scholarly journals Improvement of MPPT Control Performance Using Fuzzy Control and VGPI in the PV System for Micro Grid

2019 ◽  
Vol 11 (21) ◽  
pp. 5891 ◽  
Author(s):  
Kim ◽  
Huh ◽  
Ko

This paper proposes the method for maximum power point tracking (MPPT) of the photovoltaic (PV) system. The conventional PI controller controls the system with fixed gains. Conventional PI controllers with fixed gains cannot satisfy both transient and steady-state. Therefore, to overcome the shortcomings of conventional PI controllers, this paper presents the variable gain proportional integral (VGPI) controllers that control the gain value of PI controllers using fuzzy control. Inputs of fuzzy control used in the VGPI controller are the slope from the voltage-power characteristics of the PV module. This paper designs fuzzy control's membership functions and rule bases using the characteristics that the slope decreases in size, as it approaches the maximum power point and increases as it gets farther. In addition, the gain of the PI controller is adjusted to increase in transient-state and decrease in steady-state in order to improve the error in steady-state and the tracking speed of maximum power point of the PV system. The performance of the VGPI controller has experimented in cases where the solar radiation is constant and the solar radiation varies, to compare with the performance of the P&O method, which is traditionally used most often in MPPT, and the performance of the PI controller, which is used most commonly in the industry field. Finally, the results from the experiment are presented and the results are analyzed.

2021 ◽  
Author(s):  
Mohamed Mosaad ◽  
Fahd Banakhr

Abstract Solar photovoltaic (PV) energy has met great attention in the electrical power generation field for its many advantages in both on and off-grid applications. The requirement for higher proficiency from the PV system to reap the energy requires maximum power point tracking techniques (MPPT). This paper presents an adaptive MPPT of a stand-alone PV system using an updated PI controller optimized by harmony search (HS). A lockup table is formed for the temperature and irradiance with the corresponding voltage at MPP (VMPP). This voltage is considered as the updated reference voltage required for MPP at each temperature and irradiance. The difference between this updated reference voltage at MPP and the variable PV voltage due to changing the environmental conditions is used to stimulate PI controller optimized by HS to update the duty cycle (D) of the DC-DC converter. Another lockup table is formed with the temperature, irradiance and the corresponding duty cycle at MPP to convert this MPP technique into an adaptive one. An experimental implementation of the proposed adaptive MPPT is introduced to test the validity of the simulation results obtained at different irradiance and temperature levels.


Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5590
Author(s):  
Chih-Chiang Hua ◽  
Yu-Jun Zhan

This paper proposes a hybrid maximum power point tracking (MPPT) method with zero oscillation in steady-state by combining genetic algorithm (GA) and perturbation and observation (P&O) method. The proposed MPPT can track the global maximum power point (GMPP) fast for a photovoltaic (PV) system even under partial shaded conditions (PSC). The oscillations around the GMPP are eliminated and the power loss can be reduced significantly. In addition, the proposed MPPT can make the PV system operate at the highest efficiencies under various atmospheric conditions. During the MPP tracking, the system will oscillate around the MPPs, resulting in unnecessary power loss. To solve the problem, the artificial intelligence (AI) algorithms, such as PSO, Bee Colony optimization, GA, etc., were developed to deal with this issue. However, the problem with the AI algorithm is that the time for convergence may be too long if the range of the MPP search space is large. In addition, if the atmospheric conditions change fast, the PV system may operate at or close to the local maximum power points (LMPPs) for a long time. In this paper, a method combining the P&O’s fast tracking and GA’s GMPP tracking ability is proposed. The proposed system can stop the oscillations as soon as the GMPP is found, thus minimizing the power loss due to oscillations. The proposed MPPT can achieve superior performance while maintaining the simplicity of implementation. Finally, the simulation and experimental results are presented to demonstrate the feasibility of the proposed system.


Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3539 ◽  
Author(s):  
Marwen Bjaoui ◽  
Brahim Khiari ◽  
Ridha Benadli ◽  
Mouad Memni ◽  
Anis Sellami

This study presents a design and an implementation of a robust Maximum Power Point Tracking (MPPT) for a stand-alone photovoltaic (PV) system with battery storage. A new control scheme is applied for the boost converter based on the combination of the adaptive perturb and observe fuzzy logic controller (P&O-FLC) MPPT technique and the backstepping sliding mode control (BS-SMC) approach. The MPPT controller design was used to accurately track the PV operating point to its maximum power point (MPP) under changing climatic conditions. The presented MPPT based on the P&O-FLC technique generates the reference PV voltage and then a cascade control loop type, based on the BS-SMC approach is used. The aims of this approach are applied to regulate the inductor current and then the PV voltage to its reference values. In order to reduce system costs and complexity, a high gain observer (HGO) was designed, based on the model of the PV system, to estimate online the real value of the boost converter’s inductor current. The performance and the robustness of the BS-SMC approach are evaluated using a comparative simulation with a conventional proportional integral (PI) controller implemented in the MATLAB/Simulink environment. The obtained results demonstrate that the proposed approach not only provides a near-perfect tracking performance (dynamic response, overshoot, steady-state error), but also offers greater robustness and stability than the conventional PI controller. Experimental results fitted with dSPACE software reveal that the PV module could reach the MPP and achieve the performance and robustness of the designed BS-SMC MPPT controller.


2021 ◽  
Vol 13 (2) ◽  
pp. 830
Author(s):  
Haidar Islam ◽  
Saad Mekhilef ◽  
Noraisyah Mohamed Shah ◽  
Tey Kok Soon ◽  
Addy Wahyudie ◽  
...  

When a photovoltaic (PV) system is exposed to physical objects and cloud coverage and connected to bypass diodes, a partial shading condition (PSC) occurs, which causes a global maximum power point (GMPP) and numerous local maximum power points (LMPPs) on the power-voltage (P-V) curve. Unlike conventional MPPT techniques that search for multiple LMPPs on the P-V curve, it is possible to track GMPP straightaway by designing a simple but robust MPPT technique that results in faster tracking speed and low power oscillations. Hence, in this study, an improved proportional-integral (PI) coordinated Maximum Power Point Tracking (MPPT) algorithm is designed to enhance the conversion efficiency of a PV system under PSC with fast-tracking speed and reduced power oscillations. Here, PI controllers are used to mitigating the steady-state errors of output voltage and current of PV system that later on passed through an incremental conductance (INC) algorithm to regulate the duty cycle of a dc–dc boost converter in order to ensure fast MPPT process. The PV system is integrated with the grid through an H-bridge inverter, which is controlled by a synchronous reference frame (SRF) controller. Tracking speed and steady-state oscillations of the proposed MPPT are evaluated in the MATLAB/Simulink environment and validated via a laboratory experimental setup using Agilent solar simulator and dSPACE (DS1104) controller. Results show that the proposed MPPT technique reduces the power fluctuations of PV array significantly and the tracking speed of the proposed method is 13% and 11% faster than the conventional INC and perturb and observe (P&O) methods respectively under PSCs.


2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Abdelkhalek Chellakhi ◽  
Said El Beid ◽  
Younes Abouelmahjoub

This paper develops and discusses an improved MPPT approach for temperature variation with fast-tracking speed and reduced steady-state oscillation. This MPPT approach can be added to numerous existing MPPT algorithms in order to enhance their tracking accuracy and response time and to reduce the power loss. The improved MPPT method is fast and accurate to follow the maximum power point under critical temperature conditions without increasing the implementation complexity. The simulation results under different scenarios of temperature and insolation were presented to validate the advantages of the proposed method in terms of tracking efficiency and reduction of power loss at dynamic and steady-state conditions. The simulation results obtained when the proposed MPPT technique was added to different MPPT techniques, namely, perturb and observe (P&O), incremental conductance (INC), and modified MPP-Locus method, show significant enhancements of the MPP tracking performances, where the average efficiency of the conventional P&O, INC, and modified MPP-Locus MPPT methods under all scenarios is presented, respectively, as 98.85%, 98.80%, and 98.81%, whereas the average efficiency of the improved P&O, INC, and modified MPP-Locus MPPT methods is 99.18%, 99.06%, and 99.12%, respectively. Furthermore, the convergence time enhancement of the improved approaches over the conventional P&O, INC, and modified MPP-Locus methods is 2.06, 5.25, and 2.57 milliseconds, respectively; besides, the steady-state power oscillations of the conventional P&O, INC, and modified MPP-Locus MPPT methods are 2, 1, and 0.6 watts, but it is neglected in the case of using the improved approaches. In this study, the MATLAB/Simulink software package was selected for the implementation of the whole PV system.


