This paper presents a novel modified Levy flight optimization for a photovoltaic PV solar energy system. Conventionally, the Perturb and Observe (P&O) algorithm has been widely deployed in most applications due to its simplicity and ease of implementation. However, P&O suffers from steady-state oscillation and stability, besides its failure in tracking the optimum power under partial shading conditions and fast irradiance changes. Therefore, a modified Levy flight optimization is proposed by incorporating a global search of beta parameters, which can significantly improve the tracking capability in local and global searches compared to the conventional methods. The proposed modified Levy flight optimization is verified with simulations and experiments under uniform, non-uniform, and dynamic conditions. All results prove the advantages of the proposed modified Levy flight optimization in extracting the optimal power with a fast response and high efficiency from the PV arrays.
This paper proposes a novel soft switching isolated dc to dc converter. The proposed topology consists of a basic half-bridge dc-dc converter and an auxiliary circuit. The auxiliary circuit consists of two active switches and one capacitor. The main power switches operate with ZVZCS while the power switches of auxiliary switches operate under ZCS conditions. The output voltage of the proposed converter is varied by PWM control. The main features of the proposed converter are simple circuit, less component count and soft-switching operation over the wide control range. The operating principle, theoretical analysis and design example of the proposed converter are provided. The experimental results obtained from a laboratory scale down prototype are presented and discussed in this paper. The presented results confirm the soft-switching operation of the converter
This paper presents a modified Levy particle swarm optimization (MLPSO) to improve the capability of maximum power point tracking (MPPT) under various partial shading conditions. This method is aimed primarily at resolving the tendency to trap at the local optimum particularly during shading conditions. By applying a Levy search to the particle swarm optimization (PSO), the randomness of the step size is not limited to a specific value, allowing for full exploration throughout the power-voltage (P-V) curve. Therefore, the problem such as immature convergence or being trapped at a local maximum power point can be avoided. The proposed method comes with great advantages in terms of consistent solutions over various environmental changes with a small number of particles. To verify the effectiveness of the proposed idea, the algorithm was tested on a boost converter of a photovoltaic (PV) energy system. Both simulation and experimental results showed that the proposed algorithm has a high efficiency and fast-tracking speed compared to the conventional HC and PSO algorithm under various shading conditions. Based on the results, it was found that the proposed algorithm successfully converges most rapidly to the global maximum power point (GMPP) and that the tracking of GMPP under complex partial shading is guaranteed. Furthermore, the average efficiency for all test conditions was 99% with a tracking speed of 1.5 s to 3.0 s and an average output steady-state oscillation of 0.89%.
28 July 2024 in Journal of Advanced Research in Applied Sciences and Engineering Technology
This paper presents a study of Deterministic Particle Swarm Optimization (DPSO) in maximum power point tracking. DPSO is applied to a standalone PV system with a boost converter. This method is implemented primary to solve the problem in conventional techniques such as Perturb and Observe (P&O) and Incremental Conductance (IC) in failure to detect optimum point under certain condition, fixed step-size and high steady-state oscillation. Deterministic method is applied to conventional Particle Swarm Optimization (PSO) and takes advantage over guiding the behaviour of the particles through experience. The velocity of the particle is predicted and evaluated until the optimum point is achieved. A standalone photovoltaic (PV) system is constructed with MATLAB Simulink and DPSO is deployed and tested by simulation. The effectiveness of DPSO is evaluated under uniform condition at standard test condition (STC), medium and low irradiance. The results show that the DPSO successfully converge at optimum point with low steady-state oscillation, and it has high efficiency.
21 September 2015 in Applied Mechanics and Materials
Switched mode DC-DC converters are electronic circuits which convert a voltage from one level to a higher or lower level voltage. This paper presents a new solution approach to controller and observer controller of DC-DC Buck converter. The designs in this paper of DC-DC Buck converter is input voltage 20V step down to 12V output voltage. For control the system simulation investigation into development of controller and observer controller using MATLAB Simulink® software. The simulation develops of the controller and observer controller with mathematical model of DC-DC Buck converter. This paper also providing LQR controller to compare the performance of the system. Finally, the performance output voltage of DC-DC Buck converter is analyzed in terms of time response, overshoot and steady state error.
Electric vehicles (EVs) are experiencing rapid global adoption driven by environmental concerns and fuel security. This article presents a new dual-source converter based on a hybrid modular multilevel configuration (DCHMMC) designed for optimal cell utilisation in EV battery systems. Contrary to conventional converters that can either charge or discharge the cells using a single source, thereby leaving several cells/modules (Ms) idle during each time step, the proposed converter enables the integration of two sources that can utilise the cells simultaneously. This dual source feature minimises idle cells/Ms, enhances energy efficiency, and supports flexible bidirectional power flow. The proposed converter operates in three distinct modes. The first involves dual-source charging for fast charging and improved vehicle availability. The second involves one source charging while the other discharges for dynamic operation. Finally, the last involves dual-source discharging for maximum power delivery and support vehicle-to-grid (V2G) operation. The simulation results demonstrated smooth multilevel sinusoidal output voltages (Vout_a and Vout_b), each with a peak of 350 V, generated simultaneously using 132 cells (six cells per M, 22 Ms). The total harmonic distortion (THD) values for Vout_a and Vout_b were 0.42% and 2.25%, respectively, confirming the high-quality performance. Furthermore, only 0–36 cells and 0–6 Ms were idle during operation, showing improved cell utilisation.