Measurement Of Internal Resistance Research Articles

Anti‐biofouling anion exchange membrane using surface modified quaternized poly(ether imide) for microbial fuel cells

ABSTRACTThis article deals with a novel way of improving the anti‐biofouling potential of an anion exchange membrane (AEM) by surface modification with ethanol amine (AEOH), a low cost material without affecting the chemical structure and morphology of Quaternized Poly(ether imide) (QPEI), the host membrane. The anti‐biofouling potential of the AEM was evaluated using bacteria anti‐adhesion test, hydrophilicity, surface roughness, water uptake, and the AEOH modification time. The data reveal that power density in all MFCs attain the highest in the sixth batch and thereafter declined albeit in a varying rate as expected measuring the least for QPEI‐30. Periodical measurement of internal resistance and protein content on the membrane surfaces were found to be the least for QPEI‐30 when compared with others. A reduced biofouling with improved anti‐biofouling property is attributed to the enhanced hydrophilicity due to surface modification. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44432.

Real-Time Estimator Li-ion Cells Internal Resistance for Electric Vehicle Application

Battery Management Systems (BMS) were introduced into Li-ion battery packs to serve several purposes, among which assertion of the small variations of the cells state of charge and increase of their life cycle. This paper offers a complete real-time working model for the on-line measurement of the cells internal resistance, which requires very low computation time and enough precision for electric vehicle applications. Some electric models used for the determination electrical parameters have a huge complexity and are not implementable in automotive processing units. Among many solutions, the proposed approach uses cell modeled as a source-resistance with low complexity, without loss measurement precision, or increase the computation capabilities.

Development of Mathematical Equation for Photovoltaic Array Internal Resistance Measurement under Operating Conditions

A novel technique has been developed for PV array internal resistance measurement while keeping the plant in operation in contrary to flash test or basic equation (Eb) for which the modules need to be disconnected from the system. We present an equation developed for the array’s internal resistance measurement for PV technologies namely Amorphous Silicon (a-Si), Poly Crystalline Silicon (p-Si) and Hybrid Crystalline Silicon (HIT). Monthly Measured I-V characteristic curves of PV Array were converted to Standard Test Conditions following the IEC 60891 standard. Multiple regression analysis and linear regression technique were used to develop the equation for estimating the PV array internal resistance. The developed equations (Ed) will find the relationships of the 4 variables that are Series resistance (Rs), Shunt resistance (Rsh), maximum voltage (Vm) and maximum current (Im). The results revealed that the Ed can be applied to measure the PV array internal resistance value with low error margin than Eb. The series resistance calculated using Ed is higher than Eb about 1.11 %, 1.88 % and 0.87 % for a-Si, p-Si and HIT respectively. The shunt resistance calculated using Ed is higher than Eb about 0.07 %, 0.09 % and 0.09% for a-Si, p-Si and HIT respectively.

A novel health indicator for on-line lithium-ion batteries remaining useful life prediction

Prediction of lithium-ion batteries remaining useful life (RUL) plays an important role in an intelligent battery management system. The capacity and internal resistance are often used as the batteries health indicator (HI) for quantifying degradation and predicting RUL. However, on-line measurement of capacity and internal resistance are hardly realizable due to the not fully charged and discharged condition and the extremely expensive cost, respectively. Therefore, there is a great need to find an optional way to deal with this plight. In this work, a novel HI is extracted from the operating parameters of lithium-ion batteries for degradation modeling and RUL prediction. Moreover, Box-Cox transformation is employed to improve HI performance. Then Pearson and Spearman correlation analyses are utilized to evaluate the similarity between real capacity and the estimated capacity derived from the HI. Next, both simple statistical regression technique and optimized relevance vector machine are employed to predict the RUL based on the presented HI. The correlation analyses and prediction results show the efficiency and effectiveness of the proposed HI for battery degradation modeling and RUL prediction.

A Combined Aging and Abuse Study of Li-Ion Cells

Lithium-ion batteries have been powering a wide range of electrical and electronic devices, from consumer products and medical equipment to automotive systems and space applications. Some highly publicized failures of products powered by lithium ion cells, such as laptops, cellphones and electronic toys, have been reported recently. A portion of these failures has been linked to overheating of the battery resulting in fire and explosion. Overall, these incidents have catalyzed a great deal of research and design activities aimed at trying to understand the causes of such failures and help guide safer cell designs. In this work, the degradation mechanisms in commercial 18650 lithium ion cells, due to long term cycling under nominal-use charge discharge cycling as well as under electric vehicle drive cycling, are studied. In addition, studies were carried out after subjecting the cells to overcharge and external short circuit testing on fresh as well as cycled cells. During the external short test, the cells were subjected to a low resistance load (50 mΩ). Actual results indicate that for a very short time the cell experiences a very high current causing a rise in the cell temperature (>70 oC). In the overcharge test, the cell is charged up at a constant C-rate until the test is stopped due to either an abnormal event or the cell protection activation. Preliminary results have shown lithium metal deposition, as expected, in the negative electrode once that the intercalation rate has been overcome by the diffusion rate. Also, cell temperature has shown a significant increment during the overcharge process. Finally, the electrodes and electrolyte from the cycled cells were subjected to a similar analysis to understand the degradation mechanisms in long term use as well as to understand their behavior under abuse conditions after long term use. Understanding what causes this temperature rise and its effect on the electrodes could provide some information about how to prevent thermal runaway in cells and batteries used in various applications for long periods. The cells under these tests have been characterized by conducting a Destructive Physical Analysis (DPA). The study is being accomplished through charge/discharge cycling, internal resistance measurement, capacity fading, and impedance spectroscopy. Cell temperatures are monitored in all the experiments. The morphological changes are studied by extracting the electrodes from the abused cells and analyzing them by microscopy and spectroscopy techniques. This analysis will help to obtain the changes in the electrochemical properties of the cell as well as its morphology.

