Photovoltaic System Components Research Articles

A novel acid-free combined technology to achieve the full recovery of crystalline silicon photovoltaic waste

To achieve the global carbon neutrality commitment, photovoltaics, a clean and renewable source of energy, is increasingly deployed. Photovoltaic panels are core components of photovoltaic systems. As these panels reach the end of their life, recovering the photovoltaic waste becomes crucial. Currently, strong acid reagents are commonly used in the recovery of silver from crystalline silicon photovoltaic waste, posing environmental risks and restricting the industrialization of their recycling. In this study, a novel acid-free technology to achieve the full recovery of crystalline silicon photovoltaic waste was proposed. A pyrolysis process was first conducted for decapsulation, with carbon dioxide being the main gas component at 60.64 %. Next, bioleaching technology was employed to leach silver from waste crystalline silicon photovoltaic cells. The silver leaching rate in a single leaching cycle reached 44.7 %. Meanwhile, the mechanism of silver leaching was further analyzed. Finally, high-velocity fluid frictional separation, a technique that uses high-speed fluid flow to separate material, was chosen to obtain silicon wafers. The reclaimed silicon samples had a total thickness variation of 6.64 µm to11.62 µm, with average carrier lifetimes exceeding 4.9 µs, higher than that obtained by wet etching. This study is expected to advance the industrialization of the recovery of photovoltaic waste, which is also beneficial for the sustainable development of the photovoltaic supply chain.

Reliability and criticality analysis of a large-scale solar photovoltaic system using fuzzy-fault tree analysis approach

Over time, solar Photovoltaic (PV) systems experience a decline in performance and reliability due to various environmental factors. Fault Tree Analysis (FTA) can be used to assess the reliability of these systems and identify faults and failure modes that can significantly impact the entire PV system’s performance. However, in practice, obtaining accurate failure probability values for the components of a solar PV system is challenging since systems operate in an ever-changing environment, resulting in a scarcity of data for statistical estimation. This paper proposes a fuzzy theory-based FTA approach to obtain the failure probabilities of the faults more accurately. The Fuzzy-FTA methodology converts experts’ subjective opinions expressed in linguistic terms into a Failure Possibility Score (FPS), which is then converted into a failure probability value. The results of the proposed approach are compared to those obtained through the conventional FTA to assess its effectiveness, applicability, feasibility, and efficiency. Soiling, dust accumulation, inadequate system maintenance, bad system configuration, bird dropping, delamination, improper installation, shading, grounding, and discoloration are the most critical faults and impact on the performance and reliability of solar PV systems.

Leakage current suppression methods for single-phase photovoltaic inverters

Given the swift expansion of the worlds population and economy, the decline in environmental quality caused by global warming, frequent climate disasters, ecosystem damage, sea level rise and other problems makes the world energy structure is changing, which means many countries start to develop their new energy industry and technology in order to meet their growing demand for energy. Therefore, promoting the energy transformation and innovation has become a new focus, and photovoltaic (PV) power generation as a green energy source is the focus of attention. PV inverters are essential components of photovoltaic array systems since they are the principal equipment capable of converting the fluctuating DC voltage produced by solar panels into mains frequency alternating current. However, the leakage current problem appeared during its operation has become one of the most important focuses of electrical engineers in recent years. This paper takes three aspects which is topology, filter and modulation mode to discuss how to suppress common mode leakage current in inverters. This paper reviews the existing research results and looks forward to their future development trends, which provides a reference for the following research.

