Maximum Power Voltage Research Articles

New Intelligent Fault Diagnosis (IFD) approach for grid-connected photovoltaic systems

The present work brings a new intelligent algorithm for PV system’s diagnosis and fault detection (IFD). At this stage of the study, this algorithm can detect and identify three recurrent cases between healthy and short circuit faults, as well as string disconnection in PV array using artificial neural networks (ANN). Both, detection and isolation are simple and fast. The developed model requires small training period and is based on only four inputs: the maximum power current and voltage from the output current-voltage (I–V) characteristic, the solar irradiation and the cell temperature. Experimental validation of the proposed IFD has been carried on small grid connected PV generator (PVG). The obtained results demonstrate that this approach can precisely detect and classify the existing faults with high accuracy (98.6%).

Three‐port DC–DC converter based on quadratic boost converter for stand‐alone PV/battery systems

In this study, a three-port DC–DC converter is proposed based on quadratic boost converter. The proposed converter contains paths to enable the flow of power from input source to load and battery. Furthermore, it makes a path available to energise the load by the battery. The proposed converter has a bidirectional path using two additional switches and two diodes. Power flows from the input source and the battery to the load in a single-stage resulting in higher efficiency. The proposed converter has three switches and two duty cycles defined. By adjusting the duty cycles, maximum input power and output voltage can be regulated based on the input source power and the battery condition. To control the proposed converter, three operation modes are defined. In order to design the control system, the proposed converter is analysed and the small-signal models are obtained. Using a decoupling network for the integrated small-signal models, separated closed-loop controllers are designed. Finally, a prototype for the proposed converter is prepared to validate feasibility and effectiveness of the proposed converter and the control method by experimental results.

Treatment of mixed dairy and dye wastewater in anode of microbial fuel cell with simultaneous electricity generation.

Microbial fuel cell (MFC) is a green technology that converts the stored chemical energy of organic matter to electricity; therefore, it can be used for wastewater purification and energy production simultaneously. In this study, three kinds of dairy products, including milk, cheese water, and yogurt water, were mixed with Acid orange 7 (AO7) as the model wastewater and used as the anolyte of an MFC. The capability of the system in energy production and dye removal was also investigated. The FESEM images were used to investigate the biofilms attachment to the anodes. Moreover, the polarization curves, electrochemical impedance spectroscopy, cyclic voltammetry (CV), voltage-time profiles, and coulombic efficiency were used to evaluate the electrochemical activity of the MFCs. Based on the CV results, the biofilm formation significantly improved the electrochemical activity of the electrodes. Maximum power density, voltage, and coulombic efficiency were obtained as 44.05mW.m-2, 332.4mV, and 1.76%, respectively, for cheese water + AO7 anolyte, but the milk + AO7 MFC produced a stable voltage for a long time and its performance was similar to the cheese water + AO7 anolyte. Maximum COD removal and decolorization efficiencies were obtained equal to 84.57 and 92.18% for yogurt water + AO7 and cheese water + AO7 anolytes, respectively.

Improvement of Photovoltaic Module Efficiency using Spiral Absorber and Water

This study presents an experimental investigation intended to improve the power output of a photovoltaic (PV) module using a spiral absorber and water as coolants. This cooling system, known as a photovoltaic thermal (PVT) water collector, can generate thermal (hot water) and electrical energy simultaneously. Results show that by adding coolants, the maximum power and open circuit voltages are improved; hence, the output power also increases. In addition, the power generated increases with the addition of solar radiation, and PV module efficiency becomes slightly higher than that of the PV module without cooling. The electrical characteristics of the PV module are represented by plotted current–voltage and power–voltage curves.

