Substation power transformer risk management: Predictive methodology based on reliability centered maintenance data

The main objective of this article is to present details of a methodology for prioritizing actions in predictive maintenance substation equipment, applied to Power Transformers, which are responsible for the income revenue of energy companies (generation, transmission and distribution). This is one first immersion on the failure analysis and risk management with optimal use of predictive maintenance, to reduce or eliminate transformer outages. Using statistical concepts, this proposal goes through various stages of application, and addresses power transformer differences (generation, transmission and distribution), aspects of life cycle, operation, maintenance, aging, depreciation, aspects of reliability, risk of failure and effectiveness of predictive techniques. The basic process concept lays on stratification and consolidation of data from CIGRÉ Brazilian Working Group-Reliability Centered Maintenance, combined with historical information, taking also into account the diagnosis on equipment condition. Aiming greater visibility simulations is also presented using the methodology as exemplification for different characteristics of power transformers. Conclusions indicated that each company power transformer needs its own prioritization criteria, depending on the particularities of operation and maintenance history.