagement

Improved engagement between network operators and third parties like community groups and charities.

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Health and safety

Potential to reduce the number of incidents for customers when navigating street works.

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Financial

Improved guidance in working around street works thus reducing instances of fines for networks.

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Access to the latest opportunities in the industry

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Funding support and guidance

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Connect and collaborate with innovators in the industry

The EIC Hub dashboard

Sign up to our energy innovation hub to take advantage of the benefits and see our innovation opportunities