•Numerical computation of intricate PV equation complicates the structure of Photovoltaic emulator.•A new emulator based on a straightforward explicit PV model is introduced.•Integration of the ...explicit model into the PV features high simplicity and accuracy.•Developed PVE requires just one iteration to compute the PV model.•Proposed emulator is suitable for field PV testing.
This paper presents a novel simplified and flexible Photovoltaic emulator (PVE) that effectively emulates the static and dynamic characteristics of a solar panel. By meticulously generating a benchmark for the entire system, the proposed PVE utilizes an original explicit PV model (EPVM). As an approximation of the implicit equation of the PV, the EPVM employs a Taylor series resolution. This methodology eliminates the necessity for numerous iterative computations, in contrast to previous frameworks, and as a result possesses formidable computational capabilities. Furthermore, it is clearly illustrated that the EPVM can be effortlessly incorporated into the PVE architecture, resulting in a straightforward and simplified procedure that contributes to its overall flexibility and simplicity. Using MATLAB/Simulink and a 200 W solar system, the developed PVE is investigated numerically. Through the application of nonlinear processes such as (maximum power point tracking) MPPT, the PVE's viability is confirmed. This study repeatedly emphasizes the superior qualities of the proposed PVE in simulating a solar panel in a straightforward, precise, and efficient manner, by conducting a comparative analysis with contemporary PVE designs. It is consistently determined through quantitative evaluations that the developed PVE achieves an efficiency exceeding 99 % and a maximum error rate of less than 0.7 %.
This paper proposes a new no-equilibrium chaotic system that has the ability to yield infinitely many coexisting hidden attractors. Dynamic behaviors of the system with respect to the parameters and ...initial conditions are numerically studied. It shows that the system has chaotic, quasiperiodic, and periodic motions for different parameters and coexists with a large number of hidden attractors for different initial conditions. The circuit and microcontroller implementations of the system are given for illustrating its physical meaning. Also, the synchronization conditions of the system are established based on the adaptive control method.
This paper presents a new image encryption algorithm based on 3D chaotic system and deoxyribonucleic acid (DNA) coding. It uses two keys, an external one of 128 bits long and an internal one of ...64 gray values coming from the plain image. The initial conditions come from the two keys and vary from one line of the image to the other and from one image to the other and consequently the sequences of substitutions too. In general, in image encryption based on 3D chaotic systems, each chaotic variable is used independently of the others in one phase of the encryption. Here we use the zigzag process to combine the sequences from all the variables before using them simultaneously in the encryption process. DNA coding generally uses one of the 24 DNA rules and one of the 16 join operations to perform the encryption. Here we use all the 24 rules dynamically as well as the 16 join operations in the encryption. Also we apply the chaotic permutation on DNA chain. The logical DNA operations are used according to an algorithm similar to that of the Fast Walsh Transform (FWT) in those 24 DNA rules. The algorithm has been evaluated. It has good statistical properties of cipher images. The proposed system presents high sensitivity on the encryption-decryption keys and on the plain images. These latter features make the proposed algorithm very efficient, robust and resistant against brute force attacks and good for the future secure image communication.
In this paper, we present a study of a simplified optoelectronic oscillator (OEO) that features both the laser and the filter nonlinearities. We show that this optoelectronic oscillator depicts the ...phenomena of quasi-sinusoidal oscillations when the feedback gain is small, relaxation and chaos oscillations when the feedback gain increases. It is analytically confirmed that the frequencies of the limit-cycle oscillations increase with the cubic-nonlinear term and the feedback gain but decrease with the time-delay of the system. The experimental measurements are qualitatively in agreement with the theoretical and numerical analysis.
Electronic power converters are in a state of exhibiting some complex features which can be influenced by the converter’s structure parameters and load, as well as its pulse period. In this paper, we ...propose to investigate these phenomena occurring in the dc/dc buck converter by carrying out the dynamics of the said system when it exhibits the fingerprints of frequency-dependent pinched hysteresis loops. The essential part of this study is consecrated to the nonlinear dynamics when the converter load is memristive. Under two kinds of switch states, the independent nonlinear models and equations are derived which provide a complete dynamics description of the system under investigation. The dynamics analysis is performed by making use of bifurcation tools, phase portraits, and two parameters Lyapunov diagrams showing that the system depicts very rich and striking behaviors such as periodic orbits, period-doubling bifurcation, quasiperiodicity, chaos, and pinched hysteresis loops of the memristive load. Finally, the numerical simulation results are in almost perfect agreement with the analog result obtained with PSIM. The results obtained in this work have not yet been reported in the literature to the best of our knowledge and thus deserve dissemination.
