Resistance Capacitance Research Articles

Electric characteristics of calcium-phosphate ceramics with impurities

The electrical characteristics of calcium phosphate materials have been studied at various frequencies in the temperature interval from room temperature to 1200 °C. It has been shown that the electrical characteristics (relative permittivity, capacitance, and electric resistance) change with the annealing temperature. Temperature changes in these characteristics are associated with the presence of impurities in the studied samples, as well as the nonstoichiometry of the phase composition of the initial samples. The phase composition and structure of the studied samples were studied by X-ray diffraction, Mass-spectrometry, and IR-spectroscopy. It has been shown that the studied calcium-phosphate samples have dielectric properties. The temperature intervals for the stability of the electrical characteristics of these materials have been established.

Performance Assessment of Frequency Selective Grounding for Grid-Connected Photovoltaic Systems

Photovoltaic (PV) panels and their grid-connection circuitries have to be grounded to comply with various standards and industrial codes. Objectives of grounding a PV system include limiting ground currents and potentials, supporting the operation of protective devices therein, and preventing the accumulation of static charges on PV panels. These objectives can be translated into design constraints for an impedance to connect a PV system to the ground. This paper presents the design and performance assessment of a frequency selective grounding (FSGR) for grid-connected PV systems. The proposed FSGR is composed of a parallel <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$R$</tex-math></inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$L$</tex-math></inline-formula> , and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$C$</tex-math></inline-formula> circuit, which provides a resistive path for dc currents and a low capacitive impedance path for harmonic currents. The FSGR is designed and experimentally tested for a 2 kW, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> , laboratory grid-connected PV system under fault and non-fault conditions. The performance of the proposed grounding is also compared with the solid grounding under similar conditions to further assess its capabilities. Experimental results show that the FSGR can reduce ground currents, limit ground potentials, and reduce the dc leakage currents. These observed features are complimented with minor effects on the operation of protective devices in a grid connected PV system.

Comparative Study of the Parameter Acquisition Methods for the Cauer Thermal Network Model of an IGBT Module

Under the operating conditions of high power and high switching frequency, an insulated gate bipolar transistor (IGBT) chip can produce relatively large power loss, causing the junction temperature to rise rapidly; consequently, the reliability of the IGBT module can be seriously affected. Therefore, it is necessary to accurately predict the junction temperature of the IGBT chip. The resistance capacitance (RC) thermal network model is a commonly used method for IGBT junction temperature prediction. In this paper, the model parameters are obtained by two methods to establish the Cauer thermal network models of the IGBT module. The first method is to experimentally obtain the transient thermal impedance curve of the IGBT module and the structure function and then extract the individual thermal parameters of the Cauer thermal network model; the second method is to obtain the thermal parameters of the thermal network model directly by using theoretical formulas that consider the influence of the heat spreading angle. The predicted junction temperatures of the Cauer thermal network models established by the two methods are compared with the junction temperatures obtained from infrared (IR) measurements during the power cycling test, the junction temperatures measured by the temperature-sensitive electrical parameter (TSEP) method, and the junction temperatures calculated by finite element (FE) analysis. Additionally, the Cauer thermal network models established by the two methods are compared and verified. The results indicate that the Cauer thermal network model established based on theoretical formulas can accurately predict the maximum junction temperature of the IGBT chip, and the calculated temperature for each layer, from the IGBT chip layer to the ceramic layer, also accords well with the FE results. The Cauer thermal network model established based on the experimental test and the structure function can accurately predict the average junction temperature of the IGBT chip.

Impact of TECAR therapy on post-natal rectus diastasis: A randomized trial

Background. Rectus diastasis is a common problem affecting postpartum mothers. It decreases the integrity as well as functional strength of the abdominal wall, and causes low back pain and pelvic instability Objective. To examine how TECAR therapy (monopolar capacitive resistance radiofrequency of 448 KHz) affects rectus diastasis in postpartum women. Design. A prospective randomized controlled trial. Setting. Outpatient physical therapy clinic, Kafr El Sheikh University. Methods. Forty postnatal women having diastasis recti abdominis (DRA) &gt; 2.5 cm were recruited and randomized into two equal groups; the control group received a program of selected abdominal exercises and low caloric diet of 1200 kcal/ day for 4 weeks, and the study group received the same control group interventions in addition to TECAR application. DRA degree was the primary outcome, while weight and body mass index measures were the secondary outcomes. All variables were measured at the baseline and after 4 weeks of the intervention by rectus diastasis test, abdominal ultrasonography, and calibrated weight scale. Results. Analysis showed a significant reduction (P &lt; .05) in weight, body mass index, rectus diastasis test, and ultrasound measures in both groups in favor of the study group Conclusion. Using TECAR with a standard program of abdominal exercises and low caloric diet has more beneficial effects on postnatal DRA than practicing the exercise program alone with the low-calorie diet.