Development of generalized photovoltaic model using ISIS-PROTEUS

Photovoltaic (PV) energy is a form of renewable energy that generates electricity from sunlight. PV systems consist of solar cells, which convert sunlight into electricity using a process known as the photovoltaic effect. Modeling and simulating PV systems involves using mathematical and computational models to predict the behavior and performance of PV systems under various conditions. This can include modeling the electrical characteristics of solar cells, as well as the interactions between multiple cells in a PV module or system. Following this sense, we present in this work a novel implementation of a generalized PV model using ISIS Proteus software. Proteus is layout software for electronic circuit simulation, schematic capture and PCB design. Some studies have indeed taken this context to model the PV modules either by using a Proteus Spice model of the photovoltaic panel without including the effect of climatic conditions variation, or by using pure mathematical relations that describe all physical and environmental parameters which will lead to a static behavior. The developed model in this paper as it is generalized, can be typically used as a PV cell, module even a generator for a complete simulation of a PV system. PV cell, which is the elementary component of PV system, is modeled using the single diode equivalent circuit (SDM) also known as five-parameter model and its behavior is simulated in details. The most advantage in our study is the fact that the PV output can be obtained wherever what solar radiation and ambient temperature where PV module is operating. Our model gives also the possibility to simulate a dynamic behavior under any climatic conditions. The accuracy between obtained results of simulation and the experimental data confirm the reliability and the high performance of the developed model.

A Reliability and Risk Assessment of Solar Photovoltaic Panels Using a Failure Mode and Effects Analysis Approach: A Case Study

Solar photovoltaic (PV) systems are becoming increasingly popular because they offer a sustainable and cost-effective solution for generating electricity. PV panels are the most critical components of PV systems as they convert solar energy into electric energy. Therefore, analyzing their reliability, risk, safety, and degradation is crucial to ensuring continuous electricity generation based on its intended capacity. This paper develops a failure mode and effects analysis (FMEA) methodology to assess the reliability of and risk associated with polycrystalline PV panels. Generalized severity, occurrence, and detection rating criteria are developed that can be used to analyze various solar PV systems as they are or with few modifications. The analysis is based on various data sources, including field failures, literature reviews, testing, and expert evaluations. Generalized severity, occurrence, and detection rating tables are developed and applied to solar panels to estimate the risk priority number (RPN) and the overall risk value. The results show that the encapsulant, junction box, and failures due to external events are the most critical components from both the RPN and risk perspectives. Delamination and soiling are the panels’ most critical FMs, with RPN values of 224 and 140, respectively, contributing 16.2% to the total RPN. Further, moderately critical FMs are also identified which contribute 56.3% to the RPN. The encapsulant is the most critical component, with RPN and risk values of 940 (40.30%) and 145 (23.40%), respectively. This work crucially contributes to sustainable energy practices by enhancing the reliability of solar PV systems, thus reducing potential operational inefficiencies. Additionally, recommendations are provided to enhance system reliability and minimize the likelihood and severity of consequences.

Performance analysis of PVSyst based grid connected photovoltaic systems in Pakistan compared to SAARC countries

Electricity demand increasing day by day with the passage of time, fossil fuels and traditional electricity sources are becoming obsolete. The possibility of dealing with a power deficit and importing oil and gas for electricity generation exists for developing nations like Pakistan. One of the most accessible and affordable sources of renewable energy in the world is solar power generating. Photovoltaic (PV) cell performance is influenced by the environment and the technology used to capture the available energy. The Islamabad region of Pakistan is blessed with an average of 300 days of sunshine a year due to its location in the solar band at 33.7215°N latitude and 73.0433°E longitude. The current study compares and contrasts how Pakistan and South Asian Association for Regional Cooperation (SAARC) countries generate electricity using solar systems. Choosing one geographical place from all SAARC nations, PVSyst software is used to develop and estimate the performance study for solar model cell Panasonic 320Wp, 48V and 1.5 kW Inverter Fronius for a 9.6 kWp load. Energy supplied into the grid is studied together with various losses that occur in the system, with the choice of PV arrays and other factors remaining the same for comparison study of all SAARC countries. The approach to minimize losses through the utilization of an adjustable tilt angle has been implemented. This study will be useful in estimating and planning the solar energy output in all SAARC nations for the same photovoltaic system, and it will be simple to trade all PV system components in the region.

