Observe Maximum Power Point Tracking Research Articles

Current correction and fuzzy logic optimizations of Perturb & Observe MPPT technique in photovoltaic panel

This paper presents a two-way optimization of the Perturb & Observe (P&O) maximum power point tracking (MPPT) technique using current correction and fuzzy logic techniques. In fact, photovoltaic (PV) energy has become more and more coveted today. In the future, it will become a necessity. To ensure its optimization, maximum operating point tracking method is considered as a technological key in PV systems. One of the most used MPPT methods is the P&O technique. In this paper, we will focus on optimizing this method based on two techniques. A first attempt has been made to estimate a current correction of the P&O algorithm in case of illumination variation. Then, fuzzy logic optimization attempt had been highlighted to improve power loss. It is shown that both proposed techniques are very effective and allow considerable improvement of accuracy and are less affected by sudden variation of climatic parameters. The proposed approaches are tested via Matlab software and compared the classical P&O algorithm. Through applications, we could conclude that the two optimized proposed methods offer a remarkable improvement concerning power losses.

A Fuzzy Logical-Based Variable Step Size P&O MPPT Algorithm for Photovoltaic System

This paper presents a Modified Perturb & Observe (P&O) Maximum power point tracking (MPPT) algorithm using fuzzy logic-based variable step size to overcome some of the limitations associated with the conventional P&O MPPT tracking method to improve the transient response and reduce the steady-state terminal voltage oscillations. The proposed MPPT algorithm was implemented and tested on an indoor emulated PV source that is constructed from a conventional solar panel and a DC power supply, a boost DC-DC converter and a dSPACE-based MPPT controller. The advantage of implementing this testing platform for MPPT is easy implementation and indoor testing of MPPT algorithms and DC-DC power converters. Thus, dependency on atmospheric conditions such as irradiance level can be avoided. Details of the emulated PV source mathematical model and electrical characteristics, the proposed MPPT algorithm via dSPACE, simulation and test results were presented in the paper.

Grid Interconnected Photo Voltaic System Using Shunt Active Filter for Power Quality Improvement

Now-a-days, power generation and utilization became more complicated which further affects the economy of a country. The available non-renewable energy sources that supply the demanded power do not consider environmental challenges like global warming and pollution. This leads to the development of power generation based on Renewable Energy Resources (RES). These RES are connected to the grid through power electronic converters which offer countless power quality issues that must be rectified to deliver a quality power to the end users. The proposed work uses a three phase Voltage Source Inverter (VSI) based Shunt Active Power Filter (SAPF) fed by solar Photo Voltaic (PV) system to eliminate current harmonics at the source side of the grid. The output of the PV system is given to a boost converter along with self–lift single-ended primary-inductor converter (SEPIC) for supplying high voltage gain which is accompanied by a Perturb & Observe Maximum Power Point Tracking (MPPT).The main objective of this paper is to eliminate the current harmonics at the grid side using SAPF. Also, the proposed SAPF is used for exporting the power generated from PV to the grid. The overall system performance is validated with a help of MATLAB/SIMULINK.

Xilinx Spartan 3A DSP FPGA based DC Voltage Regulators for PV Systems

This paper explains the design and implementation of Perturb and Observe Maximum Power Point Tracking Algorithm combined with the Closed Loop Digital PI control algorithm to generate the Digital Pulse Width Modulation using Xilinx Spartan 3A DSP Field Programmable Gate Array for regulating the load voltage of DC-DC buck converter. And also concentrates on the methods for generation of DPWM techniques say Delay line based Digital Pulse Width Modulation and Hybrid based Digital Pulse Width Modulation with the 210 bit resolution. All the algorithms are developed by VHSIC Hardware Description Language coding and are implemented using Xilinx ISE 12.1 tool. The hardware results validate the satisfactory voltage regulation of PV system under continuous changing weather condition. The Hybrid based Digital Pulse Width Modulation seems to have better time transient response than the Delay line based Digital Pulse Width Modulation.

Modified Single-Phase Single-Stage Grid-Tied Flying Inductor Inverter With MPPT and Suppressed Leakage Current

In this paper, an improved transformerless single-phase single-stage grid-tied flying inductor inverter is presented. The negative terminal of the photovoltaic (PV) array is grounded in the improved topology, which increases reliability and suppresses the leakage current. The proposed topology has buck-boost capability without increasing the number of required components and has a high efficiency. An improved control algorithm for proper operation of the proposed topology which decreases switching losses has been investigated. Moreover, a perturbation and observation maximum power point tracking (MPPT) algorithm has been adapted to the proposed inverter, which does not utilize proportional-integral (PI) controllers, for the purpose of the MPPT. Furthermore, a design procedure of the passive elements of the converter based on the corresponding operating has been demonstrated. Simulation in MATLAB Simulink plus an experimental prototype is developed to reconfirm the designed results. Finally, a comparison study has been investigated for better clarification of the advantages and disadvantages of the proposed inverter.

