Improved Maximum Power Point Tracking Research Articles

A Modified Perturb-and-Observe Control for Improved Maximum Power Point Tracking Performance on Grid-Connected Photovoltaic System

A Modified Perturb-and-Observe Control for Improved Maximum Power Point Tracking Performance on Grid-Connected Photovoltaic System

Improved Maximum Power Point Tracking Algorithm for Photovoltaic Systems

Research was carried out into existing methods of maximum power point tracking (MPPT) for photovoltaic systems. This paper compares existing approaches to maximum power point tracking and presents a new learning-based technique which exceeds the performance of existing methods. Simulation and experimental results are presented which indicate that the new algorithm offers benefits over other methods described.

Grid-Connected PV System for 324 kW with Improved Maximum PowerPoint Tracking

The purpose of this work is to analyze and studded, a grid-connected with a double-stage converter DC/DC, a three-phase five-level inverter system, battery energy system (BESS) with dynamic and static loud. A DC/DC modified boost converter is used to get to most power out of the photovoltaic array along with increasing output voltage. The duty cycle is changed in an incremental conductance maximum power point tracking (MPPT) technique to reach the maximum power point (MMP). In a rotating d-q synchronous reference frame, the multilevel voltage source inverter converts the maximum voltage (VSI). power obtained from first stage power converter (DC-DC) to AC power utilizing a droop controller approach. Finally, the simulation results demonstrated the effectiveness of the proposed modified MPPT strategy for tracking the maximum power under shading conditions with an accuracy of up to 98.5%. The suggested AC controller results also show robust performance for synchronizing with the utility grid with a minimum THD of up to 2.4%.

A new approach for improving the efficiency of the indirectly coupled photovoltaic-electrolyzer system

Hydrogen as an energy storage medium is considered an effective solution to the problem of the intermittent availability of renewable and innovative energies. This study focused on improving the efficiency of an indirectly coupled photovoltaic-electrolyzer (PVE) system using an improved maximum power point tracking (IMPPT) technique. The IMPPT is based on a neural current estimator and a variable step size (VSS) technique. The neural network-based current estimator is employed to estimate the short circuit current (Isc) quickly and directly without the need for periodic disconnection of the PV system, which in turn, reduces the losses resulting from the measurement process. The VSS technique is used to achieve an optimal adjustment of the duty cycle. The accurate electrical model of the PVE system was simulated in MATLAB/Simulink environment. The system performance was evaluated for one day using actual radiation data of Zonguldak City on June 19, 2021. Simulation results show that using the proposed IMPPT system, the PVE system achieves higher performance compared to using both P&O-based MPPT and directly coupled mode. Assuming an ideal electrolyzer, the efficiencies of the PVE system were about 91% using the IMPPT, 67% using the P&O-based MPPT, and 45% using the directly coupled mode. This demonstrates that the proposed system exhibits superior performance and increases hydrogen production efficiency compared to directly coupled PVE systems that need fine-tuning of system parameters.

Single-Stage Grid-Connected PV System With Finite Control Set Model Predictive Control and an Improved Maximum Power Point Tracking

The single-stage grid-connected photovoltaic (PV) topology has recently drawn attention as it can reduce overall losses and installation costs. This paper presents a new control approach for single-stage grid-connected PV systems. The proposed controller is a combination of a finite control set model predictive control (FCS-MPC) and a maximum power point tracking (MPPT) algorithm, which ensures the extraction of maximum power from the PV panels and good transient performance for the output voltage and current. The disadvantages of classical MPPT algorithms in tracking the global maximum power point under fluctuating environmental conditions are avoided by including additional constraints in the cost function of the FCS-MPC. Further, the controller is tested for partial shading in PV. The performance of the proposed controller is compared with the two-stage and single-stage PV configuration with different controls and MPPT algorithms. The simulation results show that the single-stage PV system with the proposed control can effectively extract the maximum power from the PV system and maintain a stable output signal for the transient condition. Finally, experimental results according to a control hardware-in-the-loop (C-HIL) approach are presented to validate the effectiveness of the proposed algorithm.

Modeling and Test Results of an Innovative Gyroscope Wave Energy Converter

An improved Maximum Power Point Tracking (MPPT) method based on a purely mechanical wave energy converter (WEC) of gyroscope precession is proposed. The method adopts dynamic perturbation step adjustment, which improves the stability of power output and reduces steady-state oscillation. The paper introduces the principle of the device, establishes the mathematical model, and obtains the complete expression of power. The effect of wave frequency, pitch amplitude, power take-off (PTO) damping coefficient, and flywheel rotating speed on power output is analyzed. The output regression equation is established, and the extraction conditions of the maximum power are summarized and predicted. Aiming at the time-varying nature of actual ocean waves, a variable step size modified maximum power point (MPP) tracking control algorithm based on perturbation and observation (P&O) method is proposed. The algorithm has a unique technology to dynamically change the perturbation size, which not only improves the dynamic response but also reduces the oscillation. Besides, the boundary conditions ensure that the algorithm will not deviate from the motion trajectory, and the average filtering method and steady-state judgment can further reduce steady-state oscillation. In various ocean conditions, the proposed method has better output stability compared with other variable step size algorithms. Finally, different wave working conditions are given in the experiment, and the results verify the effectiveness of the proposed MPPT control strategy in experimental equipment. The device will be suitable for distributed power sources in small islands and ports.

