Dinorwig Thermal Cycling and Cable Rating

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
National Grid Electricity Transmission

Network Innovation Allowance

Ofgem

01 February 2013

01 January 2017

49 months

£370,000

Power

London

Network Innovation Allowance

Project Contact, National Grid Electricity Transmission

The desired results for this project are to improve the accuracy and understand the effects of thermal cycling on stop joints. This project will be successful if we increase the knowledge and understanding around the thermal cycling effects on stop joints.

The 400kV electricity connection for Dinorwig Power Station over recent years has suffered from poor reliability problems associated with abnormally high Dissolved Gas levels in the cable fluid. These levels have forced NGET to switch out the Dinorwig-Pentir 1 circuit in 2012 resulting in a circuit outage to replace the ‘gassing’ stop joint accruing BSIS costs of circa £150k per day. An identical issue occurred in 2011 on the Dinorwig-Pentir 2 circuit with identification of another ‘gassing’ stop joint. These incidents have prompted an action to probe further into the likely root cause as well as further studies to understand the resultant effects (pertaining to stop joints) from an aspect of thermal cycling. National Grid will install condition monitoring on existing stop joints on the Dinorwig Cable Circuit. This data will be observed and monitored, and then the temperature data will be coupled with system records of circuit load. This merged data will then be used to validate updated Finite Element Analysis models of joint bays and compared to existing methods. This difference (if any) will be then identified and analysed.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above

09/08/18