1. Introduction
Over the last few decades, in response to the challenges posed by global warming, and the diminishing availability of traditional fossil fuels, there has been a growing emphasis on the usage of renewable energy resources (RERs) [
1,
2]. According to the projections made by the International Renewable Energy Agency, it is anticipated that RERs will account for around 85% of the total energy generated in the year 2050 [
3]. Among these RERs, solar PV systems are the second most utilized worldwide, following wind resources [
4]. Furthermore, there is a targeted projection that solar energy will account for 20% of the overall energy production by the year 2050 [
3]. In the contemporary period, numerous investments have been made in the field of renewable energy, particularly in the solar power sector. One notable example is the Benban Solar Park, located in Egypt, which boasts a significant capacity of 1.8 GW for photovoltaic power plants [
5].
In this context, several challenges have emerged, necessitating a thorough analysis and precise resolution to enhance the efficacy of the solar PV systems. Hence, to boost the effectiveness of these systems prior to their installation, it is imperative to employ appropriate mathematical models that can efficiently simulate their performance under various operational circumstances.
In the literature, it is common to find three distinct circuit models for solar PV cells that are considered similar. The first model has one diode and is known as the single-diode PV model (SDPVM) [
6,
7,
8,
9,
10,
11,
12,
13,
14]. It is the most utilized solar PV model and is quite simple, as it has only five parameters. The second model contains two diodes and is called the double-diode PV model (DDPVM) [
6,
7,
8,
9,
10,
11,
13,
14,
15,
16]. In this model, the parameters are increased by two because of the additional diode. The additional parameters made the formulation more complicated but at the same time more accurate. Finally, the third model has three diodes and is known as the triple-diode PV model (TDPVM) [
4,
17,
18,
19,
20,
21]. This model is the most complicated and accurate model, as it has nine parameters.
M. S. Ismail et al., in 2013, presented a study on the characterization and optimization of photovoltaic (PV) panel model parameters using a genetic algorithm [
22]. While the paper provides valuable insights and contributions, it also has the potential drawbacks of a limited sample size, lack of comparative analysis, and insufficient validation. This study did not explicitly mention the number of PV panels or datasets used for the characterization and optimization process, which could raise concerns about the representativeness of the results. The absence of rigorous validation against uncertainty could raise concerns about the accuracy and reliability of the optimized model parameters. A fast method was introduced by A. Laudani et al. in 2014 to efficiently determine the five parameters of the one-diode model using the experimental I-V curve of a photovoltaic (PV) panel [
23]. The method utilized reduced forms of the original five-parameter model, dividing the parameters into independent and dependent unknowns. This division helped reduce the search space dimensions, resulting in significant advantages in terms of convergence, computational costs, and execution times. However, this study derived several simplifications, and so the optimality of the obtained parameters are questionable, whereas only a single diode model was utilized. In 2015, an approach was presented by L. Lim et al. to solve a set of nonlinear equations using a limited number of points on an I-V curve [
24]. The study established a connection between the diode model parameters and the transfer function of the dynamic system after applying the Laplace transform. Notably, this study focused solely on a single-diode model, limiting the scope of its analysis.
Furthermore, the genetic algorithm (GA) has been proposed to extract solar PV systems’ parameters [
13,
25]. In [
25], the aim of the study was to enhance the design variables of the solar PV cell in the context of SDPVM. In [
13], the authors improved the efficacy of the traditional GA by integrating novel mutation approaches and crossover methods. The utilization of non-uniform mutation and mixed crossover is employed in this context. The improved GA’s performance is evaluated according to a comparison with the experimental data. The newly implemented GA produces estimated curves that exhibit a lower number of errors compared to the experimental curves.
The grasshopper algorithm (GOA) has been suggested to define optimal factors for solar PV systems [
6,
20]. In [
20], the suggested GOA was applied to extract the TDPVM parameters with consideration of the solar irradiation and cell temperature variations. Indeed, it was implemented to find the parameters of both SDPVM and DDPVM [
20]. Additionally, the authors suggested the manta ray foraging optimization (MRFO) technique to handle the PV parameter extraction computational problem [
26]. The MRFO method has been tested to determine the parameters of SDPVM, DDPVM, and TDPVM. Both solar irradiance and temperature changes have been considered in the problem’s formulation.
Several optimization algorithms have also been proposed to solve the problem of parameter extraction in a solar PV system. These include the supply and demand optimizer [
27], the Harris hawk optimization [
17], the arithmetic optimization approach [
28], the improved estimation of distribution algorithm [
29], the heap-based optimizer [
30], artificial parameterless optimization [
31], the black widow optimization algorithm [
32], hunter–prey-based optimization [
33], the improved generalized normal distribution algorithm [
5], the biogeography-based teaching learning algorithm [
34], hybrid variants of artificial gorilla troops and honey badger algorithm techniques [
35], a hybrid adaptive Jaya algorithm [
1], and particle swarm optimization [
36].
