Variable Step Perturbation Research Articles

Combining dynamic adaptive snake algorithm with perturbation and observation for MPPT in PV systems under shading conditions

Photovoltaic (PV) systems play an increasingly vital role in the global new energy landscape. However, when PV arrays are affected by partial shading, their power-voltage (P-U) characteristic curves exhibit dynamic multi-peak features, posing challenges to traditional Maximum Power Point Tracking (MPPT) techniques, including slow convergence speed, low tracking efficiency, and oscillations around the Maximum Power Point (MPP), leading to unnecessary power losses. Therefore, this study proposes a dual-layer control MPPT technology that integrates dynamic adaptive snake optimization algorithm with variable step perturbation and observation (ISO-IP&O) to address the MPP extraction problem of PV systems under complex weather conditions. This study compares and analyzes the proposed ISO-IP&O controller with current renowned MPPT techniques, including Grey Wolf Optimization combined with P&O (GWO-P&O), Improved Squirrel Search Algorithm (ISSA), Original Snake Optimization (SO), Horse Herd Optimization (HHO), and Adaptive Factor Selection Multi-Swarm Particle Swarm Optimization (FMSPSO), validating the effectiveness of the proposed ISO-IP&O controller. Simulation results demonstrate that the ISO-IP&O technology achieves an average tracking efficiency of 99.91 % under various shading conditions, with an average convergence speed of only 0.07 seconds. Compared with other existing methods, the ISO-IP&O technology exhibits superior performance in terms of GMPP tracking speed, maximum power tracking efficiency, and stability. Experimental validation on the HIL+RCP physical experimental platform shows that under eight partial shading conditions(PSC), the proposed method still achieves the highest average tracking efficiency of 99.68 %, with the fastest average tracking speed of 0.66 seconds. The ISO-IP&O controller achieves rapid, robust, and efficient GMPP tracking under various complex shading conditions, contributing to the enhancement of PV system performance.

Interoperability Improvement for Rectangular Pad and DD Pad of Wireless Electric Vehicle Charging System Based on Adaptive Position Adjustment

Wireless charging for electric vehicles has been investigated in recent years. One of the critical issues of the research is to improve the weak interoperability between two popular charging pads—rectangular pad (RCP) and double-D pad (DDP). This article intends to model the interoperability under pad misalignment and improve it by adjusting the pads’ relative position. First, the variation of interoperability with pad misalignment is analyzed by the flux model. Full output power and high transmission efficiency can be achieved when the two pads are misaligned to a certain distance. Second, the optimal misalignment is obtained by flux calculation and simulation. Third, an adaptive position adjustment method for the transmitting pad based on the variable-step perturbation and observation algorithm is proposed. By searching the maximum dc input current, the optimal position of the transmitting pad can be found. Finally, in the experiment, a 3.3 kW output with 95% coil-coil efficiency is realized when the RCP and DDP interoperate at the optimal position. Compared with the scenario without position adjustment, the improvement of output power and efficiency proves that the proposal can optimize the interoperability between the RCP and DDP.

Research on control strategy of maximum power tracking variable step size perturbation & observation method for photovoltaic power generation system

There are three defects of traditional perturbation and observation method in the maximum power tracking control process of photovoltaic power generation systems, which are oscillation, misjudgment and poor tracking accuracy. Thus, a variable step perturbation and observation method based on power prediction is proposed for three-level DC/DC converters in this paper, which effectively solved oscillation, misjudgment, tracking accuracy problems, improving the tracking speed and precision of the algorithm, and the verification results of the maximum power tracking algorithm based on the three-level DC/DC converter structure has also been indicated.

Constant Current Charging and Maximum System Efficiency Tracking for Wireless Charging Systems Employing Dual-Side Control

Wireless power transfer (WPT) systems have attracted much attention because of their safety, convenience, and environmental friendliness. For wireless supercapacitor charging, the system efficiency and charging current are highly dependent on the load that varies over a wide range. In this article, a simultaneous maximum system efficiency (MSE) tracking and constant current (CC) charging control scheme for a supercapacitor is proposed. For CC charging, a double-sided LCC topology is chosen due to its characteristic of providing a load-independent output current. Furthermore, the impact of the coil internal resistance on the system characteristics (especially the charging current) is investigated, so a semiactive rectifier is introduced on the secondary side to achieve accurate CC charging and improve the system robustness. Based on the variable-step perturbation and observation algorithm, the MSE is tracked by searching for the minimum system input dc current using a primary-side buck converter on the premise that the charging current reaches its target value. The abovementioned two control loops are independent, and mutual communication is unnecessary when they cooperate; thus, the system is simplified. The simulation and experimental results show great consistency with the theoretical analysis. The experimental system maintains the MSE of 86% during charging the supercapacitor from 20 to 50 V with 2 A.

