Tutorial book on Asset Management - Maintenance and Replacement Strategies at the IEEE PES GM 2007 IR - EE - ETK 2007 : 004

The importance of Equipment Maintenance and Replacement strategies addressing system reliability issues in North American power grids is growing. The reliability of these grids typically comprises lightning and weather induced outages, trees, animals and equipment deterioration. Vegetation management, automation (especially in distribution), insulation coordination and system hardening are common initiatives. However, neither of these address equipment deterioration directly. As the infrastructure is aging (average ages approach 40 years, some equipment categories have appreciable numbers exceeding 55 years) the question really is how long will failure rates stay constant? If they go up due to wear out, how fast will they increase? Can we do something about this right now? Can we for instance maintain more effectively and thereby extending its useful life? Can we apply life extension kits? The answer is; yes, but it depends on the actual business case and what the respective Utilities are already doing. What does it cost in terms of O&M labour and materials to do all of this and what does it buy in terms of deferred capital spending (replacement) and improved system reliability? Similar questions can be raised for equipment replacements going forward. Should we spend more capital to pro-actively replace certain equipment? If so, what equipment and at what rate? How does this affect O&M spending and system reliability? And, more challenging, in light of the other above-mentioned options to improve system reliability, what is the most cost-effective option? This chapter address these issues, the options and will provide practical examples of how utilities deal with project ranking, prioritization and optimization under certain objectives and constraints and uncertainties. 2.