2021 ◽  
Vol 13 (6) ◽  
pp. 3000
Author(s):  
Catalina González-Castaño ◽  
James Marulanda ◽  
Carlos Restrepo ◽  
Samir Kouro ◽  
Alfonso Alzate ◽  
...  

This paper proposes a new method for maximum power point tracking (MPPT) of the photovoltaic (PV) system while using a DC-DC boost converter. The conventional perturb and observe (P&O) method has a fast tracking response, but it presents oscillation around the maximum power point (MPP) in steady state. Therefore, to satisfy transient and steady-state responses, this paper presents a MPPT method using support vector machines (SVMs). The use of SVM will help to improve the tracking speed of maximum power point of the PV system without oscillations near MPP. A boost converter is used to implement the MPPT method, where the input voltage of the DC-DC converter is regulated using a double loop where the inner loop is a current control that is based on passivity. The MPPT structure is validated by hardware in the loop, a real time and high-speed simulator (PLECS RT Box 1), and a digital signal controller (DSC) are used to model the PV system and implement the control strategies, respectively. The proposed strategy presents low complexity and it is implemented in a commercial low-cost DSC (TI 28069M). The performance of the MPPT proposed is presented under challenging experimental profiles with solar irradiance and temperature variations across the panel. In addition, the performance of the proposed method is compared with the P&O method, which is traditionally most often used in MPPT under demanding tests, in order to demonstrate the superiority of the strategy presented.


Algorithms ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 24
Author(s):  
Diogo Remoaldo ◽  
Isabel Jesus

This paper presents the results obtained for the maximum power point tracking (MPPT) technique applied to a photovoltaic (PV) system, composed of five solar panels in series using two different methodologies. First, we considered a traditional Perturb and Observe (P&O) algorithm and in a second stage we applied a Fuzzy Logic Controller (FLC) that uses fuzzy logic concepts to improve the traditional P&O; both were implemented in a boost converter. The main aim of this paper is to study if an artificial intelligence (AI) based MPPT method, can be more efficient, stable and adaptable than a traditional MPPT method, in varying environment conditions, namely solar irradiation and/or environment temperature and also to analyze their behaviour in steady state conditions. The proposed FLC with a rule base collection of 25 rules outperformed the controller using the traditional P&O algorithm due to its adaptative step size, enabling the FLC to adapt the PV system faster to changing environment conditions, guessing the correct maximum power point (MPP) faster and achieving lower oscillations in steady state conditions, leading to higher generated energy due to lower losses both in steady state and dynamic environment conditions. The simulations in this study were performed using MATLAB (Version 2018)/Simulink.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fahd A. Banakhr ◽  
Mohamed I. Mosaad

AbstractSolar photovoltaic (PV) energy has met great attention in the electrical power generation field for its many advantages in both on and off-grid applications. The requirement for higher proficiency from the PV system to reap the energy requires maximum power point tracking techniques (MPPT). This paper presents an adaptive MPPT of a stand-alone PV system using an updated PI controller optimized by harmony search (HS). A lookup table is formed for the temperature and irradiance with the corresponding voltage at MPP (VMPP). This voltage is considered as the updated reference voltage required for MPP at each temperature and irradiance. The difference between this updated reference voltage at MPP and the variable PV voltage due to changing the environmental conditions is used to stimulate PI controller optimized by HS to update the duty cycle (D) of the DC–DC converter. The temperature, irradiance, and corresponding duty cycle at MPP are utilized to convert this MPP technique into an adaptive one without the PI controllers' need. An experimental implementation of the proposed adaptive MPPT is introduced to test the simulation results' validity at different irradiance and temperature levels.


2020 ◽  
Vol 12 (9) ◽  
pp. 3763 ◽  
Author(s):  
Jong-Chan Kim ◽  
Jun-Ho Huh ◽  
Jae-Sub Ko

This paper presents an optimal design of a fuzzy control rule base for tracking the maximum power point of a photovoltaic (PV) system. Fuzzy control is used for the maximum power point tracking (MPPT) of PV systems because it has the advantage of processing nonlinear systems. The rule base of fuzzy control depends on the user or designer’s experience and determines the fuzzy control’s performance. In this paper, we divide the MPPT state of the PV system into four cases according to the operating conditions, and propose the rule base design of the fuzzy control according to each case. The proposed method in the paper tests the MPPT performance using artificial lighting and compares the results with the conventional control method (proportional and integral (PI) and perturbation & observation (P&O) method) to prove its effectiveness.


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