Acta Scientiarum http://periodicos.uem.br/ojs ISSN on-line: 1807-8664 Doi: 10.4025/actascitechnol.v44i1.58660 ELECTRICAL ENGINEERING Acta Scientiarum. Technology, v. 44, e58660, 2022 Grid-connected photovoltaic system to mitigate momentary voltage dip based on the balance between the active and reactive powers Anderson Rodrigo Piccini 1, 2* , Geraldo Caixeta Guimarães 1 , Arthur Costa de Souza 3 , Ana Maria Denardi 2 , Leonardo Rosenthal Caetano Silva 4 and Jaqueline Oliveira Rezende 1 1 Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, Uberlândia, Minas Gerais, Brasil. 2 Instituto Federal de Educação, Ciência e Tecnologia do Paraná, Rua José Felipe Tequinha, 1400, 87703-536, Paranavaí, Paraná, Brasil. 3 Universidade Federal de Itajubá, Itabira, Minas Gerais, Brasil. 4 Instituto Federal de Educação Ciência e Tecnologia de Goiás, Itumbiara, Goiás, Brasil. *Author for correspondence. E-mail: anderson.piccini@ifpr.edu.br ABSTRACT. With a great potential yet to be explored in Brazil, the grid-connected photovoltaic system, besides supplying the active power, can also contribute to improve the voltage level grid providing reactive power. Therefore, this work proposes to use a Grid-Connected Photovoltaic System (GCPVS) equipped with a control that uses the automatic voltage regulator (AVR) to balance the injection of the active and reactive powers, thus softening the short-duration voltage variation, more specifically the momentary voltage dip. For this purpose, the GCPVS was connected in part of a real distribution grid that attend the block 1106 South of Palmas city, state of Tocantins, northern region of Brazil. It is shown that the active and reactive power delivered to the grid can be controlled to help the power quality of the main grid during a disturbance. During a short-circuit situation, the active power is reduced, freeing up space from the inverter capacity for maximum supply of reactive power, in this way, helping the main grid to return to an adequate voltage level. The simulation results show that such voltage profile improvement is possible. Therefore, they confirm that photovoltaic systems, even though considered small, can also provide ancillary services to the low voltage distribution grid during abnormal conditions, adding to the actions normally performed by conventional power plants. Keywords: Short-duration voltage variation; momentary voltage dip; grid-connected photovoltaic system; balance between the active and reactive powers; automatic voltage regulator. Received on April 14, 2021. Accepted on October 1, 2021. Introduction Distributed Generation (DG) can be defined as a source of electricity generation connected directly to the distribution grid, close to the point of consumption, regardless of the source of energy or fuel, the power or the size of the generating unit and, finally, the technology involved (Agência Nacional de Energia Elétrica [ANEEL], 2018a; Instituto Nacional de Eficiência Energética [INEE], 2020). Because of these characteristics, DG continues to gain significant interest among companies and end consumers of electricity around the world. DG technologies have quickly evolved to include ever-lower powers. In this evolution, all the equipment involved, such as measurement, control and command (whose purpose is to articulate the operation of generators) and the eventual control of loads (on/off) must, at the same time, adapt to the systems and energy supply (Albuquerque, Moraes, Guimarães, Sanhueza, & Vaz, 2010; Piccini, Tamashiro, Rodrigues, Guimarães, & Barbosa, 2014; Piccini, Guimarães, Souza, & Denardi, 2021). Among the DG systems, those referred as Renewable Energy (RE) sources (wind, solar, biomass and landfill gas) have aroused great interest, due to their variety, environmental concerns, increased demand for electricity and support for utility grids (Goqo & Davidson, 2018; Kabalcı, 2020). Among the renewable sources, the photovoltaic solar energy has stood out, due to its increasing deployment and market share. As a result of the growing adoption of this resource, the electric distribution Grid-Connected Photovoltaic Systems (GCPVS) is developing at an amazingly fast pace and will soon be a large part of power generation in some regions. Given this fact, there are changes in dynamic behavior and impacts in this distribution grid, where such system has been inserted (Afshari, Moradi, Yang, Farhangi, & Farhangi, 2017; Goqo & Davidson, 2018; Sufyan, Rahim, Eid, & Raihan, 2019).