Modeling and Reliability Assessment of DC Bus Capacitors for Photovoltaic Inverters

• Grant number: 24/21085-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2025
• End date: February 28, 2029
• Field of knowledge: Engineering - Electrical Engineering - Industrial Electronics, Electronic Systems and Controls
• Principal Investigator: Tárcio André dos Santos Barros
• Grantee: Andressa Mara Menezes Alexandre
• 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 scope of this doctoral research project involves developing strategies to improve the reliability of DC bus capacitors in photovoltaic inverters. DC bus capacitors are indicated in the literature as components where strategies for extending inverter lifespan can be most effectively applied, given that they are the weakest link in the device. Capacitor stress occurs primarily due to high average temperatures, and for this reason, thermoelectric modeling of the capacitor is a crucial step in the component's reliability analysis. This project proposes to develop an algorithm to determine the optimal combination of capacitors from the most commonly used technologies (electrolytic, film, and ceramic) on the DC bus, maximizing reliability, performance, efficiency, and cost. Additionally, it aims to implement a multi-objective model based on mathematical reliability analyses and develop a real-time capacitor lifespan monitoring system, using integrated sensors from the inverter itself to minimize costs. This proposal also presents a brief literature review and some preliminary results obtained during the candidate's master's degree. The goal is to demonstrate the feasibility of carrying out the doctoral proposal, considering the experience gained by the candidate through in-depth study conducted during the master's program. (AU)