Perbandingan Sensor TEV Dan Detektor RC Untuk Pengukuran Partial Discharge Pada Peralatan Tegangan Tinggi

Electrical equipment often faces various issues, with insulation problems being a major cause of failure. This article investigates the comparative effectiveness of two Partial Discharge (PD) detection methods: using Transient Earth Voltage (TEV) sensors and Resistor-Capacitor (RC) detectors. The study was conducted on a metal box with a voltage level of 6 kV. Data collected included Background Noise (BGN) and Partial Discharge Inception Voltage (PDIV), processed using Microsoft Excel and OriginPro 9. Results indicate a correlation between higher BGN values on TEV sensors and earlier PDIV occurrence on those sensors. Background noise significantly impacts the PDIV threshold, influencing sensitivity and insulation risk potential. While PDIV provides a threshold guideline, correlation with BGN helps illustrate the background conditions' influence on PD measurement outcomes. The study offers insights into the importance of considering noise in PD measurements and formulates recommendations for practitioners to choose appropriate detection methods based on specific environmental conditions and electrical equipment.

Integrated optics based on electro optic modulators for long distance links and high bit rate communication

Abstract This paper has clarified the gallium aluminum arsenide and plastic modulators and its element circuit modeling design considerations for high signal processing distance links communications. Modulator circuit model design considerations and equations analysis are taken into account. Modulator source resistance, modulator inductance, and modulator capacitance based electro-optic modulator (EOM) is studied and analyzed against temperature variations. In addition to the switching voltage for EOM is analyzed at both 1300 nm and 1550 nm wavelength versus temperature variations. The operation efficiency and maximum modulation resonance frequency are studied for previous and proposed EOM versus modulator length variations. The lower modulator resistance, modulator capacitance, and modulator inductance can be achieved with the proposed EOM. As well as the proposed EOM has outlined the optimum operational efficiency and maximum resonance modulation frequency compared to the previous EOM.

Application of the Producer-Based Capacitance Resistance Model to Undersaturated Oil Reservoirs in Primary Recovery

Summary We investigated the application and usefulness of the producer-based representation of the capacitance resistance model (CRM) to characterize single and multiwell undersaturated oil reservoirs during primary recovery. The CRM is a physics-based, data-driven method that has been amply used to model reservoirs under different recovery stages, particularly during flooding processes. However, there have been very few applications to primary recovery. The previous work on primary recovery used the rate and bottomhole pressure (BHP) data to calculate the time constant or storage capacity, and the productivity index (PI) associated with each production well. Here, we incorporate popular productivity models in CRM, making the results comparable with those from pressure transient analysis (PTA) or rate transient analysis (RTA). We also investigate various topics that have not been discussed or that deserve a further explanation to include CRM in the reservoir engineering toolbox. These comprise constant and variable rate wells, transient flow, well location, well geometry, anisotropy, and different types of reservoir heterogeneity. CRM is systematically compared and validated against analytical and numerical models of single and multiwell reservoirs. We also use it to characterize flow in a real oil reservoir . Our results demonstrate that CRM can provide important parameters for reservoir characterization using BHP and rate data acquired from routine production operations, that is, without the need to shut in wells or perform dedicated tests. It yields reasonable estimates of flow resistance properties that depend on reservoir geology, petrophysics, and well condition. It can also be applied during successive time intervals to assess changes in well-reservoir properties, such as drainage radius or the PI, an indication of well damage. Most importantly, we show that for several well-reservoir cases with multiple complexities, CRM can accurately capture the reservoir size, or the drainage pore volume (PV) associated with each well in developed fields, which enables the calculation of average pressure and helps assess interwell communication and opportunities for infill drilling.