Adaptive Neuro-Fuzzy Inference System-based Improvement of Perturb and Observe Maximum Power Point Tracking Method for Photovoltaic Systems

This paper presents a maximum power point (MPP) tracking method based on a hybrid combination between the fuzzy logic controller (FLC) and the conventional Perturb-and-Observe (P&O) method. The proposed algorithm utilizes the FLC to initialize P&O algorithm with an initial duty cycle. MATLAB/Simulink models consisting of, the photovoltaic system, boost converter and controllers, are built to evaluate the performance of the proposed algorithm. To accurately illustrate the performance of the proposed algorithm, comparisons with standalone FLC and P&O are carried out. The performance of the proposed algorithm is investigated difficult weather conditions including sudden changes and partial shading. The results showed that the proposed algorithm successfully reaches MPP in all scenarios.

An improved perturbation and observation maximum power point tracking algorithm based on a PV module four-parameter model for higher efficiency

This paper proposes a novel method to improve the efficiency of the perturbation and observation (P&O) maximum power point tracking (MPPT) algorithm. The proposed method can improve the dynamic tracking response of P&O, reduce the steady state oscillation of P&O and eliminate the possibility of the algorithm to lose its tracking direction. To estimate the optimal duty ratio of the boost converter at the maximum power point, an optimal duty ratio estimation algorithm based on a four-parameter model of a photovoltaic (PV) module is proposed. Furthermore, the ratio of the power-voltage curve slope to the current in the PV module is defined as Kpvi. Because Kpvi has a small variation range at different irradiations, a piecewise linear function dependent on Kpvi is developed to generate the optimal step size of P&O. Finally, Kpvi is utilized to avoid drift phenomenon in case of fast change in irradiation. To prove its effectiveness, the proposed P&O algorithm is compared with conventional P&O and adaptive P&O using the sudden step change test, Ropp test, and four one-day irradiation and temperature profile tests in Simulink. The proposed algorithm is also benchmarked by MPPT efficiency (ηMPPT) calculation. The results show that the ηMPPT of the proposed P&O is increased by 0.65% in one-day irradiation and temperature profile with light cloud test. In addition, the ηMPPT of the proposed P&O can be further improved up to 1.27% and 1.24% in one-day profile with heavy cloud test and one-day profile with dark cloud test, respectively. Moreover, it needs neither additional sensors nor expensive microcontrollers.

Modeling and Event-Driven Simulation of a Photovoltaic System Controlled with Two Configurations of Perturb & Observe Maximum Power Point Tracking

En este articulo se modela y simula un sistema fotovoltaico con el objeto de comparar dos estructuras de control para el seguimiento del punto de maxima potencia, lo cual se hace en dos partes. En la primera parte, el sistema se controla con el algoritmo de seguimiento del punto de maxima potencia llamado Perturbe & Observe, el cual se aplica directamente al ciclo util. Asi mismo, se obtienen resultados de simulacion que se comparan con los resultados experimentales presentandose una alta concordancia. En la segunda parte, al algoritmo de seguimiento del punto de maxima potencia se le acopla una estructura de control en modo de corriente promediada, y se comparan a traves de simulaciones la robustez de ambos sistemas ante perturbaciones. El sistema que incluye el control en modo de corriente presenta una mejor respuesta tanto en el tiempo de establecimiento como en las oscilaciones de estado permanente.

Predictive current control in multifunctional grid connected inverter interfaced by PV system

This study deals with a three-phase double-stage multifunctional grid-connected inverter interfaced with a photovoltaic system. The studied system consists of a photovoltaic array, a dc-dc boost converter and a three-phase voltage source inverter connected to the utility at the point of common coupling. To ensure the multifunctional feature, we propose a predictive current control which uses a discrete-time model of the system to predict the future value of the filter current for different voltage vectors. Selection of the optimal voltage vector aims to minimize the error between reference and predicted current by using a cost function. Then, perturb and observe Maximum Power Point Tracking is applied to the dc-dc boost converter to extract maximum power from the photovoltaic array. The main benefits of the proposed system are: harmonic and reactive current elimination, reactive power compensation and feeding photovoltaic power into the utility. The proposed control algorithm is performed on a Matlab⧹Simulink™ environment, simulation and experimental results confirm the effectiveness of the proposed control method in term of total harmonic distortion and power factor correction. The performance of the proposed control has been compared with hysteresis and direct power control strategies. Dynamic state results show that the proposed method provides a better performance and more stability under fast environmental conditions changing than hysteresis current control.

