Kalman filter applied to Thevenin’s modeling of a lead-acid battery

<span>This article determines the internal parameters of a battery analyzed from its circuit equivalent, reviewing important information that can help to identify the battery’s state of charge (SOC) and its state of health (SOH). Although models that allow the dynamics of different types of batteries to be identified have been developed, few have defined the lead-acid battery model from the analysis of a filtered signal by applying a Kalman filter, particularly taking into account the measurement of noise not just at signal output but also at its input (this is a novelty raised from the experimental). This study proposes a model for lead-acid batteries using tools such as MATLAB^® and Simulink^®. First, a method of filtering the input and output signal is presented, and then a method for identifying parameters from 29 charge states is used for a lead-acid battery. Different SOCs are related to different values of open circuit voltage (OCV). Ultimately, improvements in model estimation are shown using a filter that considers system and sensor noise since the modeled and filtered signal is closer to the original signal than the unfiltered modeled signal.</span>

Parametric estimation in photovoltaic modules using the crow search algorithm

<p>The problem of parametric estimation in photovoltaic (PV) modules considering manufacturer information is addressed in this research from the perspective of combinatorial optimization. With the data sheet provided by the PV manufacturer, a non-linear non-convex optimization problem is formulated that contains information regarding maximum power, open-circuit, and short-circuit points. To estimate the three parameters of the PV model (i.e., the ideality diode factor (a) and the parallel and series resistances (R_p and R_s)), the crow search algorithm (CSA) is employed, which is a metaheuristic optimization technique inspired by the behavior of the crows searching food deposits. The CSA allows the exploration and exploitation of the solution space through a simple evolution rule derived from the classical PSO method. Numerical simulations reveal the effectiveness and robustness of the CSA to estimate these parameters with objective function values lower than 1 × 10⁻²⁸ and processing times less than 2 s. All the numerical simulations were developed in MATLAB 2020a and compared with the sine-cosine and vortex search algorithms recently reported in the literature.</p>

Methyl Orange-Doped Polypyrrole Promoting Growth of ZIF-8 on Cellulose Fiber with Tunable Tribopolarity for Triboelectric Nanogenerator

Cellulose fiber (CelF) is a biodegradable and renewable material with excellent performance but negligible triboelectric polarizability. Methods to enhance and rationally tune the triboelectric properties of CelF are needed to further its application for energy harvesting. In this work, methyl-orange-doped polypyrrole (MO-PPy) was in situ coated on CelF as a mediating layer to promote the growth of metal–organic framework ZIF-8 and to construct a cellulose-based triboelectric nanogenerator (TENG). The results showed that a small amount of MO-PPy generated in situ significantly promoted the growth of ZIF-8 on CelF, and the ZIF-8 deposition ratio was able to increase from 7.8% (ZIF-8/CelF) to 31.8% (ZIF-8/MO-PPy@CelF). ZIF-8/MO-PPy@CelF remained electrically conductive and became triboelectrically positive, and the triboelectricity’s positivity was improved with the increase in the ZIF-8 deposition ratio. The cellulose-based TENG constructed with ZIF-8/MO-PPy@CelF (31.8% ZIF-8 deposition ratio) and polytetrafluoroethylene (PTFE) could generate a transfer charge of 47.4 nC, open-circuit voltage of 129 V and short-circuit current of 6.8 μA—about 4 times higher than those of ZIF-8/CelF (7.8% ZIF-8 deposition ratio)—and had excellent cycling stability (open-circuit voltage remained almost constant after 10,000 cycles). MO-PPy not only greatly facilitated the growth of ZIF-8 on CelF, but also acted as an electrode active phase for TENG. The novel TENG based on ZIF-8/MO-PPy@CelF composite has cheerful prospects in many applications, such as self-powered supercapacitors, sensors and monitors, smart pianos, ping-pong tables, floor mats, etc.

Optimization of Electrical Performance of Defected n+-p-p+ Solar Cell with CdS/BaSi2/Cu2O Heterostructure Using SCAPs 1D

Present study investigates the performance of BaSi2 based BSF structure solar cell. SCAPS 1D simulator has been employed to investigate the heterostructure solar cell. To decrease the recombination loss due to minority carrier, a new configuration is proposed by inclusion of the p-type cuprous oxide (Cu2O) as BSF layer. The Cu2O BSF layer width varying in range 0.1 to 0.4 µm to analyze the feasibility of device for optimum performance. The anticipated structure consists of ZnO/CdS/BaSi2/Cu2O layers and offers the maximum efficiency of above 24%. Parameters for example open circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), conversion efficiency (η) and quantum efficiency (QE) of the device have been analyzed graphically. The optimized structure may have significant impact on future development of advanced photovoltaic devices.