An efficiency-based multi-state system for reliable power delivery combining renewable sources

This paper presents a solar-wind-battery uninterruptible power supply system, which improves reliability issues at the same time that reduces the electric energy bill. The system allows transparent commutation/combination among generators using a DC diode-based OR-gate scheme taking advantage of the renewable-sources nature and avoiding complex synchronization algorithms for the AC regime. The use of a diode-based structure is justified because an efficiency analysis shows that the associated efficiency of the scheme is close to 96%. Given the geographical location, the use of the solar resource is prioritized over other generators, whose operating voltage is therefore adjusted using DC/DC converters. Since a solar panel maximum power voltage is in fact a dynamic parameter, a fuzzy-logic controller is implemented to adjust the DC/DC converters output, which in turn minimizes grid consumption. Testing results show that the controller works properly with high accuracy and precision. Since reliability and grid consumption reduction are targeted, an automatic configuration agent is incorporated to operate the system in one of four predefined states. In tests spanning a complete day with blackout scenarios, the system can provide about 40% more energy to the users with a total grid consumption reduction close to 30%.

Stand‐alone multiple input photovoltaic inverter for maximum power extraction and voltage regulation under mismatched atmospheric conditions

In this study, a single-phase multi-input photovoltaic (PV) inverter has been proposed for simultaneously achieving maximum power extraction and load voltage regulation under various operating scenarios involving weather intermittency and dynamic loading. This is achieved by maintaining the PV modules in series for similar atmospheric conditions and by allowing isolated operation of individual modules during mismatched atmospheric conditions among different modules. The weather-dependent operation of the modules allows efficient extraction of maximum power from all the modules by avoiding the modules to operate at the least maximum power point (MPP) among them, which has been a limitation of classical techniques aiming at MPP with multiple modules. A comprehensive analysis of the proposed inverter topology and its associated synchronous reference frame-based control scheme has been carried out by considering a wide range of operating scenarios in terms of (i) maintaining the operation closer to MPP under varying irradiance levels and temperature; (ii) regulated output voltage for load variation. The appropriateness of the scheme has been compared with the existing state-of-the-art topologies. In addition to the MATLAB simulation, validation has been carried out on a 300 W laboratory prototype.

A Novel Fixed PV Array Configuration for Harvesting Maximum Power From Shaded Modules by Reducing the Number of Cross-Ties

Partial shading is one of the main obstacle for constant power generation from solar photovoltaic (PV) systems. Partial shading conditions (PSCs) may be caused by passing of clouds, buildings, trees, bird litters, dust and etc. Due to PSCs, PV modules will experience the mismatching power losses which will lead to the loss of power generation capability and it also produces several peaks in the P- V curve. In order to avoid the problems associated with PSCs, the PV configuration is one of the best solution. The main objective of this research article is to model and simulate the proposed 7×7 Tripe-Tied (TT) PV array configuration along with the Series (S), Series-Parallel (SP), Total-Cross-Tied (TCT), Bridge-Link (BL), Honey-Comb (HC) configurations under various shading scenarios. The performance above-mentioned PV array configurations are evaluated under uniform, corner, center, right side end, frame, random and diagonal shading scenarios. The comparative performance study of PV configurations is analyzed in terms of their mismatching power loss, fill factors, efficiency, global maximum power points (GMPPs), local maximum power points (LMPPs), voltages and currents at GMPPs, open-circuit voltage, and short-circuit current. KYOCERA-KC200GT PV module parameters are considered for simulating all PV configurations.

Анализ режимов и выбор параметров преобразователя напряжения и контроллера максимальной мощности автономной фотоэлектрической станции

Анализ режимов и выбор параметров преобразователя напряжения и контроллера максимальной мощности автономной фотоэлектрической станции

Optimized TSMC Control Based MPPT for PV System under Variable Atmospheric Conditions Using PSO Algorithm

Abstract In the present paper, we report a robust and efficient terminal sliding mode controller based particle swarm optimization (PSOTSMC) for maximum power point tracking (MPPT) of photovoltaic (PV) system under variable atmospheric conditions. The PSO-TSMC controller combines the features of both terminal sliding mode control (TSMC) and particle swarm optimization (PSO) method. The proposed approach is designed based TSMC controller as robust nonlinear controller in order to make the PV system performs at the desired reference maximum power voltage (MPV) despite the atmospheric conditions variation, by regulating the control duty cycle. Moreover, the proposed approach applied TSMC controller with their optimal parameter by using PSO method. Furthermore, a comparative study, including the proposed PSO-TSMC controller, the standard TSMC and the conventional sliding mode control (SMC), is investigated under variable atmospheric conditions. Hence, simulation results reveal that the proposed approach assures more robustness against atmospheric conditions variation with best tracking performance and fast tracking response convergence in finite time compared to the other controllers (i.e. TSMC and SMC).

