Resumo:
The aging of equipment installed in the Electric Power System is a worldwide reality. In Bra zil, large electrical installations such as power plants, transmission lines and substations were
built in the 1960s and 1970s. Therefore, equipment that has not yet been replaced has been in
operation for over 50 years. The Brazilian Electricity Regulatory Agency (ANEEL) establish es the remuneration of companies that operate in the electricity sector through criteria that
include, among others, quality performance indicators for the supply of electricity and the
amount invested by companies, assuming for the power transformer installed in distribution
substations a depreciation rate such that the equipment is considered fully obsolete in 35
years.
The need to replace aging equipment competes with other demands on electricity distributors,
such as the need to expand the system to meet the load growth and to return dividends to in vestors. In this context, companies in the electricity sector have sought to improve the man agement of their assets, through norms and methods that allow a detailed analysis of tech nical, economic and strategic criteria.
This dissertation presents the health index as a relevant metric in asset management, capable
of prioritizing investment needs in the renewal of companies’ power transformer installations.
The proposed work details the creation of this index for substation power transformers, de scribing the necessary data to diagnose the conditions of the internal components (winding,
core, oil and solid insulation), high voltage bushings and on-load tap changer (OLTC), as well
as it presents all the mathematical equations that allow its calculation.
The proposal is applied in a Brazilian electricity distribution company, which adopted the
health index according to the criteria presented in this dissertation to classify its 681 power
transformers, installed in 354 substations. The classification is one of the asset management
tools adopted by the company to provide technical and economic justification for the invest ment plan for the 2023-2027 cycle presented to ANE