We investigate the dynamics of a simple jerk circuit where the symmetry is broken by forcing a dc voltage. The analysis shows that with a zero forcing dc voltage, the system displays a perfect ...symmetry and develops rich dynamics including period doubling, merging crisis, hysteresis, and coexisting multiple (up to six) symmetric attractors. In the presence of a non-zero forcing dc voltage, several unusual and striking nonlinear phenomena occur such as coexisting bifurcation branches, hysteresis, asymmetric double scroll strange attractors, and multiple coexisting asymmetric attractors for some appropriate sets of system parameters. In the latter case, different combinations of attractors are depicted consisting for instance of two, three, four, or five disconnected periodic and chaotic attractors depending solely on the choice of initial conditions. The investigations are carried out by using standard nonlinear analysis tools such as Lyapunov exponent plots, bifurcation diagrams, basins of attraction, and phase space trajectory plots. The theoretical results are checked experimentally and a very good agreement is found between theory and experiment.
This work deals with the dynamical analysis and FPGA implementation of a pendulum controlled by a delayed proportional feedback force. The system has infinity equilibrium points and so the nature of ...these points is established according to the value of the gain of the controller. Analysis of the effect of delay on the linear system through a stability chart revealed stability switching. The Hopf bifurcation curves are presented gradually as the delay varies and thus confirm the analytical predictions. Furthermore, these bifurcation diagrams show the existence of complex behaviours and the coexistence of infinity strange attractors for different initial values. This system can be considered as a self-producer of attractors depending on the initial conditions. For certain values of the delay, the system exhibits the multiscroll behaviour which can be observed through the phase portraits. The FPGA implementation of the system is based on the VHDL hardware description which takes into account the RK4 resolution method with calculations under the 32-bit 16Q16 fixed-point number standard.
The dynamic natural processes which occur in the world terrestrial system are highly nonlinear and exhibit unpredictable oscillations and behaviors. One way to imitate and follow the essential ...characteristics of these processes is a similar study of the nonlinear dynamics of two subsystems whose evolution is fast and slow, respectively. These dynamic systems are commonly used to describe various aspects of the dynamics of natural disasters in order to predict a solution. This article examines the dynamic properties and phenomena of a slow–fast 4D system consisting of the Duffing equation coupled to a proposed memristive system. The dynamics of the obtained system reveals the presence of multistability which is an unpredictable phenomenon whose different coexisting states must be quantified in order to adopt a means of control for better forecasting of disasters. Furthermore, the effect and strength of the coupling parameter on the interaction between the slow–fast dynamics of the subsystems is observed. Other dynamic properties such as offset boosting and bursting oscillations are also observed, further justifying the complexity of the system. An analog validation of the mathematical model is proposed through PSpice simulations of the corresponding electronic circuit, and the results sufficiently justify the feasibility.
Regions of stability phases discovered in a general class of Genesio−Tesi chaotic oscillators are proposed. In a relatively large region of two-parameter space, the system has coexisting point ...attractors and limit cycles. The variation of two parameters is used to characterize the multistability by plotting the isospike diagrams for two nonsymmetric initial conditions. The parameters window in which the jerk system exhibits the unusual and striking feature of multiple attractors (e.g., coexistence of six disconnected periodic chaotic attractors and three-point attraction) is investigated. The second aspect of this study presents the synchronization of systems that act as mediators between two dynamical units that, in turn, show function projective synchronization (FPS) with each other. These are the so-called relay systems. In a wide range of operating parameters; this setup leads to synchronization between the outer circuits, while the relaying element remains unsynchronized. The results show that the coupled systems can achieve function projective synchronization in a determined time despite the unpredictability of the scaling function. In the coupling path, the outer dynamical systems show finite-time synchronization of their outputs, that is, displaying the same dynamics at exactly the same moment. Further, this effect is rather general and it has a wide range of applications where sustained oscillations should be retained for proper functioning of the systems.
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