Evaluation of the Impact of IBR on the Frequency Dynamics in the Brazilian Power System

Abstract

In this paper, the impact of inverter-based resources (IBRs) on the frequency dynamics of the Brazilian Interconnected Power System (BIPS) is evaluated. A measurement-based framework is proposed to assess the impact of IBR penetration on the system-wide and regional/local frequency dynamic. The analysis leverages data from a low-voltage wide area monitoring system (WAMS) and publicly available historical generation records from the Brazilian System Operator. A methodology is introduced to extract local frequency fluctuations across regions using a variational mode decomposition (VMD) approach. The findings reveal a continuous degradation in the system-wide frequency and local frequency variations, underscoring the need for enhanced regional monitoring and evaluation metrics to maintain frequency stability in large-scale interconnected systems.