Contents lists available at ScienceDirect Electrical Power and Energy Systems journal homepage: www.elsevier.com/locate/ijepes Distributed generation integrating a photovoltaic-based system with a single- to three-phase UPQC applied to rural or remote areas supplied by single-phase electrical power Guilherme Masquetti Pelz a , Sergio Augusto Oliveira da Silva b, ⁎ , Leonardo Poltronieri Sampaio b a Federal Institute of Paraná – IFPR, Av. Cívica, 475, Assis Chateaubriand PR, Brazil b Federal University of Technology – UTFPR-CP, Av. Alberto Carazzai, 1640 Cornélio Procópio, PR, Brazil ARTICLE INFO Keywords: Power quality Photovoltaic distributed generation system Unified power quality conditioner Rural or remote areas ABSTRACT This paper presents a distributed generation (DG) system integrating a photovoltaic (PV) system with a 1-Phase to 3-Phase unified power quality conditioner (UPQC-1PH-3PH). The system named DG-UPQC-1PH-3PH injects into the grid the energy produced from a PV array, contributing to feed loads connected to a local three-phase four-wire electrical system, to attend consumers of rural and/or remote areas supplied by single-phase utility. Besides the injection of active power into the grid, the DG-UPQC-1PH-3PH improves power quality indicators, such as voltage sags/swells, grid voltage harmonics, and power factor. Multi-resonant state-feedback controllers are employed to ensure sinusoidal grid current and load voltages, while an effective PV array voltage control is achieved by using a multi-loop proportional-integral controller. Since the DG-UPQC-1PH-3PH inverters handle the power produced by the PV system plus those demanded by the load, the converters sizing must be carefully performed. Thus, curves that allow the sizing of the power converters based on the power flow through the converters are presented. The static performance is experimentally tested considering several operation condi- tions involving the utility grid voltage, load and energy produced by the PV array, while its dynamic behavior is evaluated when the PV array is subjected to abrupt solar irradiation changes. 1. Introduction Nowadays, serious socioeconomic problems and environmental impacts caused by the construction of new and large power plants (hydroelectric and nuclear), as well as the construction of power station based on fossil fuels (coal, oil, natural gas and others), have prompted governments and researchers worldwide to seek other solutions and strategies to meet growing energy demand. In this context, the gen- eration of electricity from alternative and renewable sources has played an important role to increase the supply of energy in a sustainable way. As a result, besides the reduction of aggressive impacts on the en- vironment, this scenario allows increasing diversification of the energy matrix inserted in the current context of electrical energy generation. In this context, distributed generation systems (DGS) that make use of renewable energy sources (RES), such as solar and wind, have arisen as an important and modern solution to be integrated to the conven- tional power generation systems [1]. Distributed generation systems have been largely employed in both urban and rural areas [2–4]. On the other hand, due to the emerging proliferation of RES, the use of DGS in rural areas has become more and more popular [5–9]. Although the main purpose of DGS is the injection of active energy into the utility grid, their multifunctionalities can be expanded by including active power-line conditioning purposes [10–15]. In this case, besides production of energy, integrated DGS can also perform, simultaneously, active power-line compensation and, hence, contribute to improve power quality (PQ) indicators [16]. For this intention, distributed generation systems operating integrated to shunt active power filters (APF) [10–12], as well as unified power quality conditioners (UPQC) [13–15] have been proposed. This paper proposes a DGS involving the integration of a photo- voltaic (PV) system with a single- to three-phase unified power quality conditioner (UPQC-1PH-3PH) [17], generating the system called DG- UPQC-1PH-3PH. This multifunctional system is indicated to feed, with high PQ, single- and three-phase loads in rural or/and remote areas where, for economic reasons, only single-phase utility grids are avail- able. Specifically, the mentioned system can also be indicated to be employed in areas where single-wire earth return (SWER) distribution system is adopted as electrical power supply. It can be emphasized that https://doi.org/10.1016/j.ijepes.2019.105673 Received 17 May 2019; Received in revised form 27 August 2019; Accepted 29 October 2019 ⁎ Corresponding author. E-mail address: augus@utfpr.edu.br (S.A.O. da Silva). Electrical Power and Energy Systems 117 (2020) 105673 0142-0615/ © 2019 Elsevier Ltd. All rights reserved. T