The use of metaheuristic algorithms for parameter estimation in PV systems has been widely adopted.
Table 1 tabulates the merits and demerits of some of the literature optimization techniques. However, it is important to note that no single algorithm can solve all optimization problems, as stated in Wolpert and Macready’s “No Free Lunch” theorem [
37]. Over the past 30 years, researchers have made significant advancements in metaheuristic algorithms and have introduced new ones. Despite these improvements, many studies aiming to enhance the performance of these algorithms have highlighted their limitations in accurately and reliably estimating parameters for various photovoltaic models. Therefore, there is a need to develop new approaches that result in simple and efficient metaheuristic algorithms capable of solving practical optimization problems without the need for additional parameter adjustments and modifications.
J. O. Agushaka et al. [
41,
42] introduced the Dwarf Mongoose Optimizer (DMO), a revolutionary approach inspired by the foraging behavior of the dwarf mongoose animals (DMAs), in 2022. The foraging behavior of the DMAs motivated the DMO’s primary design. It makes use of distinct DMA societal groups including the alpha category, scouts, and babysitters. The alpha female initiates foraging and chooses the foraging path, bedding places, and distance travelled for the group. A combination of its strong global exploring capacity and robustness motivates the implementation of the DMO for handling a variety of genuine engineering optimization difficulties [
43,
44,
45,
46,
47,
48,
49,
50]. A modified intelligent metaheuristic version of the DMO (MDMO) is proposed in this article for the optimal modelling and parameter extraction of solar photovoltaic (SPV) systems. The newly introduced MDMO features an additional alpha-directed knowledge-gaining strategy to boost seeking expertise, and its modifying technique has been partially guided by the modified alpha.
The newly presented MDMO has an extra alpha-directed knowledge-gaining strategy to increase searching expertise, and its modifying approach has been led to some extent by the amended alpha. For diverse SPV modules, such as the Kyocera KC200GT and R.T.C. France SPV modules, the proposed MDMO is used as opposed to the DMO to efficiently estimate SPV characteristics. The simulation findings enhance the electrical properties of SPV systems by using the MDMO technique. In terms of efficiency and efficacy, the proposed MDMO outperforms the standard DMO. Two primary contributions of this paper can be summarized as follows:
A novel MDMO is presented with an extra alpha-directed knowledge-gaining strategy to increase searching expertise.
The proposed MDMO is designed to acquire the best SPV features by taking into account three distinct modelling types: SDPVM, DDPVM, and TDPVM.
Based on the simulation results, the proposed MDMO is employed in SPV technologies, including Kyocera KC200GT and R.T.C. France SPV modules. Furthermore, the proposed MDMO is statistically evaluated in comparison to previously reported optimization processes in the literature.
2. SPV Systems Representation
Numerous mathematical models are available that analyze the functioning and physical characteristics of solar PV systems. This section provides an overview of the mathematical representations of the solar PV cell that can be modeled by SDPVM, DDPVM, and TDPVM.
2.1. SDPVM
Figure 1 depicts the equivalent circuit representation of the SDPVM. This model consists of single-diode, irradiance sources modeled as current source, series resistance, and shunt resistance. The output current (I) is derived by applying the Shockley diode equation, represented as Equation (1) [
51,
52].
where
Ir1 represents the reverse saturation current of D
1,
γ1 characterizes the ideality coefficient of D
1, and
Rsh and
Rs denote the shunt and series resistances, respectively. Additionally,
IPV and
I express the cell photocurrent and the output current, respectively. Furthermore,
V is the terminal voltage and
Vth represents the PV cell thermal voltage that can be calculated as follows [
53]:
where
kB denotes the Boltzmann’s constant,
qc represents the electron’s charge and
T stands for the absolute temperature.
In this model, there are five unknown parameters (IPV, Ir1, Rs, Rsh, γ1) that must be calculated from the solar PV cells’ I-V data.
2.2. DDPVM
Figure 2 illustrates the equivalent circuit representation of the DDPVM. This model is considered as an improved version of SDPVM. An extra diode is added in this version to demonstrate a space charge recombination. The output current equation of the DDPVM is mathematically calculated as in Equation (3) [
33,
54].
where
Ir2 represents the reverse saturation current of D
2 and
γ2 characterizes the ideality coefficient of D
2.
