Composite Core (ACCC) Inspection

Completed

Other Power and Storage Technologies(Electricity transmission and distribution)

Applied Research and Development

ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering)

Not Cross-cutting

Project Contact
Scottish Hydro Electric Power Distribution plc (SHEPD)

Network Innovation Allowance

Ofgem

01 December 2016

01 January 2018

15 months

£200,000

Power

Scotland

Network Innovation Allowance

Project Contact, Scottish Hydro Electric Power Distribution plc (SHEPD)

Objective(s)The project objectives are: ; To gain an understanding of the effectiveness of the ACCC composite core inspection tool in evaluating the carbon core. ; To develop a fully working prototype with a design fully tested and evaluated for performance. ; To produce a report with details of defects and inspections done with the prototype on defective samples. ; To produce a report with details of training, data capture requirements, certification and requirements for integrating with a travelling inspection device. The project will be considered a success if a prototype is built and fully assessed for deployment readiness, or if learning is gained through the project showing unresolvable issues in the process.

Aluminium Conductor Composite Core (ACCC) consists of a carbon-fibre core wrapped by aluminium strands. This type of arrangement offers a lower weight than in typical conductors typically used on Transmission overhead lines, which tend to have a steel core. In addition, ACCC sags less thereby having the capability to be operated at much higher temperatures without contravening statutory safety clearances. There is growing usage of ACCC around the world and within GB where an increasing number of projects are seeking to increase power flows on Transmission lines without the need to upgrade weight bearing components. When ACCC is used to upgrade lines, less invasive activities are performed and there are less associated costs than would be the case when civil engineering works are needed to reinforce weight bearing components. Currently there is no method to determine the integrity or condition of the core of ACCC overhead lines after or during the installation process which is when it is most vulnerable. This is due to potential issues introduced in transportation, handling or imperfect workmanship. The main concern about carbon-fibre is that defects on it, such as cracks, are almost undetectable. Without confidence about the strength of ACCC cores in service network owners will not be able to leverage its benefits. The project aims to develop a carbon-fibre inspection prototype. This is expected to give the network operators reliable information about the condition of ACCC overhead lines. The tool could potentially be used by manufacturers to detect defects at source or by utilities during and after construction. The project is a technical method to develop a carbon-fibre inspection prototype. This prototype will be a portable device, which has its own power supply and recording processor. The device will be used as an inspection tool during construction or planned maintenance of ACCC strung overhead lines. It is expected to give information about the defects of the carbon-fibre core, which could subsequently propagate into potential failures. Such a tool does not exist at the moment and this may discourage networks from adopting and leveraging the potential benefits of using ACCC on their network infrastructure. The approach will be to use the already existing optical laser technology, which is used with great success in the detection of defects on the carbon-fibre in carbon products such as yachting hulls and masts. The devices currently in the market for doing so are difficult to transport given the size and weight hence the need to develop a prototype of a portable device that can easily be deployed into the field. Where the carbon is not exposed the tool will measure the strain of the core by introducing current and monitoring the changes of the carbon-fibre core. The prototype would be used to assess the condition of the first 20 meters from each dead-end or splice assembly. Later stages of the project will look at developing a specification for integration of the prototype sensing technology with a motorised robot which will be able to inspect the full length of the conductor.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above

09/08/18