PV Array Research Articles

Maximum Power Point Tracking Algorithm of Photo-Voltaic Array through Determination of Boost Converter Conduction Mode

In this paper, we present a new maximum power point tracking (MPPT) algorithm that can identify whether a boost converter is operating in continuous conduction mode (CCM) or discontinuous conduction mode (DCM). The conventional MPPT algorithm assumes that the converter is always in CCM mode, even though this is not always the case. The converter can enter DCM mode due to factors such as the inductor size, irradiance and temperature conditions, voltage step size of the algorithm, and operating point of the PV array. In the proposed work, the conduction mode of a boost converter is evaluated under different conditions. The region of the I–V curve where the converter is likely to operate in DCM mode is identified and a mathematical expression developed in this work is then used to detect the conduction mode of the converter. The proposed algorithm incorporates this expression into a modified perturb and observe (P&O) algorithm. In each iteration, the algorithm first detects the conduction mode of the converter. If the converter is in DCM mode, the algorithm takes a large voltage step to force the converter back into CCM mode, i.e., into the constant current region. The proposed MPPT algorithm was tested using simulation experiments, and the results show that the proposed algorithm can significantly improve the efficiency of the MPPT process.

Study on Meta-heuristics techniques for shade dispersion to enhance GMPP of PV array systems under PSCs

Reconfiguring the photovoltaic modules in an array is one option for reducing the influence of partial shadowing circumstances, which shows the shade dispersion property on the entire photovolatic array. This paper proposes a novel meta-heuristic optimization technique named Vommi that resolves the reconfiguration process of shaded modules in a photovoltaic array. Using the proposed objective function, the major goal of this unique optimization technique is to maximize the power extracted from the shaded PV array during shading conditions. The proposed meta-heuristic Vommi optimization algorithm is compared to conventional total cross-tied, and particle swarm optimization algorithm-based configurations in terms of power at the global maximum power point, improved fill factor, power losses, execution ratio, etc. The global maximum power point of the Vommi optimization algorithm configuration delivers such as 990 W, 1283 W, 1181 W, and 1173 W, which are higher than conventional approaches during all four partial shodowing circumstances and smoother power-voltage characteristics..

Topological Analysis and Solar Grid-Tied Integration of Level Building Network Based Extendable High Power Multilevel Converter

This paper presents a new solar multilevel converter (SMLC) with closed-loop control to integrate solar PV arrays with medium voltage 3.3 kV grid. This multilevel converter produces higher number of levels in the output voltage with less usage of semiconductor switches. This solar converter utilizes only ten switches and three PV sources with equal voltage to have seven levels in the output voltage. The main motive is to have minimum switches, which reduces the count of driver circuits for a power converter. Moreover, a reduced switch converter requires less space in terms of installing the power and auxiliary components. This solar power converter comprises a solar photovoltaic (SPV) array fed level building network (LBN) nested within the six switches connected in a rectangular arrangement. The converter has two PV sources at its upper and lower ends. This solar converter is also ideal for asymmetric configurations. Moreover, the increase in solar input power is possible with more count of the LBNs. The converter switching states and operating path demonstrate the working operation of the new solar PV system. A comparison of the proposed solar converter is made with existing multilevel topologies. The system is modeled and executed in closed-loop control to showcase its effectiveness for solar power conversion. The solar converter transfers the power in varying solar conditions successfully.

Power Quality Improvement in Fifteen Level PUC Converter for Solar PV Grid-Tied Applications

A fifteen-level packed U cell (FLPUC) converter with eight active switch counts for the grid-connected solar photovoltaic (GCSPV) application is introduced in this work. This converter has eight active switches with a PV source and two floating capacitors. This topology takes an edge over conventional configurations in terms of components required to achieve fifteen levels in converter output voltage. The mode of operation and switching states of the fifteen-level PUC converter are presented in detail. The active and reactive powers (PQ) control is incorporated for a grid-connected PV configuration, which in turn helps in an independent control over power injection into the grid. The maximum power operation is achieved for the first source connected to the PV array with the perturb and observe (P&O) MPPT technique and unity power factor is attained at the AC side. The voltages of floating capacitors are balanced at reference values using proportional-integral (PI) controllers to attain proper achievement of desired output voltage levels. Performance of the FLPUC based single-phase grid-tied system is analyzed under a constant and variable solar environment. This topology is modeled in MATLAB/Simulink, and test results are validated using real-time emulator to meet the IEEE-519 standard for power quality improvement.