There are seven unknown parameters in this model that must be calculated from the solar PV cells’ I-V data, which are IPV, Ir1, Ir2, Rs, Rsh, γ1, and γ2.
2.3. TDPVM
In TDPVM, the third diode is added to improve the DDPVM, as displayed in
Figure 3. The third diode is added to represent recombination in the defect area. The output current equation of the TDPVM is mathematically calculated as Equation (4) [
55,
56].
In this model, there are nine unknown parameters (IPV, Ir1, Ir2, Ir3, Rs, Rsh, γ1, γ2, γ3) that must be calculated from the solar PV cells’ I-V data.
2.4. Representations of SPV Modules
The equations of the SDPVM, DDPVM, and TDPVM may be represented by a PV module composed of
N1 cells linked in parallel and
N2 cells connected in series. As a result, for these models, Equations (5)–(7) are formulated, respectively, as follows:
PV cells/modules for SDPVM, DDPVM, and TDPVM have unidentified variables that can be estimated computationally, analytically, or using optimization approaches.
2.5. Objective Function
The statistical evaluation performed in this paper relied on the root mean square error value (
RMSE) [
57] and is carried out as follows:
where
Nc represents the number of measured readings;
IExp,c and
VExp,c are the measured readings of each record regarding, respectively, the current and voltage; and
ICalculated,c is the calculated output current, which is a nonlinear function in terms of the experimental voltage (
VExp,c) readings of each record and the unknown parameters (x).
3. Proposed MDMO for Optimal Modeling of SPV Systems and Parameter Extraction
The dwarf mongoose optimizer (DMO) is created by studying the foraging behavior of dwarf mongoose animals (DMAs). In the presented meta-heuristic technique (DMO), the population of DMAs is initially generated as follows [
56,
58]:
where
m is an integer as a counter, which is equal to 1, 2, 3, 4, 5,………,
NDMA;
NDMA is the entire population of the dwarf mongoose animals. In Equation (9), the symbol “.” represents the dot product, which is a fundamental way of combining two vectors, indicating the product of each element in the vector and the respective one in the other vector with same dimension.
Xm specifies the position of each DMA (
m), and
Xmin and
Xmax signify the lowest and maximum bounds.
R is a randomized vector of dimension (
D) in relation to the entire number of control variables and
NDMA signifies the total size of DMAs group.
Next, in the initialization of the DMAs’ positions, the fitness rating (
FSm) of every solution (
Xm) is evaluated. Following that, the alpha female is chosen depending on the probable value (α
m) of every group’s fitness as follows:
where α
m is the probability value of each animal in the group.
In the alpha organization, the number of DMAs is proportional to the population size minus the number of babysitters (
Bs). The symbol (
peep) observes the alpha’s vocalization, which keeps the DMAs on track. Each DMA rests within the first sleeping area which has been assigned to them. To generate the next position towards the projected food position, the DMO employs the equation described in Equation (11).
where
Bs is the number of babysitters in the entire group and
T represents the present iteration.
The young dwarf mongooses are moved from one sitting mound to a different one rather than having a home built for them. In addition to searching for food, the alpha group scouts for an alternative mound to attend after the babysitting exchange requirement is satisfied. In order to replicate this, the average value of the sitting mound is estimated for each iteration, which may be represented in the following manner:
where
FSm(
T) is the fitness score of the current solution (
Xm) at the current iteration (
T) and
FSm(
T + 1) is the fitness score of the updated solution (
Xm) at the consequent iteration (
T + 1).
The mean value (
ψ) of the observed sitting mound is given as follows:
Based on the overall success of the DMAs, the progression that follows is represented as a success or failure assessment while creating a new mound [
59]. The following equation can be used to model the scout mongoose:
where
CF reduces gradually as its iterations progress, which is demonstrated in Equation (15), and
M appears to be a vector which impacts the DMAs’ eventual sleeping area migration and is calculated in Equation (16). The CF factor represents the value of the parameter which controls the DMA organization’s collective–volitive motion.
where
Tmax represents the total number of iterations.
In order to increase the searching expertise, the alpha-directed knowledge-acquiring technique is paired with the formula described in Equation (11) to construct a likely food location with the goal of increasing the seeking skills:
where
Xm(
T + 1) indicates the updated solution (
Xm) at the consequent iteration (
T + 1).
XAlpha(T) corresponds to the alpha location having the smallest objective worth;
R is a randomized vector of dimension (
D);
Xm(
T) indicates the current solution (
Xm) at the current iteration (
T);
XRd refers to the position of a randomly selected DMA;
r1 represents a randomly generated number within range [0, 1]; and
PSF indicates the probability of the selection factor.
Figure 4 depicts the critical steps of the projected MDMO.