Design and analysis of L and LCL filters for grid-connected HNPC inverters used in renewable energy systems

With the widespread integration of renewable energy systems (RES) into the electric grid, maintaining power quality within specified limits has become a major focus. The total harmonic distortion (THD) value of the currents transferred to the grid and directly affecting power quality in (RES) such as grid-connected photovoltaic (PV) and fuel cells (FC) should not exceed 5%. To achieve this objective, various filter topologies are used to interface between the inverters, which are components of PV and FC systems, and the grid.Although there are numerous filter topologies, L and LCL-type passive filters are the most commonly used topologies in grid-connected systems. This study analyzes the L and LCL-type filter topologies for the H-bridge neutral point clamped (HNPC) inverter. The study’s modeling was carried out in the MATLAB/Simulink®. By comparing the simulation results, L and LCL filters’ harmonic attenuation capabilities, maximum power transferred to the grid, and effects on grid current have all been investigated.

An autonomous photovoltaic system sizing program for office applications in Africa

none

Availability evaluation of solar photovoltaic systems using markov modeling and cuckoo search algorithm

The main objective of present investigation is to evaluate and optimize the operational availability of the solar photovoltaic systems. As the solar energy is a prominent source of renewal energy and contribute a lot in global development having less environmental impacts but the safety and reliability issues of these systems also observed during the operational phase. Availability is an effective tool that is used to discourse the safety and performance issues of renewal energy sources especially solar photovoltaic systems. Here, a stochastic model is developed for solar photovoltaic system having solar photovoltaic plates, solar charger, solar battery, and inverter. The Markov birth-death process is applied for development of the mathematical model of the proposed system. The chapman-Kolmogorov differential difference equations of the proposed solar photovoltaic system used to predict the steady state availability of system. On the basis of literature, the failure and repair rates of all components of solar photovoltaic system are considered as exponentially distributed. In addition, an effort is also made to predict the optimum availability of solar photovoltaic system using well-known optimization technique cuckoo search algorithm. It is revealed that, the predicted availability of the solar photovoltaic system is 0.9988799 at population size 60 after 700 iterations. The estimated parametric values of the failure and repair rates also derived. To highlight the importance of the study the numerical and graphical results are presented and shared with the system designers and maintenance engineers.

Smart Grid Resilience for Grid-Connected PV and Protection Systems under Cyber Threats

In recent years, the integration of Distributed Energy Resources (DERs) and communication networks has presented significant challenges to power system control and protection, primarily as a result of the emergence of smart grids and cyber threats. As the use of grid-connected solar Photovoltaic (PV) systems continues to increase with the use of intelligent PV inverters, the susceptibility of these systems to cyber attacks and their potential impact on grid stability emerges as a critical concern based on the inverter control models. This study explores the cyber-threat consequences of selectively targeting the components of PV systems, with a special focus on the inverter and Overcurrent Protection Relay (OCR). This research also evaluates the interconnectedness between these two components under different cyber-attack scenarios. A three-phase radial Electromagnetic Transients Program (EMTP) is employed for grid modeling and transient analysis under different cyber attacks. The findings of our analysis highlight the complex relationship between vulnerabilities in inverters and relays, emphasizing the consequential consequences of affecting one of the components on the other. In addition, this work aims to evaluate the impact of cyber attacks on the overall performance and stability of grid-connected PV systems. For example, in the attack on the PV inverters, the OCR failed to identify and eliminate the fault during a pulse signal attack with a short duration of 0.1 s. This resulted in considerable harmonic distortion and substantial power losses as a result of the protection system’s failure to recognize and respond to the irregular attack signal. Our study provides significant contributions to the understanding of cybersecurity in grid-connected solar PV systems. It highlights the importance of implementing improved protective measures and resilience techniques in response to the changing energy environment towards smart grids.

High Gain Zeta Converter with ANFIS Based MPPT for Standalone Application with Galvanic Isolation

The installation of Photovoltaic (PV) systems is steadily increasing globally, as they stand as the primary means of accessing the electrical grid. A considerable amount of effort is dedicated to ensuring the optimal functioning of these PV systems. As a result, the goal of this proposed work is to achieve stable DC-link voltage of the ZETA Converter using the ANFIS MPPT strategy. In this proposed approach, a ZETA converter is used, which results in improved voltage gain and reduced ripple content of the output voltage and current. An isolation transformer is integrated into the system to provide galvanic isolation. This transformer enhances safety by isolating the output from the high-frequency converter from the PV system and other components. Galvanic isolation prevents the transmission of electrical faults and protects connected loads. The output from the isolation transformer is supplied to a DC load through a rectifier. The diode bridge rectifier converts the alternating current (AC) output from the transformer into direct current (DC), making it suitable for powering DC loads. To stabilise the converter’s output voltage and mitigate the intermittent nature of PV, an intelligent MPPT is used, which also aids in maintaining DC-link voltage without distortions and ripples from the converter. The entire paper is validated through a MATLAB simulation 2021a.

