UKERC EDC: Publications

NIA_NGET0146_CL_2048.pdf

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Abstract:

This document is a closedown report for the project titled 'Assessment of Electronic (analogue and Numeric) Protection equipment end of life mechanisms'.

The scope of the project will establish the techniques and processes to be used on these equipment types. These techniques and processes will be applied to a specific number of relay types to validate the process and evaluate the lives of these specific equipment types. The specific equipment types selected will be those predominantly in service on the transmission network which current policy would require to be replaced in the next 5 years. The establishment of a successful evaluation process for asset life would then be utilised as a research method to evaluate asset lives on other specific equipment types.

The objectives are:

To identify the critical life limiting elements within electronic protection devices.

Establish assessment and testing criteria to determine deterioration mechanisms and rates.

Undertake testing on specific equipment types to establish current and expected deterioration.

Evaluate results of testing to determine asset lives for the equipment types concerned.

Based on these results it will consider and recommend if the life limiting factors can be addressed by methods other than equipment replacement.

Each of the three relay types yielded consistent evaluation results and has demonstrated eligibility for an asset life extension. Based on condition and deterioration observed to date an initial extension of five years for each relay type is proposed. Since the tested relay types continue to perform reliably with no increase in failure rates or component degradation over many years of service, the flat failure-rate trajectory does not forecast any specific end of asset life. The proposal to extend asset life by five years comprises a service life extension of only 15% of the time for which the oldest evaluated unit has already served. The service life extension is further supported by thorough technical evaluation of any failure that occurs during the extended life interval, and re-evaluation of the policy change if any unforeseen failure pattern arises. The process established in this project may be applied to other types of light current equipment with further investigation and development.

This report covers the project's:

Scope

Objectives

Success Criteria

Performance Compared to the Original Project Aims, Objectives and Success Criteria

Required Modifications to the Planned Approach During its Course

Lessons Learnt for Future Projects

Outcomes

Planned Implementation

Other Comments

Publication Year:

2016