Feb 2016
Electricity Distribution
Optimising Oil Regeneration for Transformers
Feb 2016
Feb 2022
Electricity North West Limited
Electricity North West Innovation Team
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Network Innovation Allowance
Asset Management and Transformers
Previous research carried out under an IFI project suggested that oil regeneration carried out in a window at the end or near the end of a transformers nominal life would extend life by approximately 10 years. The First Tier project deployed online monitoring equipment at five sites where the oil regeneration technique was used.

The NIA project will build on this research by exploring the optimum point to apply oil regeneration to a transformer fleet. It is acknowledged that the life of oil impregnated paper insulation determines the maximum potential life of a transformer, although other factors may cause it to fail earlier. This project scope will aim to determine if mid life oil regeneration can reduce the rate of paper degradation, and thereby further extend the lifespan of the transformer compared to oil regeneration at end of life.

For this project, ten 33kV paired transformers and three 132kV paired transformers (13 sites, 26 transformers) which are at various stages of their design life will be identified.

At each site, only one of the transformers will undergo oil regeneration. Online monitoring equipment will be installed on both transformers at each site to allow comparison of their oil condition and to determine the theoretical life extension over time. These results will be fed into the previously funded data visualisation software to allow consistent comparison.

Electricity North West will work closely with industry experts to validate the data and calibrate the life extension results.

The project will allow Electricity North West to develop its understanding of the effects of life extension on transformer failure modes and maintenance requirements and to identify the optimum window for oil regeneration in the life cycle of transformers.

This project is split into three distinct phases:

Phase 1  Research into and design / sourcing  of an oil regeneration unit to carry out the oil regeneration at the 13 sites
This phase to be completed by September 2016

Phase 2 implement  Oil regeneration at 13 mid life transformer sites and install condition monitoring equipment
This phase to be completed by August 2017

Phase 3  is the data analysis and optimisation of the oil regeneration practice
This phase to be completed by February 2022.

Specification and sourcing of oil regeneration unit capable of delivering the required oil quality in a controlled manner.

Complete oil regeneration and condition monitoring equipment at 13 transformer sites at mid life

Data acquisition, analysis and validation to identify the optimum point of oil regeneration in a transformer life cycle