Voltage Short Circuit Research Articles

Evaluation of Model for External Short Circuit Voltage Behavior Prediction of Lithium-ion Batteries

Evaluation of Model for External Short Circuit Voltage Behavior Prediction of Lithium-ion Batteries

분산전원의 고장 전류와 고장 전압 대한 영향 연구: 증명과 사례 제시

Distributed generation (DG) resources defined as small, medium, or large grid-connected or stand-alone electric energy sources can show many advantages such as improving reliability (e.g., decreasing the failure frequency and duration), the emergency supply of power (e.g., islanding operation), or peak power reductions (e.g., peak demand reduction at peak hours). However, these DG resources are in nature an electric energy source, so they can affect the short-circuit current of the system to which they are connected. Thus, the objective of this study is to present several case studies on the effect of DG on a change in short-circuit current and voltage. For this purpose, Part 1 presented a method of accurately calculating short-circuit current caused by DG working as a current source, which was defined as the current injection method. As an extended study, Part 2 of this study presents an example of calculating short-circuit current and voltage in detail. As a result of case studies, this study verifies the proposed method and examines the effect of DG on short-circuit current and voltage after a single line-to-ground fault. The case studies show that as the capacity of DG increases, DG can also increase the short-circuit current, but with a slight change rate (e.g., up to 17.44% in the simple 5-bus power system), and DG may cause a slight overvoltage problem during or after the fault.

Analytical Model of InP QWs for Efficiency Improvement in GaInP/Si Dual Junction Solar Cell

Quantum wells (QWs) are proven to enhance the short circuit current and voltage preservation measures help in efficiency enhancement with little degradation of open circuit voltage . Herein, an integrated GaInP/Si dual junction solar cell is proposed by incorporating the QWs in the top cell and carrier‐selective passivated contact at the bottom cell of the design. The QW increases the photon absorption of sub‐bandgap energies, buffer layer reduces the misfits between the lattice mismatched layers, and passivation mechanism improves the overall efficiency. Increasing the number of QWs increases the depletion width of QW region. This reduces the carrier lifetime () and increases the recombinations in the QW region. It results in the reduction in passivation quality and, therefore, reduces the open circuit voltage (). QW strain balancing and measures to reduce the threading dislocations has been considered. Also, the wide bandgap GaInP tunnel junction along with highly doped GaAs tunnel junction has been analyzed to observe the parasitic effect. The GaInP/Si‐integrated model achieves efficiency of 33.39% when the QWs are incorporated in the top cell. The effect of wide bandgap tunnel junction is also evaluated using GaInP tunnel junction.

Fabrication of bimetallic inlaid working electrode for highly efficient dye sensitized solar cells

Gold nanoparticles (AuNPs) including Au-Pink, Au-Orange, Au-Purple, Au-Blue were synthesized using chemical reduction method, their optical and morphological properties were characterized and they were used in PV devices. The active layer of dye-sensitized solar cells having titanium dioxide (TiO2) solid microsphere (MS) made up of nanoparticles granules were coated with AuNPs. This Au-TiO2 MS hybrid DSSC boosted light harvesting, charge separation, and improved the charge transportresulting in an improvement of both short circuit current and open circuit voltage. The power conversion was boosted 16% compared to the control photoanode of TiO2 solid microsphere. Further enhancement in the short circuit current was observed during the incorporation of both Au and Ag, bi-metallic nanoparticles in the TiO2 matrix. An overall photo to electron conversion efficiency of 8.73% was obtained due to the plasmonic cooperation effect of TiO2-Ag-Au hybrid structures, which is 65% increase over pure TiO2 DSSCs. The local electrified intensity enhancement around the individual Ag, Au nanoparticles and plasmonic coupling of the Ag-Au combination have been used to explain these results with finite-difference time-domain simulation.

Comparison of development prospects between silicon solar cells and perovskite solar cells

The development history, preparation process, structure and working principle of silicon solar cells and perovskite solar cells are introduced. The main parameters and production processes of the two kinds of solar cells are compared. The advantages and disadvantages of perovskite solar energy compared with existing solar cells in market application are analyzed and summarized, including good light absorption, high energy conversion efficiency and simple process flow, The problems of cost, size and stability of perovskite solar cells in market application are pointed out and the solutions are given. Perovskite solar cells have an excellent development prospect. Short circuit voltage, open circuit current and efficiency exceed those of silicon solar cells and are expected to gradually replace silicon solar cells in the market.