Rule-Based Power Management and Quality Enhancement in a Standalone Microgrid

This paper focusses on the challenges associated with solar PV-diesel generator (DG)-battery storage (BS) based microgrid operating in a standalone mode. The multi-objective and coordinate control of converters is designed and implemented to acheive power management, while maintaining operation of DG in fuel economy zone (FEZ), and increase loadability of the DG with nonlinear load. Additionally, the total harmonic distortion of DG current is maintained within 5% as per IEEE 519 standard. Moreover, the control prevents flow of negative sequence currents in the DG during single phase/double phase unbalanced faults. The state of charge (SOC) of BS is also regulated to prevent over-charging/over-discharging by regulating MPPT/off-MPPT operation of the solar PV array. The hardware implementation of control is done on the laboratory set-up to test the efficacy of the control, which concludes satisfactory performance under various scenarios, and enhanced performance as compared to contemporary algorithms.

Short Circuit Fault Detection and Protection of DC Microgrid

Abstract: Due to inherent advantages of DC system over AC system such as compatibility with renewableenergy sources, storage devices and modern loads, Direct Current Microgrid (DCMG) has been one of the key research areas from last few years. In the proposed work power has been produced by using solar pv and fuel cell which is combined on the same dc bus and given to a dc load. DC microgrid protection is an important part of power system studies. The basic think which is required for protection is to get to know, where it should be provided and which component must be used. So, to address the challenges of dc microgrid protection accurate faultdetection strategies, fault current limiting method and dc circuit breaker has been used. The electricity load of the microgrid is satisfied by the power form fuel cell, pv array and battery altogether. Initially battery is charged up to 70% and at this time bidirectional converter work as a boost converter and when battery discharges till 30 %, battery starts charging and then bi- directional converter act as buck converter and battery remain in charging mode.

Grid Impact Study of Micro-Grid with an Improved Transient Response using PV Panel in MATLAB-SIMULINK

The paper present a system that convert a power generated from a renewable resources to a source having same voltage and frequency with respect to traditional power plant. As the conventional fossil fuel resources such as Coal, Diesel, Gas etc is limited in quantity which will run out very soon. Hence all the researchers throughout the world are looking for alternative form of energy[1]. As a consequence the penetration of WIND & PV – generated electrical energy into the grid system is increasing exponentially worldwide [2]. The paper consist of PV array, boost converter, 3phase VSC Inverter, synchronous generator and utility grid. PV system has low conversion efficiency, so to improve conversion efficiency it is important for PV system to work always at its maximum power point. Maximum Power Point Tracker (MPPT) control technique is used to get maximum power as possible [3]. The voltage source inverter interface with grid and transfer an energy drawn from PV array to the grid by keeping the common voltage & frequency constant. The simulation results such as voltage, current, output power for each various combination have been recorded. The simulation has been accomplished in a Software of MATLAB Math Works.

Hardware implementation of proposed and conventional PV array reconfiguration techniques to extract maximum power under various shading conditions

SummaryThe unpredictability of partial shadowing impacts the solar photovoltaic system's performance. This results in mismatch losses, reducing the healthy PV module's power output. This paper proposes a new reconfiguration method to increase the power generation of an array by lowering the power losses. A new physical relocation technique named the magic matrix shifting (MMS) method has been introduced in this paper. This work uses MATLAB/Simulink to model a 36, 213w, 6 × 6 PV array construction. Under six different partial shading situations, the performance has been examined based on P‐V, I‐V characteristics, maximum power extraction, power loss, and percentage. For comparison purposes, conventional total‐cross‐tide (TCT) and six other reconfigurations, including sudoku (SK), optimum sudoku (OSK), zig‐zag (ZZ), magic square (MS), sky‐scraper (SS), and novel shade dispersion (NSD) have been considered.

INCREMENTAL CONDUCTANCE MPPT TECHNIQUE WITH BOOST CONVERTER

This paper involves an incremental conductance Maximum Power Point Tracking (MPPT) algorithm for solar panel output. MPPT, or Maximum Power Point Tracking, is a charge controller algorithm that is used to extract the maximum available power from a PV module under particular conditions. Maximum power point (or peak power voltage) refers to the voltage at which a PV module may output the most power. Maximum power is affected by solar radiation, ambient temperature, and the temperature of the solar cell. The output of the solar PV array is connected to DC-DC boost converter. To verify the effectiveness of the algorithm, the MATLAB/SIMULINK results are presented.