A new robust control scheme: Application for MPP tracking of a PMSG-based variable-speed wind turbine

This paper proposes a novel Improved Maximum Power Point Tracking (IMPPT) algorithm to extract the maximum available power from a direct-drive Permanent-Magnet Synchronous Generator (PMSG) based standalone Small-scale Variable Speed Wind Turbine (VSWT). The proposed control scheme consists of an IMPPT algorithm to effectively improve the extracted power under various regimes of wind speed. The IMPPT constructs the reference value of the DC voltage for the DC bus. Moreover, a composite low-cost controller (LCC) is also proposed in order to improve the DC voltage tracking based on a new designed nonlinear state observer. The proposed nonlinear robust controller accounts for the overall system dynamics and nonlinear behavior. The objective is to improve the dynamic performance and ensure a good balance of energy conversion efficiency, robustness, cost efficiency, and a simple structure for practical implementation in wind energy conversion systems. Furthermore, the stability of the closed-loop system is analyzed and guaranteed through Lyapunov stability theory. Moreover, two scenarios are used for validation in Matlab/Simulink, including step change and stochastic profiles of wind speed. Simulation results verify the effectiveness and superiority of the IMPPT-LCC approach whereas comparisons with other techniques prove its superiority.

MPPT of Permanent Magnet Synchronous Generator in Tidal Energy Systems Using Support Vector Regression

In this paper, an improved Maximum Power Point Tracking (MPPT) algorithm for a tidal power generation system using a Support Vector Regression (SVR) is proposed. To perform this MPPT, a tidal current speed sensor is needed to track the maximum power. The use of these sensors has a lack of reliability, requires maintenance, and has a disadvantage in terms of price. Therefore, there is a need for a sensorless MPPT control algorithm that does not require information on tidal current speed and rotation speed that improves these shortcomings. Sensorless MPPT control methods, such as SVR, enables the maximum power to be output by comparing the relationship between the output power and the rotational speed of the generator. The performance of the SVR is influenced by the selection of its parameters which is optimized during the offline training stage. SVR has a strength and better response than the neural network since it ensures the global minimum and avoids being stuck at local minima. This paper proposes a high-efficiency grid-connected tidal current generation system with a permanent magnet synchronous generator back-to-back converter. The proposed algorithm is verified experimentally and the results confirm the excellent control characteristics of the proposed algorithm.

Control Strategy of Intergrated Photovoltaic-UPQC System for DC-Bus Voltage Stability and Voltage Sags Compensation

Power quality problem, because of its various forms and occurrence frequency, has become one of the most critical challenges confronted by a power system. Meanwhile, the development of renewable energy has led to more demands for an integrated system that combines both merits of sustainable energy generation and power quality improvement. In this context, this paper discusses an integrated photovoltaic-unified power quality conditioner (PV-UPQC) and its control strategy. The system is composed of a series compensator, shunt compensator, dc-bus, and photovoltaic array, which conducts an integration of photovoltaic generation and power quality mitigation. The fuzzy adaptive PI controller and the improved Maximum Power Point Tracking (MPPT) technique are proposed to enhance the stability of dc-bus voltage, which is aimed at the power balance and steady operation of the whole system. Additionally, the coordinate control strategy is studied in order to ensure the normal operation and compensation performance of the system under severe voltage sag condition. In comparison to the existing PV-UPQC system, the proposed control method could improve the performance of dc-bus stability and the compensation ability. The dynamic behavior of the integrated system were verified by simulation in MATLAB and PLECS. Selected results are reported to show that the dc-bus voltage was stable and increased under severe situations, which validates the effectiveness of the proposed integrated PV-UPQC system and its control strategy.

An improved maximum power point tracking method based on decreasing torque gain for large scale wind turbines at low wind sites

With the rapid development of wind power in China, high wind sites have become scarce and are often located far away from major load centers. Due to technological improvement and close proximity to load centers, low wind sites (wind speeds around 3–7m/s) have become economically viable in China. However, the characteristics of low mean wind speed and high turbulence intensity at low wind sites make maximum power point tracking (MPPT) control challenging. Therefore, an improved maximum power point tracking (IMPPT) control approach is proposed in this paper. This approach is based on decreasing torque gain (DTG) control algorithm, and is designed to dynamically adjust the gain coefficient aimed for better energy capture at low wind sites. The proposed IMPPT algorithm is compared with traditional MPPT algorithms by simulation using actual wind speeds, including DTG control, adaptive torque gain (ATG) control, the improved MPPT control based on the reduction of tracking range (RTR-MPPT control), and an improved ATG control based on curve fit method (CF-ATG control). Simulation results verify that the proposed approach (IMPPT algorithm) is more effective.