Energy level tuning of push-pull porphyrin sensitizer by trifluoromethyl group for dye-sensitized solar cells

We have introduced trifluoromethyl groups into meta-positions of two meso-phenyl rings of a push-pull-type porphyrin dye (ZnP-CF[Formula: see text] to modulate the energy levels of the porphyrin dye for dye-sensitized solar cells (DSSCs). The light-harvesting ability of ZnP-CF[Formula: see text] is almost comparable to those of reference porphyrins where the trifluoromethyl groups are replaced with methyl (ZnP-CH[Formula: see text] or tert-butyl groups (YD2). We revealed that the introduction of the electron-withdrawing trifluoromethyl groups is effective to lower the excited-state oxidation potential of the porphyrin (–0.80 V vs NHE), which is consistent with the theoretical calculation. Meanwhile, DSSCs with ZnP-CF[Formula: see text] exhibited a lower power conversion efficiency ([Formula: see text] of 5.95% than DSSCs with ZnP-CH[Formula: see text] ([Formula: see text] = 7.33%) and YD2 ([Formula: see text] = 8.97%) because of the severe aggregation tendency of ZnP-CF[Formula: see text] arising from the trifluoromethyl groups. In addition, the insufficient steric bulkiness of the trifluoromethyl and methyl groups relative to tert-butyl groups would result in the lower short circuit current and open circuit voltage for ZnP-CF[Formula: see text] and ZnP-CH[Formula: see text] due to fast charge recombination between electrons in the conduction band of TiO2 and I[Formula: see text]in the electrolyte solution. Overall, introducing both trifluoromethyl groups and bulky substituents into a porphyrin core would be necessary to boost cell performance.

Analyses of Pore-Size-Dependent Ionic Transport in Nanopores in the Presence of Concentration and Temperature Gradients.

Mass transport through nanopores occurs in various natural systems, including the human body. For example, ion transport across nerve cell membranes plays a significant role in neural signal transmission, which can be significantly affected by the electrolyte and temperature conditions. To better understand and control the underlying nanoscopic transport, it is necessary to develop multiphysical transport models as well as validate them using enhanced experimental methods for facile nanopore fabrication and precise nanoscale transport characterization. Here, we report a nanopore-integrated microfluidic platform to characterize ion transport in the presence of electrolyte and temperature gradients; we employ our previous self-assembled particle membrane (SAPM)-integrated microfluidic platform to produce various nanopores with different pore sizes. Subsequently, we quantify pore-size-dependent ionic transport by measuring the short circuit current (SCC) and open circuit voltage (OCV) across various nanopores by manipulating the electrolyte and temperature gradients. We establish three simple theoretical models that heavily depend on pore size, electrolyte concentration, and temperature and subsequently validate them with the experimental results. Finally, we anticipate that the results of this study would help clarify ion transport phenomena at low-temperature conditions, not only providing a fundamental understanding but also enabling practical applications of cryo-anesthesia in the near future.

Morphological evolution of sol-electrophoretic deposited ZnO nanostructures on anodic TiO2 nanotubes for back-side illuminated dye-sensitised solar cells

Efficient photoanodes are essential for dye-sensitized solar cells (DSSCs). We report on sol-electrophoretic deposition of ZnO/TiO2 heterojunction structures with enhanced photocurrent-photovoltage performance for back-side illumination DSSCs. An anodic oxidation method was used for the preparation of TiO2 nanotube arrays (TNAs). ZnO nanostructures with different morphologies were successfully deposited on TNAs via sol-electrophoretic process. The results revealed that TNAs decorated with ZnO favors the photovoltaic properties reaching the best photoanode performance in a pH and temperature of 8.5 and 30°C, respectively, under an electrophoretic deposition (EPD) potential of 10 V. This photoanode generates short circuit current (Jsc) and open circuit voltage (Voc) of 3.28 mA/cm2 and 0.79 V, respectively. Consequently, the power conversion efficiency (PCE) acquired 1.525% with a fill factor of 72% for the best ZnO/TiO2 heterojunction enhances the DSSC performance by 107% with respect to similar TNAs due to the surface passivation of electronic states eliminating the recombination rate.