Dissipation and amplification management in an electrical model of microtubules: Hybrid behavior network

The control of dissipation and amplification of solitary waves in an electrical model of a microtubule is demonstrated. This model consists of a shunt nonlinear resistance–capacitance (J(V)–C(V)) circuit and a series resistance–inductance (R–L) circuit. Through linear dispersion analysis, two features of the network are found, that is, low bandpass and bandpass filter characteristics. The effects of the conductance’s parameter λ on the linear dispersion curve are also analyzed. It appears that an increase of λ induces a decrease (an increase) of the width of the bandpass filter for positive (negative) values of λ. By applying the reductive perturbation method, we derive the equation governing the dynamics of the modulated waves in the system. This equation is the well-known nonlinear Schrödinger equation extended by a linear term proportional to a hybrid parameter σ, i.e., a dissipation or amplification coefficient. Based on this parameter, we successfully demonstrate the hybrid behavior (dissipation and amplification) of the system. The exact and approximate solitary wave solutions of the obtained equation are derived, and the effects of the coefficient σ on the characteristic parameters of these waves are investigated. Using the analytical solutions found, we show numerically that the waves that are propagated throughout the system can be dissipated, amplified, or remain stable depending on the network parameters. These results are not only in agreement with the analytical predictions, but also with the existing experimental results in the literature.

Multiobjective Particle Swarm Optimization to Design the Top Load of a Very Low Frequency Thirteen-Tower Umbrella Antenna

In this paper, an innovative method for designing the top load of a very low frequency (VLF) thirteen-tower umbrella antenna based on multiobjective particle swarm optimization (MOPSO) is proposed. The design of the thirteen-tower umbrella antenna’s top load mainly involves the sag and position distribution of the cables. On the basis of analyzing the influence of the cables’ sag on the antenna’s radiation efficiency, a MOPSO based on the Pareto optimality is used to optimize the location distribution of the antenna top load catenaries. The radiation resistance and static capacitance of the antenna can be both slightly improved when each diamond-shaped top load maintains 8 top load cables, while the radiation resistance and static capacitance of the antenna can be improved by more than 6% when each diamond-shaped top load is increased to 10 top load cables.

Effect of Supporting Electrolyte on Capacitance and Impedance Properties of Electrodeposited PEDOT/ERGO Electrodes for Supercapacitor

In this study, the ability of Poly (3,4-ethylenedioxythiophene)/electrochemically reduced graphene oxide (PEDOT/ERGO) electrodes for supercapacitors to store electrical energy is studied. PEDOT/ERGO electrodes are produced using a simple two-step electrochemical method that involves electrochemically reduction of graphene oxide, and then PEDOT is electrochemically deposited onto the ERGO in different electrolyte solutions. Electrochemical techniques such as cyclic voltammetry (CV), galvanostatic charge discharge (GCD), and electrochemical impedance spectroscopy (EIS) are utilized to investigate the electrochemical characteristics of PEDOT/ERGO electrodes produced in different electrolyte systems including 0.1 M lithium perchloride/acetonitrile (LiClO4/ACN), tetraethylammoniumtetrafluoroborate/acetonitrile (Et4NBF4/ACN), and tetrabutylammonium hexaflorophosphate/acetonitrile (Bu4NPF6/ACN). The electrolyte type has a significant impact on electrochemical results. PEDOT/ERGO manufactured in LiClO4/ACN demonstrates a high specific capacitance (Csp) and low charge transfer resistance (Rct). According to results, the Csp value is decreased in the following order; 26.48 mFcm-2 for LiClO4, 20.58 mFcm-2 for Et4NBF4, 8.96 mFcm-2 for Bu4NPF6.

State of energy estimation of the echelon-use lithium-ion battery based on Takagi–Sugeno fuzzy optimization

Owing to the degradation of an echelon-use lithium-ion battery (EULIB), the Ohmic internal resistance (OIR) and actual capacity (AE) have both changed greatly, and the state of energy (SOE) can more accurately represent the state of a EULIB than the state of charge (SOC) because of the working voltage. To improve the accuracy and adaptability of SOE estimation, in the paper, we study the energy state estimation of a EULIB. First, the four-order resistor–capacitance equivalent model of a EULIB is established, and an unscented transformation is introduced to further improve the estimation accuracy of the SOE. Second, a EULIB’s SOE is estimated based on adaptive unscented Kalman filter (AUKF), and the OIR and AE of a EULIB are estimated based on the AUKF. Third, a Takagi–Sugeno fuzzy model is introduced to optimize the OIR and AE of the EULIB, and the SOE estimation method is established based on an adaptive dual unscented Kalman filter (ADUKF). Through simulation experiments, verification, and comparison, energy decayed to 80%, 60%, and 40% of the rated energy, respectively, even with a large initial error; with the initial value of the SOE starting at 100%, 60%, or 20%, the estimated SOE can track the actual value. It can be seen that the method has a strong adaptive ability, and the estimation accuracy error is less than 1.0%, indicating that the algorithm has high accuracy. The method presented in this paper provides a new perspective for SOE estimation of EULIBs.