Application and Comparison Between the Conventional Methods and PSO Method for Maximum Power Point Extraction in Photovoltaic Systems Under Partial Shading Conditions

Several algorithms have been offered to track the Maximum Power Point when we have one maximum power point. Moreover, fuzzy control and neural was utilized to track the Maximum Power Point when we have multi-peaks power points. In this paper, we will propose an improved Maximum Power Point tracking method for the photovoltaic system utilizing a modified PSO algorithm. The main advantage of the method is the decreasing of the steady state oscillation (to practically zero) once the Maximum Power Point is located. moreover, the proposed method has the ability to track the Maximum Power Point for the extreme environmental condition that cause the presence of maximum multi-power points, for example, partial shading condition and large fluctuations of insolation. To evaluate the effectiveness of the proposed method, MATLAB simulations are carried out under very challenging circumstance, namely step changes in irradiance, step changes in load, and partial shading of the Photovoltaic array. Finally, its performance is compared with the perturbation and observation” and fuzzy logic results for the single peak, and the neural-fuzzy control results for the multi-peaks.

New Improved Maximum Power Point Tracking Algorithm for Partially Shaded PV Systems

The paper presents new MPPT algorithm for partial shading of series connected PV cells/modules. In the shaded condition, there is a problem of decrease in the total output power of the PV system. The proposed algorithm aims to reduce this problem by active bypassing of the shaded cells. The algorithm senses the irradiance of each cell and performs calculation in order to decide if to actively bypass the shaded cell or not. Extensive simulation results proved that algorithm works and increases the output power under partial shading conditions. Furthermore, the algorithm becomes more efficient when the number of cells is increased.

Harvesting energy from vibrations of the underlying structure

The use of wireless sensors for structural health monitoring offers several advantages such as small size, easy installation and minimal intervention on existing structures. However the most significant concern about such wireless sensors is the lifetime of the system, which depends heavily on the type of power supply. No matter how energy efficient the operation of a battery operated sensor is, the energy of the battery will be exhausted at some point. In order to achieve a virtually unlimited lifetime, the sensor node should be able to recharge its battery in an easy way. Energy harvesting emerges as a technique that can harvest energy from the surrounding environment. Among all possible energy harvesting solutions, kinetic energy harvesting seems to be the most convenient, especially for sensors placed on structures that experience regular vibrations. Such micro-vibrations can be harmful to the long-term structural health of a building or bridge, but at the same time they can be exploited as a power source to power the wireless sensors that are monitoring this structural health. This paper presents a new energy harvesting method based on a vibration driven electromagnetic harvester. By using an improved Maximum Power Point Tracking technique on the conversion circuit, the proposed method is shown to maximize the conversion coefficient from kinetic energy to applicable electrical energy.

최대 전력점 추종의 속응성을 고려한 무인 태양광 자동차 시스템 설계

This paper proposes an improved Maximum Power Point Tracking method and design methods of unmanned solar vehicle system by parts of hardware, unmanned driving control and power conversion. The hardware design is offered on the weight reduction and structural reliability by using structural analysis software. The technique of curve fitting is applied to unmanned control system due to minimizing the vehicle`s behavior. Furthermore, lateral controller applying actuator dynamics is robust enough to prevent performance degradation by measurement noise regarding position and heading angle. The power conversion system contains battery charger system and tapped-inductor boost converter. In the battery charger system, variable step-size MPPT is conducted for quick response of maximum power point tracking. The validity of the proposed algorithm are verified by simulations and experiments.

An Improved Maximum Power Point Tracking for Photovoltaic Grid-Connected Inverter Based on Voltage-Oriented Control

In this paper, an improved maximum power point (MPP) tracking (MPPT) with better performance based on voltage-oriented control (VOC) is proposed to solve a fast-changing irradiation problem. In VOC, a cascaded control structure with an outer dc link voltage control loop and an inner current control loop is used. The currents are controlled in a synchronous orthogonal <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> , <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i> frame using a decoupled feedback control. The reference current of proportional-integral (PI) <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis controller is extracted from the dc-side voltage regulator by applying the energy-balancing control. Furthermore, in order to achieve a unity power factor, the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i> -axis reference is set to zero. The MPPT controller is applied to the reference of the outer loop control dc voltage photovoltaic (PV). Without PV array power measurement, the proposed MPPT identifies the correct direction of the MPP by processing the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis current reflecting the power grid side and the signal error of the PI outer loop designed to only represent the change in power due to the changing atmospheric conditions. The robust tracking capability under rapidly increasing and decreasing irradiance is verified experimentally with a PV array emulator. Simulations and experimental results demonstrate that the proposed method provides effective, fast, and perfect tracking.