Study on the performance of open-circuit failure gas discharge tube under the context of DC short-circuit

Protective devices are used at every single port of electrical equipment, such as gas discharge tube(GDT), metal oxide varistors(MOV), and transient voltage suppressors diodes(TVS). These devices are capable to absorb lightning, surge, static electricity and other burst waves by directly spanning across both ends of the circuit or grounding mode. When the protective devices overabsorb these burst waves, short-circuit failure will result. The short-circuit failure of protective devices is one of the potential hazards that would cause combustion. In order to avoid the fault combustion of GDT caused by short-circuit, an open-circuit failure gas discharge tube (OGDT) with the capacity of open-circuit failure is proposed by improving the existing GDT with a high and low temperature sealing solder. This paper focuses on exploring the structure and working mechanism of OGDT, with the open-circuit failure response arc extinguishing time of the OGDT measured by coupling the DC power supply with an 8/20 μs impact current generator. The impact of short-circuit current and DC voltage on OGDT response arc extinguishing time is analyzed by conducting experiments and the effect of OGDT is verified by adjusting the area of low temperature weld. The results show that with the rise of short-circuits current, the open-circuit response arc extinguishing time of OGDT first decreases and then increases. A larger area of the low-temperature welding solder leads to a shorter the response arc extinguishing time. Besides, the higher the applied DC voltage, the shorter the response arc extinguishing time. When the short-circuit current reaches 10 A, the optimal response arc extinguishing time is 300 ms. When the short-circuit current falls below 25 A, the response arc extinguishing time of OGDT can reach a lower level than 1000 ms. The OGDT open-circuit failure action screen is captured by a high-speed camera to verify its outcome. The high-speed camera captures the OGDT open-circuit failure and excision failure at 300 ms, which is consistent with the experimental waveform results. The research results provide practical guidance on the selection of OGDT.

Single-step, catalyst-free, and green synthesis of graphene transparent electrode for organic photovoltaics

Graphene is a promising transparent conducting electrode (TCE) for organic photovoltaics (OPVs) due to its outstanding optical and electrical properties. However, the high cost and complexity of graphene synthesis on transparent substrates as well as the use of hazardous carbon sources limits the large-scale application of graphene TCEs. This work reports a single-step synthesis of graphene TCEs on glass substrates for OPVs from plant extract by Radio frequency plasma enhanced chemical vapor deposition. This approach provides fast, cheap, and catalyst-free production of graphene from a sustainable and environmentally-friendly carbon resource.The as-prepared graphene films reveal high quality structure with promising optical and electrical properties. Inverted OPV devices built on the as-synthesized graphene TCEs exhibit 80% of the power conversion efficiency of their indium tin oxide counterparts, and higher short circuit current density and open circuit voltage.

Simplified Inverter-Based Generation Model for Protection and Short-Term Stability Studies in Electromagnetic Transient Resolution

The new dynamics of inverter-based generation (IBG) and the lack of accurate models jeopardize the safety of power systems. Additionally, most of the detailed models for electromagnetic transients (EMT) from manufacturers are black boxes. For this reason, the objective of this work was to propose a generic IBG model in EMT resolution suitable for short-circuit, protections, and short-term voltage stability studies. For this purpose, the model considered different functionalities, such as synchronization in case of unbalanced voltage sags, flexible negative sequence current injection, peak current limitation, dynamic reactive power control, and fault ride-through (FRT). This model allowed grid operators to meet the challenge of performing accurate simulations with high integration of renewable resources in their energy matrix. The model was also based on a voltage-controlled current source in the ATP/EMTP software. The short-circuit response was evaluated in a simulation scenario for different fault events presenting a reliable behavior due to the consideration of technical and regulatory requirements and constraints of IBGs. Finally, the proposed model has a fast initialization and is suitable for simulations with large time steps, making it valuable for EMT simulations in large grids.

