Citation: Say, G.; Hosseini, S.H.; Esmaili, P. Hybrid Source Multi-Port Quasi-Z-Source Converter with Fuzzy-Logic-Based Energy Management. Energies 2023, 16, 4801. https://doi.org/10.3390/en16124801 Academic Editors: Omar Abdel- Rahim, Sherif Dabour and Wesam Rohouma Received: 12 May 2023 Revised: 6 June 2023 Accepted: 12 June 2023 Published: 19 June 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Article Hybrid Source Multi-Port Quasi-Z-Source Converter with Fuzzy-Logic-Based Energy Management Gorkem Say 1 , Seyed Hossein Hosseini 1,2, * and Parvaneh Esmaili 3 1 Engineering Faculty, North Cyprus, Mersin 10, 99138 Nicosia, Turkey; gorkem.say@neu.edu.tr 2 Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz 51666-16471, Iran 3 Department of Electrical and Electronics Engineering, Cyprus International University, North Cyprus, Mersin 19, 99138 Nicosia, Turkey; pesmaili@ciu.edu.tr * Correspondence: hosseini@tabrizu.ac.ir Abstract: In this paper, a fuzzy-logic-based energy management system and a multi-port quasi-z- source converter that utilizes hybrid renewable energy sources are proposed. The system ensures that each energy source module can be used individually by employing fuzzy logic to define the power modes. This approach also helps to prevent switching losses resulting from the extra switching of the source modules. In addition, the proposed energy management does not have a mathematical model, so its applicability is simple, and it is suitable for different multiple-input topologies. The Mamdani fuzzy inference system can be designed to capture the nonlinear behavior of the system owing to linguistic rules. Moreover, the switching losses of the multiport modules were significantly reduced by adopting the quasi-z-source network to the end of the multiport converter. Furthermore, different errors, such as the root mean square error (RMSE), average squared error (ASE), average absolute error (AAE), average time-weighted absolute error (ATWAE), tracking error (TE), and unscaled mean bounded relative absolute error (UMBRAE), were applied to evaluate the fuzzy logic performance from different perspectives. The simulation results were obtained using MATLAB Simulink, and the experimental results were obtained by connecting the circuit to MATLAB Simulink using an Arduino Due. Keywords: energy management; quasi-z-source; fuzzy logic; DC-DC converter 1. Introduction Over the past two decades, renewable energy sources have gained significant impor- tance due to the energy crisis, wars, and environmental factors. Consequently, sustainable systems are required in every industry. Although renewable sources have low levels of output power, different sources can be connected to boost the output power. Multiple input converters have the ability to connect more than one power source to each other. In some specific applications, it is not sufficient to connect multiple sources together, and a direct power flow of each source is required to manage energy circulation under certain conditions. For instance, the power output of a photovoltaic (PV) array is decreased under dark conditions, and it is necessary to add another power source to meet the load demand. Source type is another parameter to consider. Numerous types of multiple-input converters have been reported in the literature. In [1], the authors explained the combi- nations and rules of multiple-input converters. Different connection methods for several types of sources are presented in this paper. Some basic rules, such as parallel voltage sources, cannot be connected to each other if the voltage levels are different. Furthermore, for some specific converters, more than one source cannot simultaneously supply power. Nejabathkhah proposed a hybrid input source connected via a novel three-input DC-DC converter [2]. The sources could supply power simultaneously, and a battery could be connected as a source to provide bidirectional power flow. A small-signal model was used to control the sources. In [3], multiple inputs were connected via switches to the load using coupled inductors, and the circuit configuration was simple compared to other Energies 2023, 16, 4801. https://doi.org/10.3390/en16124801 https://www.mdpi.com/journal/energies