Li-ion battery charge transfer stability studies with direct current impedance spectroscopy

The safety of lithium-ion batteries is closely related to the charge transfer process inside the battery. With the rapid increase in battery usage, battery safety issues have become increasingly prominent. Due to technical limitations, the current battery thermal failure management system cannot realize risk early warning. Charge transfer resistance (Rct) is a macroscopic parameter characterizing the battery transport process, which can be detected by electrochemical impedance spectroscopy (EIS). Due to the high cost of EIS test equipment and high signal-to-noise ratio requirements, it is still not applicable to electric vehicles. In addition, Rct is affected by ambient temperature and battery aging, which brings challenges to online safety diagnosis. Here we propose a method to obtain the activation energy of a battery using direct current impedance spectroscopy (DCIS), which enables the stability diagnosis of the charge transport process. DCIS is a time-domain impedance spectroscopy technique. It uses the time constant characteristic of the internal resistor–capacitor network to detect battery parameters. Activation energy is the energy barrier for lithium-ions to cross the electrode/electrolyte interface and can indicate the stability of the charge transport process. Since activation energy is a microscopic parameter, it is not affected by temperature and aging, which is beneficial for battery safety diagnosis. The experimental results show that the charge transfer process of the sample cells with a state of health (SOH) greater than 80% is stable. When the SOH is less than 80%, the activation energy drops rapidly from 0.55 eV to 0.16 eV, indicating an increased risk of thermal runaway. Since DCIS supports online detection, it provides an option for safety diagnosis of electric vehicle batteries.

Magnetorheological semi-active shock mitigation control. Part I: numerical analysis and preliminary tests

Minimizing shock loads transmitted to sensitive structures or equipment is the objective of shock mitigation control. The core of shock mitigation control using magnetorheological (MR) energy absorber (EA) to minimize impact load is to make full use of the piston stroke of MREA so as to achieve “soft-landing.” The key lies in the precise description of the hysteresis of MREA and the shock mitigation control method. In this part, a single-degree-of-freedom (SDOF) shock mitigation control system using MREA is established, and the corresponding dynamic model and drop-induced shock mitigation test system are established. Based on the optimal Bi number control method and constant force control theory, feedforward controllers featuring resistor-capacitor (RC) operator-based hysteresis model and Bingham model are established to realize “soft-landing” in sequence. Specific performance evaluation indexes for shock mitigation control systems, that is, average velocity change rate (AVCR) and velocity-acceleration conversion ratio (V-ACR), are proposed. The effectiveness of shock mitigation control methods with different models on the MREA-based shock mitigation control system in profiles of simulation and tests are compared and analyzed.

Insights into the weathering behavior of pyrite in alkaline soil through electrochemical characterizations: Actual hazards or potentially benefits?

Pyrite is the most common metal sulfide mineral in the crust and readily weathers under natural circumstances to release H+ to acidify surrounding groundwater and soil, resulting in heavy metal ions in the surrounding environment (e.g., meadow and saline soils). Meadow and saline soils are two common, widely distributed alkaline soils and can affect pyrite weathering. Currently, the weathering behaviors of pyrite in saline and meadow soil solutions have not been systematically studied. Electrochemistry coupled with surface analysis methods were employed to study pyrite weathering behaviors in simulated saline and meadow soil solutions in this work. Experimental results suggest that saline soil and higher temperatures increase pyrite weathering rates due to the lower resistance and greater capacitance. Surface reactions and diffusion control the weathering kinetics, and the activation energies for the simulated meadow and saline soil solutions are 27.1 and 15.8 kJ mol−1, respectively. In-depth investigations reveal that pyrite is initially oxidized to Fe(OH)3 and S0, and Fe(OH)3 further transforms into goethite γ-FeOOH and hematite α-Fe2O3, while S0 ultimately converts into sulfate. When these iron compounds enter alkaline soils, the alkalinity of soil changes, and iron (hydr)oxides effectively reduce the bioavailability of heavy metals and benefit alkaline soils. Meanwhile, weathering of natural pyrite ores containing toxic elements (such as Cr, As, and Cd) makes these elements bioavailable and potentially degrades the surrounding environment.