Synergistic effect on silicon surface under low energy he ion irradiation at elevated temperatures

One of the major challenges in nuclear fusion, nanolithography, and various industries is the effect of low energy ion irradiation on the surface morphology of materials. For example, the effect of low energy irradiation on plasma-facing materials' lifetime in fusion reactors, the effect on the optical systems in nanolithography laser produced plasma devices, and the effect on mass production of effective and flexible anti-reflecting coatings in photovoltaic (PV) industry. Silicon and carbides in particular, showed interest in nuclear fusion as potential wall materials, as in mirror designs for nanolithography devices, and as coatings in PV system components. Recently innovative novel Si nanostructures such as nanocones (NCs) demonstrated great feasibility in several areas including the next generation PV cells, batteries, supercapacitors, nano-optoelectronics, photonics, and energy storage devices. Their unique electronic properties and significantly higher absorption over a wide broadband range, offer paramount potential in various fields including microelectronics, optoelectronics, photonics, photovoltaics, biology, sensors, templet for selective growth (on nanostructured substrates), fast electronic devices, and even in high- density data storage. We tailor Si NCs using simultaneous low energy helium (He) ion irradiation on planar Si (111) and (100) and Ta metal masks. In a series of successive experiments, three key parameters, temperature, flux, and presence of Ta metal impurity, were tuned to study the progression of nanostructure development, as well as the effect of these nanostructures on key material properties. Before performing He ion sputtering experiments, 100 eV Ar+ ion irradiations, for 10 min duration, were also performed in-situ in each case for removing any preexisting SiO2 form planer Si substrates. Clear and distinctive progressions of NC development were found during the tuning of each parameter. During the temperature dependent studies, we clearly observed a sequential progression from thicker and less dense cones (773 K) to finer and more densely packed NCs (1073 K). On the other hand, during the case of flux dependent studies, it was found that increasing flux increases the size of the NCs, with low flux resulting in sparsely placed nanodots, and high fluxes resulting in large conglomerates. Finally, the effect of Ta impurity shows an increased propensity for NCs development. In addition, using optical-reflectivity studies we clearly observed a significant reduction (from ∼65 to almost zero) in optical reflectivity.

Assessment of Energy Conversion in Passive Components of Single-Phase Photovoltaic Systems Interconnected to the Grid

This paper presents a mathematical analysis of how energy return in grid-connected single-phase photovoltaic systems affects the sizing of passive components. Energy return affects the size of the link capacitor, making it larger than reported in the literature. One of the main points of this article is that an inverter connected to the grid using a DC–DC converter with an appropriate link capacitor is analyzed. The energy return is caused by the value (in Henry units) of the L-filter, which is also analyzed in this paper. The analysis shows that there is a link between the value of the L-filter and the voltage of the DC bus. The analysis assumes two conditions: (1) the DC bus voltage is always higher than the peak value of the grid sinusoidal voltage, and (2) there is a unity power factor at the connection point between the grid and the L-filter. To operate in an open loop, a compensation phase angle is calculated and introduced in the single-phase inverter modulation; this phase angle compensates the phase shift caused by the L-filter, avoiding the use of a phase-locked-loop (PLL) control system. The L-filter ripple current is evaluated by Fourier analysis, and the DC bus ripple voltage is evaluated by considering the energy returned to the link capacitor. The results of the analyses are compared with existing methods reported in the literature. The results also show that, to minimize the value of the L-filter, the DC voltage must be almost equal to the maximum voltage of the grid. Equations to assess the value of the DC-link capacitor and the L-filter in function of their ripples are developed. The results were verified with simulations in Simulink and experimentally.

