Análise de distorções harmônicas em data centers: da medição em campo ao estudo de acesso à rede básica

Abstract

The accelerated expansion of data centers, driven by the rise of Artificial Intelligence and the growing demand for digital services, has significantly increased electrical energy consumption and intensified concerns regarding the impacts of these facilities on Power Quality (PQ). Due to the non-linear nature of their loads, especially uninterruptible power supply (UPS) systems and frequency inverter-based cooling systems, these facilities act as potential sources of harmonic distortions, which can compromise grid performance at the point of connection. Given this scenario, the present work aims to analyze the harmonic distortions generated by data center operations and evaluate mitigation strategies in light of the access requirements for the Bulk Power System (Rede Básica). The adopted methodology articulates three levels of analysis: field measurements of a real medium-sized facility located in Uberlândia/MG, according to the PRODIST Module 8 guidelines; computational modeling of linear and nonlinear loads in the MATLAB/Simulink environment, based on the measured data; and the access study of a hyperscale complex to the 230 kV Bulk Power System, conducted in the HarmZs software in accordance with ONS Technical Note NT 009/2016 (rev. 03), representing the Internal Network with a Norton equivalent and the External Network using the Geometric Locus of harmonic admittances. Field measurements confirmed an emission profile compatible with 6- and 12-pulse rectifiers, with all PQ indicators within regulatory limits. In the access study, the original configuration showed a violation of the individual limit for the 11th harmonic order at the Point of Common Coupling (PCC). The insertion of a tuned passive filter for this order corrected the initial non-compliance but caused an amplification of the 3rd harmonic order due to a parallel resonance effect. The definitive solution was achieved by installing a second filter tuned to the 3rd order, empirically resized by increasing its power to 10% of the load power (1900 kVAr), which reduced the individual distortion to 0.56%, remaining below the 0.6% limit. It is concluded that the connection of data center complexes to the Bulk Power System is technically viable, provided it is accompanied by properly sized harmonic mitigation measures, and that the filter design must be conducted systemically, considering the global interaction between the facility's reactive elements and the equivalent grid impedance.