Thickness dependent wavelength selective NIR-UV-visible photoresponse in ZnO nanowires and silicon heterojunction

In this paper, we report ZnO nanowires (NWs) and silicon-based type-II PN heterojunction for UV–Visible–Infrared self-powered photodetection. The as-grown ZnO NWs were highly crystalline and aligned along the c-axis in the [002] direction revealed in the HRTEM and XRD measurements. The Hall measurements revealed the n-type behavior for ZnO and p-type for p-Si with carrier concentrations of 4.09 × 1016 cm−3 and 1.38 × 1017 cm−3, respectively. The depletion widths were estimated to be ∼35 nm and ∼120 nm, respectively for p-Si and n-ZnO NWs. The Ag/n-ZnO NWs/p-Si/Ag PN heterojunction showed large photoresponse, even at zero bias, under the illumination of commercially available UV–Visible–NIR LEDs, thus acting as a self-powered photodetector. It was interesting to observe that the photoresponse was dependent on the growth time and hence the thickness of ZnO NWs thin film. A maximum zero bias responsivity of ∼0.1 A/W at green (515 nm) was observed and was large for the junction with thicker ZnO NWs film (5 h growth), compared with thinner (3 h growth) device under IR (950 nm) LED illumination, however, it was observed otherwise for UV (395 nm) LED. This suggests that tuning the thickness of the ZnO NWs thin film results in the wavelength selective photoresponse, consequently, paving the way towards UV blind IR-visible photodetector based on ZnO NWs. The transient short circuit current (Isc vs t) and open circuit voltage (Voc vs t) properties showed fast and large responses under periodic illumination of all LEDs (UV–Vis–NIR). The response was observed to depend on the intensity of light and the maximum Voc comes out to be ∼102 mV and Isc ∼5.58 μA, under the illumination of a red laser diode.

Effects of Damp-heat on Shunt, Series Resistances and Fill Factor into Crystalline Silicon Photovoltaic Solar Modules in Tropical Zone

Most solar module manufacturers guarantee the minimum performance of their modules for 20 to 25 years. But some time after their installation, one observes faults which appear on the various components of these modules. During long-term exposure to severe climatic conditions, these faults, which accumulate over time, lead to performance losses of the module. This performance degradation is due to several factors such as humidity, temperature, heat, irradiation etc. These factors cause various degradation processes which can be electrical, chemical, mechanical, thermal, etc. The tropical zone, the middle of our study being characterized by high heat and humidity, has definite impacts on the electrical parameters of photovoltaic modules. The electrical parameters degradation is among others cause of photovoltaic modules performance loss. This study purpose is to study the degradation of the shunt resistance, the series resistance and the form factor of photovoltaic modules installed in tropical areas in order to appreciate their impact on the performance loss of the latter. For that, we used Peck performance degradation analytical model and Braisaz degradation analytical models of shunt resistance and the series resistance to calculate over a period of forty years, in real conditions in the tropical environment, the degradation of these electrical parameters of the photovoltaic module. The results obtained are compared to those obtained during the Hulkoff experimental tests in the state of Miami in Florida in 2009. The degradation rates obtained in the six cities concerned by the study vary between 17.33-35.67% for resistance shunt, between 3.77-7.55% for the series resistance and between 8-19% for the fill factor. In addition, these electrical parameters degradation rates obtained experimentally by Hulkoff and taken up by [1], are respectively 35.14% for the shunt resistor, 9.43% for the series resistor and 3.03% for the fill factor over the study period.
 So, future researches on crystalline silicon photovoltaic solar module can be effect of Damp-Heat on short circuit current and open circuit voltage in tropical area.

Short and Open Circuit Fault Detection in On-Grid Photovoltaic Systems 1MWP Bangli Based on Current and Voltage Observation

Photovoltaic (PV) systems as clean and green electrical energy generators have increased sharply in the last 10 years. The installation of a PV system in an open area is one of the causes of frequent faults/damage to the PV system. Fault in the PV system causes a decrease in efficiency, weak reliability, and disruption of the continuity of the electrical power distribution, which in turn causes the low performance of the system. This research does on the on-grid PV system 1MWp Bangli which consists of 278 PV arrays and 5004 monocrystalline solar modules 200Wp, which started operation in 2013. This research aims to find open circuit and short circuit faults that occur in the PV system Bangli. The method used in this research is the current and voltage observation method. Current and output voltage measurements from the PV array are carried out as well as measurements of working module temperature and solar irradiance. To calculate the output PV array's current (RI) and voltage (RV) indicators; Calculation of the current (RIM) and voltage (RVM) indicators under fault-free conditions, and the short circuit (TIO) and open voltage (TVS) threshold are calculated. As a result, this study succeeded in determining short and open circuit faults that occur in PV systems on grid 1MWp Bangli.