A Simple Checking Algorithm with Perturb and Observe Maximum Power Point Tracking for Partially Shaded Photovoltaic System

This paper presents a simple checking algorithm for maximum power point tracking (MPPT) technique for Photovoltaic (PV) system using Perturb and Observe (PO or in other words partially shaded condition of PV array. The results from the system using the proposed approach prove to have faster response and low ripple. Besides, the results are close to the desired outputs and exhibit an approximately 98.25% of the system efficiency. On the other hand, the system with conventional P&O MPPT seems to be unstable and has higher percentage of error. In summary, the proposed method is useful under varying level of irradiation with higher efficiency of the system.

A Review on Perturb and Observe Maximum Power Point Tracking in Photovoltaic System

Solar energy is becoming popular and has drawn lots of attention from researchers nowadays. However, the output power of the photovoltaic (PV) arrays varies with solar irradiation and temperature, which affect the efficiency of PV arrays. Therefore, Maximum Power Point Tracking (MPPT) control technique is used to extract the maximum available power from the PV arrays. Perturb and Observe (P&O) algorithm is one of the favorite techniques frequently used due to its simplicity and low cost. Yet, the conventional P&O algorithm has several drawbacks, which leads to power loss and lack of efficiency. This paper presents comparison of the basic P&O algorithm with the modified P&O algorithm used for partial shading condition in terms of complexity, accuracy, cost, and basic concept of each method.

Real-Time Digital Simulation and Analysis of Sliding Mode and P&O MPPT Algorithms for a PV System

Abstract This paper presents an integral Sliding Mode Controller (SMC) of a DC-DC boost converter integrated with a photovoltaic (PV) system for maximum power extraction. In view of improving the steady-state performance of the maximum power point tracking (MPPT), an integral of the error term is included in the sliding surface. The output of PV panels is connected to a DC-DC boost converter to regulate and enhance the voltage up to a desired level. By using SMC with integral term, the steady-state condition is obtained at less than 0.1 sec. With the proposed ISMC MPPT the maximum power extracted is more than 10% than the traditional Perturb & Observe (P&O) MPPT at standard test conditions (STC). The results obtained using the SMC are compared with that of the fixed step size P&O MPPT controller. The performances of the proposed sliding mode controller and the P&O controller are validated through experimentations using a Real-Time Digital Simulator (RTDS)-Opal RT.

IMPLEMENTATION OF MPPT ALGORITHM ON PV PANEL USING PIC16F877 CONTROLLER

This paper presents the design and practical implementation of a Boost-type power converter for Photovoltaic (PV) system for energy storage application based on Perturb and Observe Maximum Power Point Tracking (MPPT) algorithm. A Boost converter is used to regulate battery charging. The major drawbacks faced by the tracking algorithm in the conventional method of tracking is overcome by the strategic utilization of a properly controlled and programmed design of Peripheral Interface Controller which helps in achieving optimized output results of MPPT algorithm.. The system is controlled by a Peripheral Interface Controller (PIC) 16F877 controller by sensing the solar panel voltage and generating the Pulse Width Modulation (PWM) signal to control duty cycle of the boost converter. This type of microcontroller was chosen is best suited as it has the necessary features for the proposed design such as built-in Analog-to-Digital Converter (ADC), PWM outputs, low power consumption and low cost. Hardware results demonstrate the effectiveness and validity of the proposed system in order to attain satisfactory results from the method. This paper mainly focuses on the effective utilization of PIC controller in the implementation of the MPPT algorithm and its constructional features which help gain the appropriate and accurate results.

A proposed strategy for power optimization of a wind energy conversion system connected to the grid

Many strategies have been developed in last decade to optimize power extracted from wind energy conversion system where many of them can produce only 30% more than the rated power. With the considered strategy, the generated wind power can reach twice its nominal value using a fast and reliable fully rugged electrical control. Indeed, by employing a suitable control technique where the produced power in super-synchronous mode is derived from both the stator and the rotor. Also, the rotor provided power in this case grows up 100% comparing to stator rated power. However, this solution permits to maintain the wind energy conversion system operation in its stable area.The considered system consists of a double fed induction generator whose stator is connected directly to the grid and its rotor is supplied by matrix converter. In this paper, the sliding mode approach to achieve active and reactive power control is used. This latter is combined with de Perturbation and Observation Maximum Power Point Tracking used in the second operation zone. The obtained simulations results are assessed and carried out using Matlab/Simulink package and show the performance and the effectiveness of the proposed control.