Optimal PV array configuration for extracting maximum power under partial shading conditions by mitigating mismatching power loss

The grid-connected or standalone PV central inverter architecture comprises of several PV modules which are connected in different ways to form the PV array. The power generation capability of the PV array is mainly affected by partial shading conditions (PSC). Due to PSCs, the power output of the PV array reduces dramatically, and mismatching losses are induced in the PV modules. To the extent of these problems, the multiple peaks are also appeared in the power-voltage (P-V) curve, which is very complicated to track the global maximum power point (GMPP). The main objective of this research paper is to model and simulate the Series (S), Series-Parallel (SP), Bridge-Link (BL), Honey-Comb (Hc), Total-Cross-Tied (TCt) and proposed Triple-Tied (TT) solar PV array configurations under various partial shading scenarios. The performance of all PV configurations is evaluated under uniform and eight different shading scenarios. The performance of the considered PV configurations is analyzed in terms of their mismatching power losses, fill factors, efficiency, global maximum power points (GMPPs), local maximum power points (LMPPs), voltages and currents at GMPPs, open circuit voltage and short circuit current. The above-mentioned PV configurations are modelled and simulated in Matlab/Simulink environment by considering KC-200GT module parameters.

Power Electronic Converter Configurations Integration with Hybrid Energy Sources – A Comprehensive Review for State-of the-Art in Research

The electricity demand is increasing day by day. On the other side, fossil fuels are depleting at a higher rate. The abundantly available renewable energy sources like solar, wind, and fuel cells are becoming popular sources of energy. But due to the intermittent availability of these renewable energy sources, two or more energy sources are integrated together. Power electronic converters are used for integrating different energy sources. Various power electronic converter (PEC) topologies have been proposed and analyzed in detail to control maximum power point, voltage, frequency, and harmonic distortions. Each of these configurations will differ in its topology and operating principle. The objective of this paper is to present a comprehensive review of various aspects of PEC configurations available for integration of renewable energy sources by systematization into three groups (AC shunt coupled, DC shunt coupled, and hybrid coupled systems). Emphasis is also given to coordination power control, maximum power point, and grid integration challenges related to the hybrid energy system. Furthermore, a general, system modeling of solar, wind, and grid integration is presented here to give an overall picture of a hybrid renewable energy system.

Investigating the performance of constructed wetland microbial fuel cells using three indigenous South African wetland plants

Constructed wetland microbial fuel cells (CW-MFC) can be used to treat wastewater while also generating bio-electricity. Most research on CW-MFCs have focused on cell configuration rather than the influence different wetland plants have on bio-electricity production.In this study, three different indigenous wetland plants were investigated: Cyperus prolifer, Wachendorfia thyrsiflora, and Phragmites australis. Bio-electricity production was assessed in terms of maximum power density and voltage variation. The highest power density and voltage was obtained from the C. prolifer plant species (229 ± 52 mW/m3; 510 mV). The removal efficiency of chemical oxygen demand was 97 ± 1% for C. prolifer, which was higher than W. thyrsiflora (94 ± 1%), P. australis (94 ± 1%) and the control (unplanted) system (90 ± 2%). Phosphorus removal was measured in terms of orthophosphate removal efficiency. The C. prolifer plant species achieved higher orthophosphate removal efficiency (98 ± 0%) than the control (72 ± 7%), W. thyrsiflora (58 ± 6%) and P. australis (81 ± 4%). It was determined that a high root specific area and biomass were advantageous to power production. It was also found that rapid acclimatisation to the wastewater was an important factor for generating power.From this study, it was determined that C. prolifer was the most suitable wetland plant in terms of bio-electricity, organic matter, ammonia and phosphate removal among the investigated plant species. Hence, in the design of a CW-MFC it would be advisable to use C. prolifer to simultaneously treat wastewater and produce bio-electricity.

