ABSTRACT
Aging equipment is undoubtedly the primary cause and effect associated in most people’s minds with the term “Aging Infrastructure.” And while there are other significant factors involved as were summarized in Chapter 1, there is no doubt that aging infrastructures present an incredible challenge largely due to the effects of aging equipment. Aging equipment has high failure rates and requires, proportionally, more inspection and maintenance cost. Often parts and service equipment are hard to come by (and expensive). This chapter looks at equipment aging – what it is, how it impacts the various types of equipment, and how those changes affect the reliability and economy of a power system’s operation. Invariably failure rates increase with age, usually in an exponential manner. But characteristics vary depending on equipment type (aging impacts poles very much differently than say, cable) and conditions of use. Most important to the modern distribution utility is how an aging base of equipment changes the performance (reliability and economy of operation) of the system as a whole, and impacts the quality of customer service. This chapter begins in Section 7.2 with a qualitative look at aging and its impacts on equipment, discussing the different categories of aging impact, and the general characteristics of aging on equipment such as transformers, poles, cables, etc. Section 7.3 then looks at quantitative trends in failure rates as equipment gets older – how and why do failure rates increase? This section raises an interesting concept – what would exact information on when a particular unit of equipment
will fail be worth, and how could a distribution utility utilize that information? Section 7.4 delves into the impact that aging and failure rates have on the installed base of equipment in a utility system and the repercussions on cost and service quality that result. Section 7.5 concludes with a summary of key points.