Prussian Blue Analogue Derived Co3O4/CuO Nanoparticles as Effective Oxygen Reduction Reaction Catalyst for Magnesium-Air Battery

Developing efficient, durable, and cost-effective non-noble metal catalysts for oxygen reduction reaction (ORR) is necessary to promote the efficiency and performance of Mg-air batteries. Herein, the Co3O4/CuO nanoparticles were synthesized by a low-cost and simple approach using CuCo-based prussian blue analogue (PBA) as precursor of pyrolysis at different calcination temperatures. It was found that the Co3O4/CuO nanoparticles calcined at 600ºC (CCO-600) have relatively small size and superior ORR performance. The onset potential is 0.889 V and the diffusion limiting current density achieves 6.746 mA·cm-2, as well as prominent stability in 0.1 M KOH electrolyte. The electron transfer number of the CCO-600 is 3.89 under alkaline medium, which indicates that the reaction mechanism of ORR is dominated by 4 e process, similar to commercial Pt. The primary Mg-air battery with the CCO-600 as the cathode catalyst has been assembled and possesses better discharge performance than the CuCo-based PBA. The open circuit voltage of CCO-600 arrives at 1.76 V and energy density of 1895.95 mWh/g. This work provides an effective strategy to develop non-noble metal ORR catalyst for the application of metal-air batteries

Stretchable Printed Device for the Simultaneous Sensing of Temperature and Strain Validated in a Mouse Wound Healing Model

Temperature and strain are two vital parameters that play a significant role in wound diagnosis and healing. As periodic temperature measurements with a custom thermometer or strain measurements with conventional metallic gauges became less feasible for the modern competent health monitoring, individual temperature and strain measurement modalities incorporated into wearables and patches were developed. The proposed research in the article shows the development of a single sensor solution which can simultaneously measure both the above mentioned parameters. This work integrates a thermoelectric principle based temperature measurement approach into wearables, ensuring flexibility and bendability properties without affecting its thermo-generated voltage. The modified thermoelectric material helped to achieve stretchability of the sensor, thanks to its superior mechano-transduction properties. Moreover, the stretch-induced resistance changes become an additional marker for strain measurements so that both the parameters can be measured with the same sensor. Due to the independent measurement parameters (open circuit voltage and sensor resistance ), the sensing model is greatly attractive for measurements without cross-sensitivity. The highly resilient temperature and strain sensor show excellent linearity, repeatability and good sensitivity. Besides, due to the compatibility of the fabrication scheme to low temperature processing of the flexible materials and to mass volume production, printed fabrication methodologies were adopted to realize the sensor. This promises low cost production and a disposable nature (single use) of the sensor patch. The temperature-strain dual parameter semi-transparent sensor has been further tested on mice wounds in vivo. The preliminary experiments on mice wounds offer prospects for developing smart, i.e. sensorized, wound dressings for clinical applications.

An Intelligent Control Strategy for a Highly Reliable Microgrid in Island Mode

An intelligent control strategy based on a membership cloud model in a high reliable off-grid microgrid with a reconfigurable inverter is proposed in this paper. The operating principle of the off-grid microgrid with the reconfigurable inverter is provided, which contains four operating modes. An open-circuit fault diagnosis for the inverter is presented first. The polarities of the midpoint voltages defined in the paper are used to recognize the faulty power switch. The reconfigurable inverter allows the power switches of different bridges to be reconfigured, when there are power switches faulty, to let the inverter operate in faulty state. The working principle of the reconfigurable inverter is given. The membership cloud model with two output channels is built to obtain the virtual impedance to suppress the circulating currents between inverters when the reconfigurable inverter is in faulty state. A pulse resetting method is presented. The general intelligent control strategy for the reconfigurable inverter is formed as the droop-virtual impedance-voltage-current-pulses resetting control. The validity of the intelligent control strategy of the system is verified by simulation.

A Novel Dye-Sensitized Solar Cell Structure Based on Metal Photoanode without FTO/ITO

Traditional dye-sensitized solar cells (DSSC) use FTO/ITO containing expensive rare elements as electrodes, which are difficult to meet the requirements of flexibility. A new type of flexible DSSC structure with all-metal electrodes without rare elements is proposed in this paper. Firstly, a light-receiving layer was prepared outside the metal photoanode with small holes to realize the continuous oxidation-reduction reaction in the electrolyte; Secondly, the processing technology of the porous titanium dioxide (TiO2) film was analyzed. By testing the J–V characteristics, it was found that the performance is better when the heating rate is slow. Finally, the effects of different electrode material combinations were compared through experiments. Our results imply that in the case of all stainless-steel electrodes, the open-circuit voltage can reach 0.73 V, and in the case of a titanium photoanode, the photoelectric conversion efficiency can reach 3.86%.