Wireless Sliding MPPT Control of Photovoltaic Systems in Distributed Generation Systems

The aim of a photovoltaic (PV) system’s control is the extraction of the maximum power even if the irradiance, the temperature, or the parameters vary. To do that, a maximum power point tracking (MPPT) algorithm is required. In this work, a sliding control is designed to regulate the PV modules’ output voltage and make the panel work at the maximum power voltage. This control is selected to improve the robustness, the transient dynamic response, and the time response of the system under changeable environmental conditions, adjusting the duty cycle of the DC/DC converter. The DC/DC converter connected to the PV module output is a buck-boost converter. This configuration presents the advantage of providing voltages lower or higher than supplied by the photovoltaic modules to provide the required voltage to the load (including the voltages ceded by telecommunication loads, amongst others). In addition, a remote sliding control is developed to make the global supervision of the PV system in distributed generation grids. The designed algorithm is tested in an experimental platform, both locally and remotely connected to the base station, to prove the effectiveness of the sliding control. Thus, the communication effect in the control is also analyzed.

Real-Time Simulation of Smart DC Microgrid with Decentralized Control System Under Source Disturbances

Decentralized control of DC microgrid (dcµG) using hybrid renewable energy sources (RES) and battery energy storage system (BESS) which operate with and without grid-connected mode is proposed in this paper. In dcµG integrated with multiple RES and BESS, fluctuating output characteristics of the distributed generations (DGs) due to changing input conditions and the dynamic interactions of the source and load interface converters are main factors which cause stability problem of DC bus voltage. Thus, to solve this problem, the decentralized control scheme which uses bus voltage level as communication link in the control law is proposed in this paper. Accordingly, the control method realizes different operating modes based on the available generations and load demand. Maximum power and constant voltage controls schemes are applied in the DGs interfacing control to regulate the power and voltage variations due to changing input conditions. Furthermore, in the control strategy, the source and battery interfacing converters are controlled autonomously using the bus voltage level without any communication. This maintains the reliability and flexibility of the system. The proposed system model is developed with Matlab/Simulink SimPowerSystem and simulated with real-time simulation using OPAL-RT.

Metode Penggabungan Daya Secara Adaptif Untuk Power Supply Hibrida

Public services require computer-based electricity supply. Not continuous electricity supply in some areas led to a power supply from an alternative power source becomes indispensable. One alternative power source is a solar cell. Solar cell is a sustainable source of electricity but power output is not constant depending on the sunlight. The power source is needed to anticipate the lack of power when the power generated by the solar cell is not enough.In this paper proposed a hybrid design that combines the power supply of electricity from the solar cell, the network provider of electricity, and batteries. This paper discusses methods of hybrid electric power from three sources. Hybrid power is usually done by PCC (Power Controlled Converter), which consists of a controlled power converter for each channel input, but in this study the method proposed hybrid power input specification in the form of a synchronization circuit PCC then replaced by a diode circuit.The design of hybrid power supply in this study resulted in the specification input from the solar cell with Vmp channels (maximum power voltage) 35VDC Voc (open circuit voltage) 43.78VDC, channels of electricity provider with the already converted with SMPS (Switched Mode Power Supply) to 35VDC, and channels of a battery with a minimum voltage of 21VDC maximum 27.6VDC. The test results showed that the implementation of the proposed hybrid method can perform a single capture or hybrid power, and can transfer power between the source retrieval without pause. Implementation of the proposed hybrid method has a 21VDC output voltage range - 43.78VDC and efficiency of 98.6% - 99.5%.

