Thermal stress analysis of distribution transformers considering reverse power flow

• Grant number: 26/10525-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2026
• End date: July 31, 2027
• Field of knowledge: Engineering - Electrical Engineering - Power Systems
• Principal Investigator: Madson Cortes de Almeida
• Grantee: Kenneth Ernesto Quimi Suarez
• Host Institution: Faculdade de Engenharia Elétrica e de Computação (FEEC). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 21/11380-5 - CPTEn - São Paulo Center for the Study of Energy Transition, AP.CCD

Abstract

The energy transition and the modernization of distribution systems have driven the adoption of Grid Edge Technologies (GETs), with particular emphasis on the rapid increase in photovoltaic (PV) generation penetration. Although these technologies promote the 3Ds concept (decentralization, digitalization, and decarbonization), their integration has significantly increased the complexity of planning and asset management. Among the most critical assets in this context are distribution transformers, which interface between medium-voltage systems and low-voltage consumers. Despite their relevance, these typically low-cost assets operate with limited monitoring due to technical and economic constraints, imposing substantial challenges for the development of consistent assessment methodologies. In scenarios with high PV penetration, these challenges are further amplified by the variability and uncertainty associated with active power injection from PV systems, combined with the increased intensity and frequency of extreme weather events such as heat waves, which raise thermal stress and accelerate equipment aging.In this context, this master's project proposes the development of a framework for active and cost-effective management of distribution transformers, focusing on scenarios characterized by low data availability. First, the study integrates analytical and statistical methods for equipment assessment, explicitly incorporating the impact of ambient temperature and PV generation on operating conditions. This step, developed from actual measurements, constitutes the main modeling contribution by systematically quantifying the effects of these variables on transformer aging. Next, based on the statistical characterization and the obtained results, performance indicators specifically designed for management and planning applications under data-limited scenarios will be developed, representing a methodological contribution aimed at the practical operationalization of the analyses.Finally, the core objective is to propose robust assessment and planning strategies that can be effectively adopted by Brazilian distribution utilities, enabling the mitigation of premature asset degradation under new operational dynamics. The feasibility and effectiveness of the proposed methodologies are validated using high-resolution data from more than 300 distribution transformers installed at the University of Campinas (UNICAMP), together with a database from a Brazilian utility covering over 200,000 units. (AU)