Development of an Empirical Coefficient for the Short Circuit Current to Determine Soiling Effect on PV Performance

In this study, the effect of dust accumulation on the performance of photovoltaic (PV) module has been shown. A statistical analysis has been conducted on a medium sized sample data collected from 30 hours of experimental work to obtain an empirical coefficient like temperature coefficients of short circuit current and open circuit voltage usually provided by manufacturers. This coefficient will be named dust coefficient of short circuit current and it will represent a predefined range of environmental conditions and soiling amounts; as the available testing conditions, and the statistical model prediction limits bound the coefficient extent of applicability.

Implementation and Validation of Maximum Power Point Tracking (MPPT) of the Photovoltaic System on Arduino Microcontroller

In this research paper, we introduce real-time implementation, using Matlab and Simulink environments. The purpose is to study our proposed system, consisting of a photovoltaic, boost converter, and Arduino mega board. The latter communicates with the physical environment from the current and voltage sensors and executes the proposed MPPT commands (perturb-and-observe, short circuit current, incremental conductance, and open circuit voltage), varying the duty cycle of the signal PWM (Pulse Width Modulation) static converter.

Energy harvesting from charged conical nanopore with salinity and temperature gradient

• An energy harvesting system from charged conical nanopore with coupled salinity and temperature gradient is proposed. • An interesting completive mechanism between the concentration gradient and temperature gradient effect was found, which determined the output performance. • The enhancement of negative temperature difference on output power is more significant compared with positive temperature difference. • The research results provide useful information for the design and optimization of energy devices. Renewable energy has been received more attention with the increasingly serious energy crisis. In this paper, an energy harvesting system from charged conical nanopore with coupled salinity and temperature gradient is proposed. The results show that the obtained maximum power increases first and then decreases as the concentration difference increases. Particularly, the enhancement of negative temperature difference (NTD) on maximum output power and the corresponding energy conversion efficiency is more significant compared with positive temperature difference (PTD) due to the simultaneous increase of short circuit current and open circuit voltage. Besides, the maximum output power is larger when the low concentration reservoir is connected to the tip end of the conical nanopore. The obtained maximum optimal value is about 0.22 pW. In the further investigation of a temperature gradient, we found that the short circuit current, open circuit voltage, and maximum output power show the approximately linear thermal response characteristics as the temperature difference is increased. Besides, an interesting competive mechanism between the concentration gradient effect and temperature gradient effect is found, which determines the prior conical nanopore orientation. The related research results provide useful information for the design and optimization of energy devices.

Optimizing the size and amount of CdS quantum dots for efficiency enhancement in CdS/N719 co-sensitized solar cells

Co-sensitization of TiO 2 photoanodes in solar cells with Ruthenium dye and quantum dots offer better photovoltaic performance compared to the sensitization by the dye only. In the present study, TiO 2 nanostructured photoanode was co-sensitized with CdS quantum dots and N719 dye. CdS quantum dots were deposited using successive ionic layer adsorption and reaction (SILAR). A suitable thin ZnS interfacial layer has been introduced between two sensitizers to prevent the corrosion of CdS quantum dots by the iodide-based liquid electrolyte. In order to get the highest efficiency, the number of SILAR cycles for CdS quantum dot deposition has been optimized. A power conversion efficiency of 6.79% with short-circuit current density of 15.55 mA cm −2 and open circuit voltage of 764.5 mV have been obtained for the co-sensitized solar cell made with TiO 2 /CdS/ZnS/N719 co-sensitized photoanode under the illumination of 100 mW cm −2 with AM 1.5 spectral filter. Efficiency and short-circuit current density of the solar cell have been enhanced by 11.31% and 6.58% respectively due to the co-sensitization. The optimized co-sensitized solar cell shows a higher incident photon to current conversion efficiency and a reduced electron recombination compared to the solar cell with dye-sensitized photoanode. Higher recombination resistance and longer electron lifetime of the solar cell with CdS/ZnS/N719 co-sensitized TiO 2 photoanode have contributed to the increased short circuit current and open circuit voltage leading to the enhanced efficiency of 6.79% which is among the highest for a co-sensitized dye sensitized solar cell . • TiO 2 photoanode was co-sensitized with CdS quantum dots and N719 dye. • ZnS layer was introduced between CdS and N719 to prevent the corrosion of CdS. • Number of CdS SILAR cycles was optimized to get the highest solar cell efficiency. • Solar cell efficiency of 6.79% was obtained for TiO 2 /CdS/ZnS/N719 photoanode. • New photoanode showed a high recombination resistance and long electron lifetime. • 6.79% is among the highest efficiencies reported for co-sensitized solar cells.