Concentrating System’s Design and Performance Analysis for Spacial Solar Array

A large area of sunlight onto solar cells is gathered by concentrating system for spacial concentrating solar array, which reduces the amount of solar cells by increasing light intensity onto the solar cells of the unit area. Under concentrating conditions, the short-circuit current, open-circuit voltage, fill factor, efficiency, operating temperature and strong thermal-electrical coupling characteristics of concentrating solar cells are different from the conventional solar cells because of the high intensity and high operating temperature. The concentrating module design, solar cell selection, and design of solar cell heat-dissipation have been carried out. The thermal-electric coupling model of special concentrating photovoltaic system has been established. The relationships among concentrated ratio, substrate-thickness, thermal conductivity of substrate-material and solar cell’s temperature, density of short-circuit current, open-circuit voltage, maximum output power have been analyzed, which provide a view to a reasonabl0e match and selection of multi-parameters in engineering design. Results show that the concentrated ratio has an overall effect on the open-circuit voltage, short-circuit current, efficiency and operating temperature of the solar cell. There is a strong coupling relationship among the parameters, and the positive and negative impacts caused by the concentrating characteristics should be weighed in the engineering design. The short-circuit current density of concentrating solar cells is proportional to the concentrated ratio. Under the lower concentrated ratio circumstance, fill factor and efficiency is not substantially affected by the concentrated ratio. The maximum output power and open-circuit voltage increase with the increase of concentrated ratio. Temperature of concentrating solar cells has an adverse effect on the open-circuit voltage, efficiency and output power, which needs high efficient radiator measures to be taken. The operating temperature of solar cells could be decreased significantly by the high thermal conductivity of the substrate-material. The concentrated ratio between 9~15 is recommended for spacial solar array, which not only embodies the advantage of concentrator like improving the cell-efficiency and decreasing the cost, but also doesn’t exact the deploying precision of concentrating system.

Offline Photovoltaic Maximum Power Point Tracking

As more renewable energy sources are connected to the electrical grid, it has become important that these sources participate in providing system support. It has become needful for grid-connected solar photovoltaics to participate in support functions like frequency support. However, photovoltaic systems need to implement a maximum power tracking algorithm to operate at maximum power and a method for de-loading photovoltaic systems is necessary for participation in frequency support. Some conventional maximum power tracking techniques are implemented in real time and will not adjust their output fast enough to provide system support while other may respond fast but are not very efficient in tracking the maximum power point of a photovoltaic system. This paper presents an offline method to estimate the maximum power voltage and current based on the characteristics of the photovoltaics module available in the datasheet and using the estimated values to operate the photovoltaics at maximum power. The performance of this technique is compared to the conventional technique. This paper also describes how the photovoltaic system can be de-loaded.

Hysteresis-free perovskite solar cells made of potassium-doped organometal halide perovskite

Potassium-doped organometal halide perovskite solar cells (PSCs) of more than 20% power conversion efficiency (PCE) without I-V hysteresis were constructed. The crystal lattice of the organometal halide perovskite was expanded with increasing of the potassium ratio, where both absorption and photoluminescence spectra shifted to the longer wavelength, suggesting that the optical band gap decreased. In the case of the perovskite with the 5% K+, the conduction band minimum (CBM) became similar to the CBM level of the TiO2-Li. In this situation, the electron transfer barrier at the interface between TiO2-Li and the perovskite was minimised. In fact, the transient current rise at the maximum power voltages of PSCs with 5% K+ was faster than that without K+. It is concluded that stagnation-less carrier transportation could minimise the I-V hysteresis of PSCs.

The Improvement of Solar Cell Output Power Using Cooling and Reflection from Mirror

This paper explains the experimental investigation to improve the output power of solar cell using cooling and light reflection from mirrors. The results show that by adding mirror, the current and output power of solar cell increase but the open circuit voltage and maximum power voltage decrease due to heat. By adding cooling, the open circuit voltage and the maximum power voltage are improved, so the output power also increases.

ANALYSIS ON SOLAR PANEL PERFORMANCE AND PV-INVERTER CONFIGURATION FOR TROPICAL REGION

In this paper, proper inverter topology for tropical region will be determined with temperature effect as a considered factor. PV characteristics on certain temperature are obtained through mathematical equations in MATLAB-Simulink and it will be represented by PV I-V and P-V characteristic curves. Based on the modeling, some PV parameters such as temperature coefficients of short circuit current (ISC), open circuit voltage (VOC), maximum output power (PMAX), and maximum power voltage (VMP) can be determined as high as 0.56%/oC, -0.31%/oC -0.4%/oC, and 0.43 %/oC respectively. As the result, for tropical region, the central inverter is the most proper inverter topology to supply 5 kWAC PV system, string inverter in the 2nd place, and AC module with utility rates of 97.34%, 96.32 %, and 88.1% based on direct measurement on PV panel’s temperature respectively. From NOCT approach, the utility rates are around 92.96 % for central inverter, 91.98% for string inverter and 91.8 % for AC module.