**1. Introduction**

The right to a healthy and enabling environment is a main principle for all living beings. This is one of the reasons why the world is moving towards an effective policy for managing this sector. The environment is constantly suffering from greenhouse gas emissions, which are mainly generated by fossil fuels. The world must therefore begin a process to manage energy issues as part of a comprehensive and successful strategy. Despite the major energy carriers being fossil fuels and their contribution to environmental pollution, the energy demand is increasing. Renewable energy is a competitive alternative, and their economics has been assessed in comparison with various renewable energy sources as in [1] aside from a regulation strategy suggested in [2,3]. Various studies have accounted for their planning and integration into the distribution grid, as discussed in [4,5]. This is why the world is turning to new energy resources that are promising, socially compatible, renewable, and sustainable. These sources include solar power [6], wind power [7], biomass [8], geothermal power [9], and ocean power [10].

Countries located between altitudes of −40 and +40 have a very high amount of sunshine throughout the year [11]. In addition, observed decreases in rainfall have resulted

**Citation:** Hilali, A.; El Ouanjli, N.; Mahfoud, S.; Al-Sumaiti, A.S.; Mossa, M.A. Optimization of a Solar Water Pumping System in Varying Weather Conditions by a New Hybrid Method Based on Fuzzy Logic and Incremental Conductance. *Energies* **2022**, *15*, 8518. https://doi.org/ 10.3390/en15228518

Academic Editors: Sérgio Cruz and Oscar Barambones

Received: 5 October 2022 Accepted: 1 November 2022 Published: 14 November 2022

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**Copyright:** © 2022 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/).

in insufficient resources available to meet agricultural demands. Therefore, pumped irrigation has become an inevitable necessity. Two approaches are considered to achieve the pumping activity, either by connecting to an electricity source or by using fuels, such as diesel or butane, for pumping. However, the latter alternative is not pollution-free aside from requiring financial resources, raising the production cost. An alternative approach is the use of photovoltaic energy, which is a competitive alternative in terms of being environmentally friendly and is a competing alternative from the economic aspect [12].

The use of solar energy to partially or totally solve the problem of pumping is an option that has existed for a long time. Photovoltaic panels are components of a solar system designed to collect solar energy and convert it into electricity. However, PV systems have low efficiency due to their dependence on weather conditions, including temperature, irradiance, and other system equipment [13]. The generator photovoltaic (GPV) has a nonlinear static current–voltage characteristic of a maximum power point (MPP). This characteristic depends mainly on the level of irradiation, the temperature of the cells, and the aging process [14]. The operating point of a photovoltaic system is very complex to determine. In addition, the load connected to the GPV determines the operating point, which leads to a significant deviation from the maximum power point. The occurrence of multiple irradiance variations can lead to irrecoverable yield decreases, variable power, outages, and even insufficient solar pumping [15].

To ensure optimal operation of the GPV, it is necessary to adjust a solar water pumping system (SWPS) in such a way that the generator is forced to deliver its maximum power. Thanks to a static DC–DC converter, this function is ensured by providing an MPPT control system that acts on the converter's duty cycle, thus ensuring optimal adaptation to the variation of the load characteristic. DC–DC converters are commonly used in renewable energy installations, including photovoltaic panels [16].They are employed to adapt the input voltage to the desired output voltage. In some cases, it is sufficient to lower or raise the output voltage; in other cases, it is better to use a controller that can lower or raise the voltage to achieve optimal energy extraction based on MPPT optimization algorithms [17].

There are numerous MPPT algorithms proposed in the literature to track the maximum power point, which are divided into two categories: (i) typical optimization techniques, including perturbation and observation (P&O) [18], hill climbing (HC) [19], and incremental conductance (INC) [20]. These algorithms are characterized by their simple design and implementation. However, they have low performance in terms of tracking speed, efficiency, and power quality. (ii) Modern optimization techniques are based on artificial intelligence and metaheuristic approaches, including neural networks, ABC-PO [21], genetic algorithms [22], and so on [23]. These algorithms offer better performance and efficiency for PV systems. However, they have drawbacks that lie in the complexity of design, implementation, and very high computational time.

In this paper, a hybrid FL-INC algorithm based on fuzzy logic and incremental technique is developed and applied to the solar pumping system to improve its functioning in terms of efficiency, tracking speed, power quality, steady-state oscillations, complexity, and tracking of the maximum power point under different weather changes. In addition, the benefits of indirect coupling through an adaptation stage composed of a SEPIC converter compared with direct coupling of the system are analyzed to demonstrate the efficiency of such a system. As another contribution, the present work shows a comparative study between the proposed FL-INC algorithm and the P&O and M-INC techniques to confirm improvements related to the pumped water flow for a solar pumping system application.

The remainder of this research article is structured as follows: Section 2 is devoted to the description of the solar pumping system. Section 3 describes the constitution of the solar pumping system. Section 4 discusses the MPPT optimization techniques used. Section 5 presents the analysis of the obtained research results. Section 6 is devoted to a comparative study of the MPPT optimization techniques. Finally, Section 7 presents a conclusion of this work and future perspectives.

#### **2. Description of the Solar Water Pumping System**

Solar pumping system installations typically require the following components: a GPV, a static power converter to improve system efficiency and reliability to optimize the amount of water pumped, and a motor pump assembly. These elements mentioned above are coupled in two ways. As shown in Figure 1a, direct coupling is the basic topology that can be made, in which a motor pump unit is directly connected to the GPV. The main reason for this option is the lack of other electronic devices to control the system, which results in a low-cost solution [23]. However, the direct influence of the coupling on the power delivered by the GPV is reflected by the intersection between the GPV and motor pump characteristics [13]. The main disadvantage of this configuration mode is that it does not allow any regulation of the voltage at the motor terminals, while the transfer of the maximum available power to the GPV is not ensured. In fact, to overcome the latter, an indirect coupling is used, in which a matching stage is inserted between the GPV and the motor pump assembly, as shown in Figure 1b. In fact, this stage acts as an interface between the two equipment and ensures the permanent transfer of maximum power supplied by the generator.

**Figure 1.** Coupling types between the motor pump and the GPV.