Simple organic dyes containing multiple anchors as effective co‐sensitizers for DSSCs loaded with Ru (II) complex N‐719

In this work, we report a comprehensive photovoltaic investigation of eight pure organics, structurally simple, and low‐cost 2‐cyano‐N‐thiazolyacrylamide dyes (AM‐1‐8) co‐sensitizers for dye‐sensitized solar cells (DSSCs) with the standard Ru (II) dye (N‐719). A co‐sensitization strategy has been applied for enhancing the performance of DSSCs wherein a Ru (II) metal complex is combined with a simple type of the designed organic metal‐free dyes (AM‐1‐8). The co‐sensitization by the absorption of co‐sensitizers AM‐1‐8 leads to a broader light‐harvesting ability (300–750 nm) and scored photovoltaic efficiency at a range of 6.08%–9.30%. Upon co‐sensitization, the device made of bis(2‐cyanoacetamide) co‐sensitizer AM‐7 system yielded the highest power conversion efficiency (PCE) = 9.30% with JSC = 20.96 mA/cm2, VOC = 0.73 eV, and FF = 60.78 that outperformed the standard dye (N‐719). N‐719 dye only showed PCE of 7.30% with JSC = 18.68 mA/cm2, VOC = 0.64 eV, and FF = 61%. The great enhancement of the effect of the co‐sensitizer AM‐7 on the N‐719 can be related to the enhancement of both short current density (JSC) and open circuit voltage (VOC). The greater JSC value can be attributed to the maximum dye loading value of this dye on the TiO2 surface (3.76 × 10−5/mol cm−2) as a result of the presence of bis‐anchoring function within the dye molecule. The increase in the VOC value can be attributed to its highest recombination resistance because of the multi‐anchoring groups, which was confirmed by electrochemical impedance spectroscopy (EIS). Theoretical density functional theory (DFT) and highest occupied molecular orbital (HOMO)‐ lowest unoccupied molecular orbital (LUMO) energy were performed to study the electron density distribution between donor and acceptor moieties. All the multi‐anchoring functions presented in bis(2‐cyanoacetamide) and 2‐cyanacrylamide co‐sensitizers demonstrate promising co‐sensitizers for excellent photovoltaic performance response on the standard dye (N‐719).

Flexible polymer-based triboelectric nanogenerator using Poly(vinylidene fluoride) and bombyx mori silk

This paper demonstrates a flexible triboelectric nanogenerator (TENG) using Poly(vinylidene fluoride) (PVDF) and silk by exploiting their inherent susceptibility for gaining and losing electrons. Bombyx mori silk possesses a strong capability of losing electrons whereas PVDF has the penchant for gaining electrons. Hence the combination of silk and PVDF could be explored as a novel and unique triboelectric pair for the fabrication of triboelectric nanogenerator. With this motivation, silk-PVDF-based TENG was fabricated on flexible substrate along with the systematic evaluation of its output performance. The primary objective of this paper is divided into two major parts. Initially, a comprehensive study was carried out to investigate the maximum output voltage of the TENG and its correlation with the morphology and composition of PVDF films. The structural optimization of the TENG was also performed in order to deduce the maximum output. Finally, various practical applications of silk-PVDF-based TENG were demonstrated. Through proper optimization, the maximum short circuit current and open circuit voltage acquired from the TENG was experimentally found out to be 11.3 μA and 611 V (peak to peak value), respectively. A relatively high output power density of 1.85 W/m2 was obtained from the optimized nanogenerator for a load resistance of 10 MΩ. The efficacy of this prototype was investigated by powering up commercial red LEDs, charging of capacitors, and harvesting energy from human body movement. The TENG is not only capable to light up 56 commercial red LED bulbs but also is able to harvest mechanical energy from body motion. The highest amount of energy was scavenged from human footsteps.