Thin film luminescent solar concentrators fabricated for indoor applications

The luminescent solar concentrators are considered a promising photovoltaic solution to improve the energy efficiency of building structures. The main role of these devices is to provide a novel route for harnessing solar radiation with designs in the form of semi-transparent glazing systems that could be used for building-integrated photovoltaic system or interior furniture components. Herein, we reported the fabrication and characterization of thin-film LSC devices formed with different lightguides containing Eosin Y, Safranin O dyes and the two-dye mixture. Under indoor illumination condition, the two-dye mixture LSC has a power conversion efficiency of 0.22%, which is greater than that of the single-dye LSCs. Moreover, the dependency of external solar parameters on incident light power are investigated. The data indicate that the dependency is best described with the two-dye mixture. Ultimately, this study might guide the studies to expand the use of the two-dye mixture thin film LSC devices for indoor applications.

Fine tuning the optoelectronic properties of Dibenzo[b,d]Furan-Centered linear hole transporting materials for perovskite solar cells

Perovskite solar cells (PSCs) have received a lot of interest recently due to their high efficiency, affordable manufacture, and band gap turn capacity. Reports on PSCs efficiency rose dramatically from its initial value of 3.8% in 2009 to 24% in 2022. The absence of suitable materials for hole transportation is a significant barrier to further improving efficiency. To be used as potential components of photovoltaic systems, we have designed a series of small molecules serving as hole transport materials (HTMs) namely MT1, MT2, MT3, MT4, MT5, and MT6 having dibenzo furan based donor core with end capped acceptor moieties linked by thiophene as a bridge. The photovoltaic and optoelectronic properties of the molecules have been investigated by comparing them to a reference molecule (R). All of the designed molecules (MT1-MT6) showed lower bandgaps (1.98 eV–2.61 eV) than reference molecule (3.81 eV), indicating improved electron density transfer. All designed molecules (MT1-MT6) have high open-circuit voltage (1.28 V–1.41 V) and downshifted peak occupied molecular orbital energies (−5.41 eV to −5.28 eV) when electron-withdrawing acceptor moieties are chosen. High dipole moments (5.18 D to 21.70 D) proved that designed molecules (MT1-MT6) are highly soluble and are anticipated to make it easier to fabricate multilayered films. All designed molecules have effective charge transport capabilities, as evidenced by the reorganization energy values. All HTMs (MT1-MT6) have higher FF (0.9032–0.9102) and superior power conversion efficiency of 27.40%–30.42% compared to R (24.62%). This study established the viability of fabricating high performance PSCs using all proposed molecules (MT1-MT6).

A Novel MPPT Technique Based on Combination between the Incremental Conductance and Hysteresis Control Applied in a Standalone PV System

A new Maximum Power Point Tracking (MPPT) method, consisting in combining the Incremental Conductance (INC) algorithm with the Hysteresis control, was developed and applied to a standalone photovoltaic (PV) system to generate the maximum power of the PV array. The INC allows one to search for the Maximum Power Point (MPP). The hysteresis improves the accuracy of tracking the MPP very fast even after severe changes in weather conditions and has no oscillations around the MPP. The five-level S-Packed U Cells (SPUC5) inverter is used to transform the produced DC voltage to AC voltage; it generates five-level output voltage with a small number of switches and only DC source voltage. The capacitors of the SPUC5 are controlled by the Pulse Width Modulation (PWM) in order to balance their voltages. The proposed PV system was established and trained in the MATLAB/Simulink environment under various irradiation conditions. A comparison between different MPPT methods, INC-PWM and INC-PI, was investigated in order to examine the effectiveness of the developed MPPT technique in particular, and of all the PV system components. The results of the simulation validate the effectiveness of the suggested MPPT algorithm as well as the used SPUC5 inverter.