Exertional Cardiac and Pulmonary Vascular Hemodynamics in Patients With Heart Failure With Reduced Ejection Fraction

BackgroundExertional dyspnea is a cardinal manifestation of heart failure with reduced ejection fraction (HFrEF), but quantitative data regarding exertional hemodynamics are lacking. ObjectivesWe sought to characterize exertional cardiopulmonary hemodynamics in patients with HFrEF. MethodsWe studied 35 patients with HFrEF (59 ± 12 years old, 30 males) who completed invasive cardiopulmonary exercise testing. Data were collected at rest, at submaximal exercise and at peak effort on upright cycle ergometry. Cardiovascular and pulmonary vascular hemodynamics were recorded. Fick cardiac output (Qc) was determined. Hemodynamic predictors of peak oxygen uptake (VO2) were identified. ResultsLeft ventricular ejection fraction and cardiac index were 23% ± 8% and 2.9 ± 1.1 L/min/m2, respectively. Peak VO2 was 11.8 ± 3.3 mL/kg/min, and the ventilatory efficiency slope was 53 ± 13. Right atrial pressure increased from rest to peak exercise (4 ± 5 vs 7 ± 6 mmHg,). Mean pulmonary arterial pressure increased from rest to peak exercise (27 ± 13 vs 38 ± 14 mmHg). Pulmonary artery pulsatility index increased from rest to peak exercise, while pulmonary arterial capacitance and pulmonary vascular resistance declined. ConclusionsPatients with HFrEF suffer from marked increases in filling pressures during exercise. These findings provide new insight into cardiopulmonary abnormalities contributing to impairments in exercise capacity in this population. Clinical Trial Registrationclinicaltrials.gov identifier: NCT03078972

A New Electrical Resistance Measurement Method of Carbon Fiber-Reinforced Polymer Tubes Based on C⁴D Technique

This work introduces the capacitively coupled contactless conductivity detection ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{C}^{{4}}\text{D}$ </tex-math></inline-formula> ) technique into nondestructive testing (NDT) of carbon fiber-reinforced polymer (CFRP) and proposes a new resistance measurement method of CFRP tubes. The proposed method does not require direct contact between the electrodes and the carbon fiber. Therefore, the electrical resistance of CFRP can be measured without the treatments required by traditional electrical methods that may lead to surface or structural damage. The equivalent circuit model of the new method is established, and the challenges are analyzed. Simulation and experiment are conducted with woven fabric CFRP tubes to verify the feasibility of the proposed method, including the range of workable frequency, the effectiveness of the circuit model, and the capability of damage detection. Research results show that a relatively high working frequency is required to accurately measure the interested resistance and sense the resistance change. By selecting a workable frequency, the effectiveness of the circuit model is verified. Research results indicate that the stray capacitance between the electrodes has little effect on resistance measurement, and the capacitor–resistor–capacitor model is still applicable. Research results also verify the feasibility of the proposed method for damage detection. It is able to sense the resistance change resulted from the damage of CFRP, either the conductivity changes in simulation or actual cutting damage in experiment.

Investigation of replacing tracer flooding analysis by capacitance resistance model to estimate interwell connectivity

Interwell connectivity is an essential parameter for managing waterflooding operations in a field. Analysis of the tracer injection operation is a well-known approach to studying injected fluids distribution in a reservoir and toward producer wells. Developed in the early 2000s, Сapacitance-Resistance Model (CRM) is an analytical approach for waterflooding modeling and optimization. Production/injection data are used as input to model the mass balance and estimate parameters such as the interwell connectivity. In this work, we investigated the accuracy of applying the Capacitance-Resistance Model to mimic a tracer test. Such an approach helps assess the connection between the wells and decide on further field development steps cheaper and quicker. Connectivity values estimated by tracer tests and CRM were analyzed and compared for synthetic and real fields. CRM was capable of modeling waterflooding and estimating production in both fields with acceptable accuracy. Parameters such as well spacing and fluid loss during the injection were considered to improve the accuracy of the CRM approach to calculate the interwell connectivity between injector/producer pairs. Our study showed that CRM could serve as a tool for a quick approximate estimation of interwell connectivity under certain assumptions and is recommended as a replacement for tracer flooding analysis, where the tracer test is not possible or is expensive.