Performance analysis of a hybrid solar-driven cooler for refrigerator vehicle

This study focused on investigating the annual performance of a novel hybrid solar-driven cooling system that can be used on refrigerator vehicles. The cooling system is mainly driven by a DC compressor which is powered by a PV array, while an AC compressor which is powered by the car alternator assists the cooling system when the cooling load is higher than the capacity of the DC compressor. Detailed electrical modeling of the PV panels in the array is performed based on an algorithm that comprises a set of mathematical equations and is validated against the manufacturer's test data. The detailed transient electrical power generation of the PV array is analyzed. The effect of solar irradiation and ambient temperature on the performance of the PV modules is presented. Considering the refrigeration cycle, detailed thermodynamics and heat transfer analysis on the cycle are carried out. The effect of ambient temperature and refrigerator compartment temperature on the performance of the refrigeration cycle is investigated. It is concluded that an increase in ambient temperature decreases the performance of both the PV panel and the refrigeration cycle. While an increase in refrigerator compartment temperature increases the performance of the refrigeration cycle.

Solar Photovoltaic Parameter Extraction for Three Different Technologies Using Particle Swarm Optimization Method

Industry and academia are becoming more interested in solar energy. The problem of providing an alternative to fossil fuels and limiting the environmental damage brought on by their emissions is what has brought about this increased focus. Solar photovoltaic is the subject of a growing number of studies. The goal of the current investigation is to investigate how various technological modules namely single junction amorphous silicon (a-Si), Hetero junction with Intrinsic Thin-layer (HIT) and multi crystalline silicon (mc-Si) are affected by seasonal spectrum variation respond to Indian climatic circumstances. Compared to many other nations, the entire Indian subcontinent has a relatively distinct climate with distinct seasonal patterns. The four seasons that are considered in this study are summer, winter, monsoon, and post monsoon. The impact of each season varies on the spectrum. Such a study will be helpful to measure the parameter connected to the spectrum and assess its impact on the effectiveness of the PV array. In order to conduct accurate performance investigations, the extraction of the right circuit model parameters is essential. The estimation of the solar PV parameter is done by using Particle swarm optimization (PSO) algorithm.

Power losses in PV arrays of field-aged modules

Most of studies are focused mainly on performance degradation analysis of solar cell or categorizing PV failure modes concerning solely climate or cell-technology. However, the impact of degradation modules on output power of PV arrays remains somewhat unclear and has not been reported so far. Therefore, main task of the present work is to get a general view of mismatch effect on PV arrays output for aged panels. Photovoltaic current-voltage characteristics of the 10 individual modules at Research Unit in Renewable Energies in Saharan Medium were measured and recorded. Measurements are based on the analysis of mismatch losses due to series and parallel connection of aged PV modules. Degradation data and the analysis of the I-V characteristics indicate that the tested modules have suffered in the hot desert. Both of visual and electrical degradation data reaffirm the direct relation between observed physical degradation and output power drop. Results and analysis of the I-V characteristics and degradation data indicate that Power losses in crystalline PV modules are also due to mismatch in the I-V characteristics of these modules. The paper provides many findings that can be beneficial in further studies on design of aged PV array and development of a crystalline silicon PV module and can enable the manufacturers to prevent premature failure in desert climates.

AI-based performance optimization of MPTT algorithms for photovoltaic systems

ABSTRACT Solar models have been drawing much attention in the contemporary electricity environment. Solar energy installations employ various MPPT techniques that generate the most energy. Increasing a solar (PV) device's energy effectiveness has become a key concern for scientists. Multiple MPPT approaches that collect the most power possible using a PV array have been researched. Both primary and intermediate-type procedures will be used in most procedures. The performance and convergence velocity of such a PV device become significant depending on its practical deployment under various conditions. The energy attributes of unit sections collectively serve as the primary energy-extracting elements in specific systems, dependent upon all interior and exterior elements. Considering specific external dynamical circumstances, traditional maximal power point tracing systems will not have the required translation efficacy. For assessing the overall effectiveness of the proposed intelligent maximal power point outlining methodology in partially shaded situations having significant and dynamical variations within ambient parameters, that study contrasts its efficacy using traditional maximal power point tracing techniques.

