Transformer & System Reliability

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 October 2010

01 April 2014

42 months

£275,000

Power

London

Network Innovation Allowance

Project Contact, National Grid Electricity Transmission

This project will deliver a methodology for assessing the maintenance and replacement strategies for transformer replacement against system reliability requirements. In particular the derivation of transformer replacement priority from asset health index and perceived system criticality can be greatly refined using a detailed knowledge of transformer failure modes (common mode, sympathetic and hidden failures). The availability of such a methodology will ensure an optimum and justifiable prioritisation of transformer replacement maintenance. This project will be a success if we can understand the issue of transformer & system reliability in greater detail, or provide reasons & understanding as to why this is not possible.

At present the risk and criticality approach to transformer maintenance and replacement is based on a relatively crude 3 point scale of critically and a matrix. This method may be capable of improvement if a real network model is used together with an understanding of possible interactions between failures. Generally a transformer outage is manageable, but two or more simultaneous outages on certain parts of the network could have severe consequences. Identifying these situations and the sensitivity to linked failures is important for the correct and timely replacement of the most critical units. The project will employ two PhD students at the University of Manchester working closely together. One in the transformers group under Prof Wang focusing on the development of an asset health index to include probabilities of linked failures and one in the systems group under Prof Milanovic on incorporating the asset health index and other transformer health dimensions into an assessment of network reliability rates and deriving criticality indices. Year One - Network model including topology and running arrangement for London using real conditions data including trips, breaker fail etc. including load dependant sympathetic and hidden failure coefficients. Report into reliability under intact and outage conditions. Year two - Criticality and sensitivity studies of model to parameters such as temperature, transformer condition, transformer design, cooling etc. and protection reliability. Year three - System reliability sensitivity to replacement policy, maintenance policy and network configuration (optimizing network configuration is out of scope but examining the effect of different connection topologies may be possible).Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above

17/12/18