Automated Solar PV Simulation System Supported by DC–DC Power Converters

Solar photovoltaic simulators are valuable tools for the design and evaluation of several components of photovoltaic systems. They can also be used for several purposes, such as educational objectives regarding operation principles, control strategies, efficiency, maintenance, and other aspects. This paper presents an automated solar photovoltaic simulation system with the capability to generate automated tests considering different parameters of solar photovoltaic panels and different operation conditions. The proposed simulator is composed of three buck-boost DC–DC power converters controlled in such a way that will behave similarly to solar photovoltaic panels. It allows to introduce additional variable loads and maximum power point tracker algorithms similar to real systems. Some converters are controlled by a DSP microcontroller connected to a single programmable logic controller which generates the automated tests. Thus, using the presented solution, it is possible to implement the I-V and P-V characteristic curves of solar photovoltaic panels and evaluate different maximum power point tracker algorithms considering different meteorological conditions and load variations, being a useful tool to teach subjects related to renewable energy sources and related applications. Several simulation results using Matlab/Simulink and experimental results are presented to validate the operation of the proposed solution. Experimental results achieve a ripple between 2% and 5% of the desired average current in MPP conditions.

Reliability, availability, and condition monitoring of inverters of grid‐connected solar photovoltaic systems

AbstractReliability, Availability and Condition Monitoring (RACM) evaluation has become a critical area of interest for researchers as the output power quality of a Photo‐Voltaic (PV) system depend on the reliability of its components. In this paper, the RACM of grid‐connected PV systems is presented. For this, the Reliability Block Diagram (RBD) technique along with the exponential probability distribution function is used. The main objective of this work is to identify the weakest subsystem of a system in order to enhance system reliability. The condition monitoring system will be helpful in avoiding the sudden breakdown and unexpected maintenance of the system. An elaborate analysis is presented for PV system beginning from the sub‐assemblies to the subsystems and then to the overall system. In addition, the subsystems are ranked based on their impact on the overall availability of the system. This is decided based on the availability importance measures. It is observed that the inverter forms the weakest subsystem in the solar system. The novelty of the proposed RACM method is that one can monitor the health status or useful life of the system regularly which is not yet explored in the literature. Most of the papers have considered that the components of PV systems are non‐repairable but in this paper, the redundancy concept is explored which helps in increasing the reliability and availability of the system. When the proposed method and the results obtained are compared to existing methods, it is discovered that the proposed work outperforms them.

Analytical Assessment of Time-Varying Reliability and Penetration Limit of PV-Integrated Systems

This article presents a discrete convolution-based method for reliability evaluation of a grid-connected photovoltaic (PV) system, where special consideration is given to the variable availability of PV array components. Along with the negative impacts of variable solar irradiance and ambient temperature on the PV power generation, they affect the reliability of PV system power electronic components. A variable availability model based on the power loss in the semiconductors of PV system components is needed to account for this effect in the reliability analysis. The article proposes a 3-D capacity outage model of a PV farm that accounts for the variable availability and the redundancies associated with the topologically complex multistring PV arrays. The outage model is used to construct a PV capacity outage probability and frequency table (COPAFT), which along with conventional generation COPAFT, is convolved with the distribution of load to determine system reliability. An integration limit assessment tool is also developed within the proposed framework, ensuring that the PV power integration does not violate the system frequency stability. Simulations on the modified IEEE RTS-79 system demonstrate the efficacy of the proposed method.

Household photovoltaic systems optimization methodology based on graph theory reliability

A novel passive strategy to overcome the inconveniences of possible failure or underperformance of the components of a household scale photovoltaic (PV) system is proposed. The developed methodology is based on network reliability and determines the optimal array topology to be implemented under certain constraints through the maximization of a merit function that considers three different aspects: the total power that a structure produces, the power per panel ratio and the average reliability of the structure. Every factor is weighted through a parameter that controls its relative importance in the merit function. The restriction implemented in this study corresponds to the inherent limits in the voltage and current input of an inverter. The optimization process has been developed for several scenarios considering different decision criteria. Intuitive results are obtained when the optimization relies on the power per unit module and also when reliability is the main contributor in the merit function. When power production is preferred, structures with large number of panels prove to be the best even when they are asymmetrically connected and thus some panels are underperforming. A case study of a particular inverter has been developed to gain insight in an example, computing the optimal structure in terms of the three parameters.