A novel GMPP estimation technique for series parallel connected partially shaded PV array

This paper presents a novel generalized model of the PV array, its circuit equation and an algorithm for its global maximum power point (GMPP) estimation in partial shading condition (PSC). A set theory based approach is proposed to develop equations in terms of voltage and current of strings and array of the generalized model of series parallel PV configuration under partial shading condition. Further, a mathematical expression for the iteration voltage is derived based on a generally observed property of local maximum power point (LMPP). The proposed GMPP estimation algorithm converges fast by simultaneous elimination of non-potential sections and subsections of the power-voltage curve of an array. Robustness of the proposed method for GMPP estimation is tested by considering 2000 no. of random shading patterns generated by MATLAB for two different PV array. Comparisons with the other existing methods in terms of accuracy and computational time of the GMPP estimation show the competitiveness of the proposed method. Experimental validation of the proposed method is carried out in the laboratory. The simulation and experimental results show that the proposed method for the GMPP estimation of a PV array under PSC is better and will be helpful for PV professionals.

Implementation of PV Based Multilevel Inverter to Improve Power Quality using Fuzzy PI and PSO PI Controllers

Power quality is the primary issue to be taken into consideration in modern electrical systems, particularly on the distribution side, to protect sensitive loads. Long-term uses can never run out of renewable resources. Connecting STATCOM at the distribution side enhances the power factor by improving the quality of the current waveform. The reactive power range that needs adjustment by utilising PV arrays on the STATCOM's DC side. Increases due to the large rise in terms of the PV power plants' size and capacity. Cascaded H Bridge multilevel topologies can increase the flexibility and effectiveness of PV modules. The suggested approach in this paper gives outcome of reduced peak over shoot, rise time, settling time, steady state error, percentage of ripples and total harmonic distortion which improves the power quality. PV system with cascaded H bridge multilevel inverters STATCOM for harmonic suppression and to make reactive powerless. To produce modulation indices for H Bridge switching, synchronised reference frame theory is modified. H bridges' average DC voltage is managed by a PI controller, and controller gains are obtained using fuzzy, PSO, and the trial-and-error approach. To confirm the viability of the suggested approach, simulation results using MATLAB/SIMULINK are shown. The experimental setup of proposed method is carried out to validate the inverter response.

An Adaptive Maximum Power Point Tracker for Photovoltaic Arrays Using an Improved Soft Computing Algorithm

This paper presents an improved version of the firefly algorithm (FA) by which a maximum power point (MPP) tracker was developed to track down the global maximum power point (GMPP) of a partially shaded photovoltaic module array (PVMA). As the first step, our team developed a high-voltage step-up converter where a coupled inductor was used to store the energy so that the duty cycle can be reduced so as to raise the voltage gain. The single-peaked P-V output characteristic curve of a PV array turns out to contain multiple peaks when the array is partially shaded. As a consequence, conventional MPP trackers occasionally track down a local maximum power point (LMPP), instead of the desired GMPP, and the output power of the array falls accordingly. Therefore, an improved version of the FA is proposed as a way to ensure that the GMPP can be tracked down in a more efficient way. Using the Matlab software, the MPP tracking performance of the proposed tracker was finally simulated in five scenarios. As it turned out, the proposed converter provided a high voltage gain at a relatively low duty cycle, and the improved version of the FA outperformed the original in terms of tracking time.

Fuzzy logic control based maximum power point tracking technique in standalone photovoltaic system

This study describes the development of a smart technique for tracking the highest power point on a standalone photovoltaic (SAPV) system when temperature and irradiance conditions are changing using fuzzy logic control (FLC). The PV systems comprises of a PV array, a boost converter, a controller for tracking the maximum power point, and an inverter to power the AC loads. The FLC-based maximum power point tracking (MPPT) is proposed because the technique is not complex and does not need a deep comprehension of the particular model of the system. Furthermore, the technique is efficient and fast response in tracking maximum power (MP) from the PV array. The technique overcame the limitation of the conventional MPPT technique that resulted in slow tracking of the MP and was not accurate on the optimal position of the PV array output power. The SAPV system is integrated with the sealed lead acid (SLA) battery bank as an alternative power source and makes up for power shortages by supplying energy to the load without interruption during power shortages. A system for managing the battery has been included in the system to preserve the battery's longevity by controlling the battery's charging process. The PV system is able to supply single-phase output AC voltage of 230 Vrms and has low total harmonic distortion (THD) that is suitable for home appliances. The achieved simulation results demonstrate the effectiveness of the suggested fuzzy logic controller in tracking the MPP.