Renewable Energy Based Shunt Compensator For Power Quality Improvement

This paper presents an optimal operation of Photo-voltaic (PV) system based Shunt Active Filter (PV-SAF) for harmonic mitigation and reactive power compensation. When the PV system generates excessive or equal power required to the load demand, then the coordinating logic disconnecting the service grid from the load and reduce of panel tariff and global warming gasses. The PV module is connected to the DC side of SAF through the DC-DC converter with fuzzy based Perturb & Observe (P&O) Maximum Power Point Tracking (MPPT) algorithm to eliminate the drawback of the conventional PV system. The reference currents extract by the Fuzzy logic controller based PQ control strategy. This proposed PV-SAF, if connected at the terminals of a small industry or a home or a small enlightening institution can avoid the use of interruptible power supply and individual stabilizer. A MATLAB simulink is presented to validate the advantage of the proposed system

MLPO 방법을 이용한 태양광 발전의 MPPT 제어

In this paper, robust multi-level perturbation and observation (MLPO) maximum power point tracking (MPPT) control are presented of the environmental change including the solar radiation and temperature. Because the maximum power point of the Photovoltaic (PV) is changing according to the solar radiation and temperature, the technology which traces the maximum power point in order to increase the power efficiency is recognized as the very important part. The general requirement for the MPPT is that system is simple, the cost is inexpensive, the PV tracking function and output change are small. Conventional perturbation and observation (PO) method is a simple system but there is the disadvantage that an efficiency of system becomes low. In addation, the incremental conductance (IC) control is required expensive CPU because of a large of calculations. In order to solve this problem, in this paper, the MLPO MPPT control using the method diversifying the step size according to the environment condition is presented. The validity of the MLPO method presenting from this paper is proved through analyzing the solar power generation output error at the steady state.

그림자 영향을 고려한 PV 시스템의 VPO MPPT 제어

This paper presents the variable perturbation and observation(VPO) maximum power point tracking(MPPT) control of the photovoltaic(PV) system considering the shadow influence. The output characteristics of the solar cell is a nonlinear and affected by a temperature, the solar radiation and influence of a shadow. MPPT control is a very important technique in order to increase an output and efficiency of the solar power generation. Conventional perturbation and observation(PO) and incremental conductance(IC) are the method finding MPP by the continued self-excitation vibration. The MPPT control is unable to be performed by rapid output change affected by the shadow. To solve this problem, this paper proposes the VPO MPPT algorithm which changes step size according to output variation. The response characteristics of VPO MPPT algorithm proposed in this paper compares with response characteristics of conventional MPPT algorithm about the radiation, temperature and shadow influence. The validity of the algorithm proposed in this paper prove through the results of the comparisons.

Comparative study of variable size perturbation and observation maximum power point trackers for PV systems

Perturbation and observation (P&O) maximum power point tracking (MPPT) algorithms are common in photovoltaic (PV) systems due to its ease of implementation. However, operation with fixed size perturbations results in a trade-off between speed of response and maximum power yield in the steady-state. This paper discusses the use of Fuzzy logic and non-switching zone schemes for implementing variable size perturbations for improved transient and steady-state responses. The potential performance of four different P&O algorithms is investigated by means of simulations. Experimental results are then used to verify how the computational burden of each algorithm and the processing speed of a digital signal processor (DSP) affect the performance of each method in a prototype. The best performance is achieved with a new strategy called non-switching zones in the V PV × I PV plane. The power electronics converter operates with duty cycle ( D) equal to 0 or 1, depending on which non-MPP region the system operates, pushing the operating point the fastest way possible towards the MPP region, for improved transient response. At the MPP region, a reduced Fuzzy P&O MPPT algorithm optimized for small variations around the MPP is used for reduced oscillations and increased power yield in the steady-state.

Optimization of Perturb and Observe Maximum Power Point Tracking Method

Maximum power point tracking (MPPT) techniques are used in photovoltaic (PV) systems to maximize the PV array output power by tracking continuously the maximum power point (MPP) which depends on panels temperature and on irradiance conditions. The issue of MPPT has been addressed in different ways in the literature but, especially for low-cost implementations, the perturb and observe (P&O) maximum power point tracking algorithm is the most commonly used method due to its ease of implementation. A drawback of P&O is that, at steady state, the operating point oscillates around the MPP giving rise to the waste of some amount of available energy; moreover, it is well known that the P&O algorithm can be confused during those time intervals characterized by rapidly changing atmospheric conditions. In this paper it is shown that, in order to limit the negative effects associated to the above drawbacks, the P&O MPPT parameters must be customized to the dynamic behavior of the specific converter adopted. A theoretical analysis allowing the optimal choice of such parameters is also carried out. Results of experimental measurements are in agreement with the predictions of theoretical analysis.