Implementation in Arduino of MPPT Using Variable Step Size P&O Algorithm in PV Installations

In order to maximize the electric energy production of a photovoltaic generator (PVG), the maximum power point tracking (MPPT) methods are usually used in photovoltaic systems. The principle of these techniques is to operate the PVG to the maximum power point (MPP), which depends on the environmental factors, such as solar irradiance and ambient temperature, ensuring the optimal power transfer between PVG and load. In this paper, we present the implementation of two digital MPPT commands using the Arduino Mega type. The two proposed MPPT controls are based on the algorithm of perturb and observe (P&O), the first one with fixed perturbation step and the second one with two perturbations step varying with some conditions. The experimental results show that the P&O algorithm with variable step perturbation gives good results compared to the P&O algorithm with fixed perturbation step in terms of the time response and the oscillations around the MPP.

Research on MPPT Algorithm Based on Mixed Strategy

Based on the mathematical model of PV array and its output characteristics, a hybrid control strategy combining fixed step method and variable coefficient approximation method is proposed. The method is followed by a fixed step in the search of the maximum power point. When the slope of the PU curve changes for the first time, the search interval is fixed in an initial step, and then the search is gradually approximated to maximum power point in the section. The method is analyzed theoretically and modeled in Matlab / Simulink environment, and compared with the variable step perturbation observation method. The simulation results show that the proposed method can quickly and accurately track the maximum power point under the standard condition and the sudden change of light intensity, and has faster tracking speed.

Photovoltaic Array Maximum Power Point Tracking Based on Improved Method

At present, a good deal of methods for the Maximum Power Point Tracking (MPPT) has been used in engineering applications. However, Matlab simulation proved that they were difficult to harmonize the stability and speed ability of system. In addition, in order to maximize the use of PV panels ‘power, the paper focused on aneonatalalgorithm for Maximum Power Point Tracking (MPPT). Based on the algorithm, this paper designed an improved and feasible variable step perturbation and observation method which well alleviated the conflict that the maximum power point tracking could not take into account the stability and speed of response efficiently.

Research on Modeling and Control Strategy for Two-Stage Photovoltaic Grid-Connected System

This paper has built the mathematic model of the single-phase two-stage photovoltaic(PV) grid-connected system. The model consists of a boost DC/DC converter and a DC/AC inverter with LCL filter. On the basis of the variable step perturbation and observation method(P&O), the boost converter changes the output voltage of the PV array by adjusting the duty cycle to realize the PV maximum power point tracking(MPPT). The inverter system restrains the voltage fluctuation effectively by using feed-forward of the grid voltage and current tracking control technology, which has the high performance in both sinusoidal reference tracking and disturbance rejection. LCL filter improves the dynamic performance and restrains the high harmonics efficiently. The simulation with Matlab soft confirms the effectiveness of the model and control strategy.

Simulation of Tracking Control Modeling of the Photovoltaic System with Maximum Power

This paper mainly studies the off grid wind solar hybrid power supply system based on the DC bus, a practical mathematical model, implemented in MATLAB software on the system modeling and simulation. Through controlling the light intensity, temperature and other environmental parameters, operating characteristics of the system, analysis of system output voltage (current), dynamic and steady-state output power parameters. On the basis of the maximum power point tracking (MPPT) problem, and the maximum power point of PV power generation system tracking (MPPT) in-depth simulation experiments, using variable step perturbation and observation method, and the corresponding simulation model is established in MATLAB, changes in the environment variable parameters of the system can make timely adjustment re operation, in the vicinity of the maximum power point, and the work efficiency and the operating characteristics of the system through the analysis of the problem.

Variable Step Perturbation MPPT Method Based on Fuzzy Control for Wind Power Generation System

Traditional MPPT control strategy by hill climbing searching for wind power generation system (WPGS) dependent on wind turbines parameters, the oscillation around maximum power point (MPP) was serious. A new variable step perturbation MPPT was presented based on fuzzy control, the variable perturb step was determined with the power characteristic curves point slope, the control system was described with fuzzy language for maximum power capture, the principle of MPPT was analyzed and the variable step method was adopted with fuzzy control, the simulation result shows that this advanced control strategy could improve tracking speed, enhance the stability and the oscillation around maximum power point reduced.

Researched on Maximum Power Point Tracking of PV Power System

To the oscillation and misjudgment problem of the traditional perturbation and observation algorithm, a novel three-point comparison method was proposed. This method applied Constant Voltage Tracking (CVT) method and variable-step perturbation method to solve the problem between tracking accuracy and speed, and applied double-direction perturbation method to make sure the reliability of action to avoid the misjudgment when external conditions fast changing. Restraining the oscillation near the maximum power point effectively was another merit of this proposed method. Finally, the experimental results demonstrate effectiveness of proposed method with PV experimental platform.