Modeling and simulation of integrated solar PV - hydrogen systems

This work provides a novel model for solar PV – hydrogen (H2) systems that uses weather data and electrical variables of the components to perform PV-H2 design for different hybrid configurations. The objectives are to size and operate the systems optimally to reach a target production (QH) and minimize cost of H2. The component sizes and hydrogen production (QH) are optimized by PV-EL direct coupling where the EL curves are determined by the number and area of EL cells connected to PV modules. The use of maximum power point (MPP) tracking increases the coupling factor (and QH), but this gain is not significant vs. optimal PV-EL coupling. Battery assisted electrolysis has the advantage of reducing the EL size, showing how convenient is also to operate it at part loads (e.g., at night) so that the PV array and EL are larger to grant H2 production, but the batteries are much more effective. The optimal configuration, design and operation will finally depend on the evolution of unit cost of the components (PV, MPPT, EL and batteries): direct coupling leads to a cost production of 5.03 Є/kgH2 with 26 (20 cm2) EL cells per PV module; this is slightly increased by MPPT use (5.20 Є/kgH2) and notably reduced with batteries (4.07 Є/kgH2), but MPPT would be optimal if cost drops to 1/5 of base prices considered in this work and batteries are not favorable if cost per m2 of EL is reduced to less than 1/3 (depending on MPPT cost).

인공 신경망 예측기를 이용한 새로운 데이터 모델 기반 PV 어레이 고장 진단용 기준 신호 발생 방법

The power supply part of a PV system is called a PV array which is composed of many PV strings connected in parallel. A PV-string which is a set of PV modules is made by serial connection of many PV modules. PV modules presents irregularity of ouput power which is generated due to various factors such as average performance degradation of about 0.923% to 1.54% according to various researches and born power variations over production stages. Power degradation and born power variation are due to various factors such as material interactions(connection state of connectors between PV cells, corrosion, browning of encapsulation materials ...etc) and environment factors such as shading and soiling which refers to the accumulation of snow, dirt, leaves and bird droppings on PV modules. Such various minor factors can make side effects in safety side and economic one. Therefore several methodology for diagnosis of PV-array have been developed, which are classified into three types – image-based diagnosis approach, model-based approach and data-driven approach. In this paper, a new data-based approach(called data model) with good failure diagnosis reliability and economy is proposed, and verified by simulation using Python, published data and reasonable data generation. Based on the bathtub failure rate function, the fault diagnosis model requires a well-functioning predictor to generate a reference signal which evaluates the output characteristics of PV array under instantaneously varying environmental condition such as solar irradiance, temperature, etc. To implement a new data-based approach, an Artificial Neural Network (ANN) based predictor is applied as a reference generator for PV array’s fault diagnosis. r² value and the RMSE(Root Mean Square Error) are used to evaluate how far away individual learned predictions are from the actual measured values. Based on the reliability obtained from the learning result for a specific PV string, it is confirmed through pair comparison analysis(called t-test) that the learning result(called clustering possibility) between PV strings under different installation conditions is also reliable.

Optimization of Image Processing Based MPPT Algorithm Using FSO Algorithm

An image processing-based Firebug Swarm Optimization (FSO) algorithm is developed in this article to detect maximum power point tracking (MPPT) under shadowing conditions on PV arrays. After capturing an image and applying image processing techniques, the proposed method can detect the shading portion of photovoltaic array (PV). The image processing results can then be used to modify the current rating in power equations. The Firebug swarm optimization (FSO) algorithm is metaheuristic algorithm that identifies and controls switching configurations under partial shading patterns by detecting the maximum global peak point (GPP) of output power generated by multiple configurations. This research is proposed with an image processing edge detection algorithm called the Otsu-Canny algorithm for detecting the partial shade on PV array. The FSO algorithm is used to rearrange the shaded photovoltaic array to significantly reduce the power and efficiency losses. MATLAB simulations were carried out using a 280 W PV panel to verify the efficiency of the proposed FSO MPPT technique with an image processing-based algorithm. The proposed FSO MPPT scheme’s performance is compared to current cutting-edge MPPT methods. Under partial shading conditions, the proposed algorithm successfully detected the maximum peak point of a photovoltaic array, increasing power output and efficiency.