영동권 실 계통 PMU 측정정보를 활용한 울진, 삼척 산불 시 SSR 위험성 검토

The role of the power grid in the power system is to transmit the power produced at the power generation sites to the demand sites without interruption. When a new power source plan is established, a new power grid plan is also established so that necessary power grid construction is carried out at an appropriate time. However, the construction of a new power grid is not easy due to the problem of location selection and economic reasons. For this reason, efforts have been made for a long time to find ways to increase the capacity of the grid to avoid the construction of the new grid. A typical one of them is a method of increasing power transmission capacity by compensating the series capacitive impedance of the power transmission network. Therefore, KEPCO, in response to the delay in the construction of a new power grid for the construction of a large-scale power generation complex in the Yeongdong area, it was decided to increase the power transmission capacity of the existing power grid through series capacitive impedance. However, there is a risk that such an increase in transmission capacity through impedance compensation may cause problems such as sub synchronus resonance (SSR). In case of SSR, occured when the resonance frequency of the impedance-compensated power grid coincides with the mechanical resonance frequency of the nearby generator, and if a mechanical burden is accumulated on the generator shaft, the shaft may break. For this reason, the power authorities reviewed the risk of SSR and installed thyristor controlled series capacitor (TCSC) based on the results to avoid dangerous frequency bands by adjusting the apparent impedance of the impedance-compensated transmission line. In this way, the risk of SSR was responded to through sufficient preparation for impedance compensation. However, in the case of wild fires in Uljin and Samcheok, which occurred in March 2022, a number of transmission lines were opened, and the network topology between the compensation line and the nearby generator approached the condition of SSR, increasing the risk of resonance. This paper analyzes the risk of actual SSR based on the system configuration during wildfires in Uljin and Samcheok and the system operation information obtained through the Phase Measurement Unit (PMU) located nearby sites.

Modeling and analysis of a piezoelectric transducer embedded in a nonlinear damped dynamical system

This paper focuses on the dynamical analysis of the motion of a new three-degree-of-freedom (DOF) system consisting of two segments that are attached together. External harmonic forces energize this system. The equations of motion (EOM) are derived utilizing Lagrangian equations, and the approximate solutions up to the third order are investigated using the methodology of multiple scales. A comparison between these solutions and numerical ones is constructed to confirm the validity of the analytic solutions. The modulation equations (ME) are acquired from the investigation of the resonance cases and the solvability conditions. The bifurcation diagrams and spectrums of Lyapunov exponent are presented to reveal the different types of the system’s motion and to represent Poincaré maps. The piezoelectric transducer is connected to the dynamical system to convert the vibrational motion into electricity; it is one of the energy harvesting devices which have various applications in our practical life like environmental and structural monitoring, medical remote sensing, military applications, and aerospace. The influences of excitation amplitude, natural frequency, coupling coefficient, damping coefficient, capacitance, and load resistance on the output voltage and power are performed graphically. The steady-state solutions and stability analysis are discussed through the resonance curves.

Distributed state-of-charge estimation for lithium-ion batteries with random sensor failure under dynamic event-triggering protocol

The state of charge (SOC) performs as an indicator of the remaining capacity of the Lithium-ion batteries (LBs). An accurate SOC estimation of LB is of great significance for its operation optimization and life extension of the battery. In this article, the issue of distributed SOC estimation is addressed for LBs. To design the distributed filter for SOC estimation, the equivalent circuit model comprised of the resistor–capacitor networks, Warburg element, ohmic resistance, battery current and voltage is established. In order to reflect the properties of the random sensor failure (RSF) well, a set of Bernoulli-distributed sequences with known probabilities is introduced. The communication resources over the wireless networks are usually limited, for the purpose of saving communication resources, the dynamic event-triggering mechanism (DETM) is adopted to regulate transmission of the signals. The main objective of this article is to design a distributed SOC estimation approach for LBs subject to RSF under DETM over the sensor networks. The upper bound of the estimation error covariance is first ensured and then such upper bound is minimized by parameterizing the estimator gain. In addition, by virtue of the matrix simplification technique, the issue of sensor network topology’s sparseness is effectively tackled. At last, experimental examples are employed to validate the feasibility of the developed distributed SOC estimation algorithm.