Studies and solutions for fault diagnosis in electric power systems with inverter-based resources

Author(s)

Moisés Junior Batista Borges Davi

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD)
• Defense date: 2025-02-03

Examining board members

Mario Oleskovicz; Denis Vinicius Coury; Karcius Marcelus Colaco Dantas; Silvio Giuseppe Di Santo; Kleber Melo e Silva

• Advisor: Mario Oleskovicz; Felipe Vigolvino Lopes

Abstract

Climate impacts and the accelerated depletion of fossil fuel reserves have highlighted renewable generation as a solution for supplying current and future energy demands. As a result, there has been a massive integration of Inverter-Based Resources (IBRs) into electricity systems in Brazil and worldwide. In this new scenario, the atypical operational characteristics of IBRs have concerned researchers since protection functions and fault diagnosis methodologies were designed based on the behavior of conventional generators, which is now influenced by the presence of IBRs in the system. Given this problem, this Thesis proposes a complete fault diagnosis solution for systems with IBRs, which consists of fault detection, classification, and location methodologies. The disturbance detection methodology combines the potential of the Discrete Wavelet Transform and Mathematical Morphology to create self-adjusting thresholds for decision-making, dispensing any analysis or parameterization by the user. In turn, the proposed fault classification/selection of the phases involved (with or without the involvement of earth) operates based on incremental quantities and self-adjusting thresholds, eliminating the phasor estimation process and enabling faster and more reliable decisions without requiring adjustments by the user. Finally, the multi-method fault location methodology includes a proposed modification of the Takagi zero-sequence method. It significantly reduces errors in this task for systems with IBRs. A representative database of simulations obtained from two power systems with different voltage levels and IBR topologies was considered to validate the proposed methods. The systems and IBRs were modeled using PSCAD/EMTDC software, and additional analyses were performed using MATLAB software. The investigations, proposals, and validations have made it possible to overcome the knowledge boundary on fault diagnosis on transmission lines in systems with IBR. Finally, the complementary contributions of this Thesis are summarized and integrated in the analysis of IBR impacts in protection systems and also in the investigation of machine learning-based methodologies for fault diagnosis in systems with IBRs, providing lessons learned and contributions to the state state-of-the-art in both topics. (AU)

• FAPESP's process: 22/00483-0 - Methodology for faults diagnosis in transmission lines with high penetration of inverter-interfaced wind generators
• Grantee: Moisés Junior Batista Borges Davi
• Support Opportunities: Scholarships in Brazil - Doctorate