Research of DC Panel Battery Fault Detection Method

This paper elaborates the DC screen and battery DC screen fault detection method. The method of measuring battery’s internal resistance and voltage is analyzed and studied in this paper, and the two methods are optimized. Besides, the structure of the battery internal resistance, internal resistance equivalent principle and other aspects are also introduced in this paper. The optimal measurement scheme can be chosen by comparing the internal resistance measurement of DC discharge method and the AC signal injection method.

On-line Measurement of Internal Resistance of Lithium Ion Battery for EV and Its Application Research

Internal resistance of the battery can really reflect its own characteristics, which including health status of the battery, inconsistency, state of charge, thermal runaway. On-line measurement of internal resistance can real-time monitor the running state of each battery and accurately, can report fault state of the battery and handle fault in time. This paper implements the practical engineering module of on-line measurement of internal resistance of lithium ion battery for EV (Electric Vehicle) using AC analysis. The detection precision and stability of the module are less than 0.3%. Based on experiments, the paper studies the stability and temperature characteristic of internal resistance of lithium battery. It also studies the relationship between the internal resistance and SOC, charging current with experiments. This paper analyzes the relationship between the internal resistance and default of the battery, such as inconsistency of batteries, excessive charging current, changing of work state, overcharging.

Filter Design of Power Battery Resistance Measuring for New Energy Vehicle

In order to measure the internal resistance of new energy vehicle power battery precisely, the high quality factor analog band-pass filter circuit and switched-capacitor circuit was studied. And the circuit was redesigned by using a switched capacitor circuit for digital control. Combined with the requirements of vehicle battery internal resistance measurement, the resistance measurement system architecture which is based on microcontroller and programmable logic devices is proposed. Finally, the system is validated via error calculation and the actual experiments.

Online Measurement of Battery Internal Resistance Based on AC Impedance Method

In this paper, the merit and disadvantage of existing measurement methods for battery internal resistance are firstly analyzed. Then an online internal resistance measurement based on AC impedance method is proposed, which can increase the stability of the excitation source and enhance the performance of the filtered feedback signal. The method can be used to measure the small resistance of lithium-ion battery precisely. Experimental results show that the proposed method is accurate.

Resistance Measurement Design of the Battery Based on LabVIEW

In order to improve the accuracy of the measurement of battery internal resistance, a lead-acid battery internal resistance measurement system was designed using the AC injection method and LabVIEW software. The system is based on LabVIEW software, design a stable sin signal produce program and data acquisition program. At the same time, Signal conditioning modules which were developed by NI were used to suppress the noise. The experiment results show that the system easy to use and has a high accuracy.

State-of-Charge Estimation and State-of-Health Prediction of a Li-Ion Degraded Battery Based on an EKF Combined With a Per-Unit System

This paper describes the application of an extended Kalman filter (EKF) combined with a per-unit (p.u.) system to the identification of suitable battery model parameters for the high-accuracy state-of-charge (SOC) estimation and state-of-health (SOH) prediction of a Li-Ion degraded battery. Variances in electrochemical characteristics among Li-Ion batteries caused by aging differences result in erroneous SOC estimation and SOH prediction when using the existing EKF algorithm. To apply the battery model parameters varied by the aging effect, based on the p.u. system, the absolute values of the parameters in the equivalent circuit model in addition to the discharging/charging voltage and current are converted into dimensionless values relative to a set of base value. The converted values are applied to dynamic and measurement models in the EKF algorithm. In particular, based on two methods such as direct current internal resistance measurement and the statistical analysis of voltage pattern, each diffusion resistance <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(R_{\rm Diff})$</tex></formula> can be measured and used for offline and online SOC estimations, respectively. All SOC estimates are within <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\pm$</tex></formula> 5% of the values estimated by ampere-hour counting. Moreover, it is shown that <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$R_{\rm Diff}$</tex></formula> is more sensitive than other model parameters under identical experimental conditions and, hence, implementable for SOH prediction.

In Vitro Evaluation of Nitinol Stone Retrieval Baskets for Flexible Ureteroscopy

Because of increased clinical relevance of retrograde intrarenal surgery (RIRS), a variety of stone retrieval baskets have been introduced into endourology. Differences in shape and material may have consequences in performance and efficacy of RIRS. The aim of the study was to evaluate the in vitro performance of multiple commercially available nitinol retrieval baskets. Ten manufacturers of baskets for RIRS were invited to participate in this evaluation. The evaluation included measurement of the basket's internal resistance toward deflection, the influence on the deflection angle of a flexible ureteroscope (URF-P5, Olympus), and basket function in maximum deflection of the scope. All measurements were performed five times. Nine manufacturers, providing a total of 15 baskets, decided to participate in this evaluation. Maximum deflection of the ureteroscope (275 degrees) was achieved in 12 baskets and reduced in 3. In maximum deflection, complete opening of the basket was possible in 13 samples. In one case, partial opening of the basket was possible; one basket failed. The measurement of the basket's internal resistance showed wide variations (5.97 to 38 mm deflection/g), consecutively leading to increased inner radius of the fully deflected scope in 10 of 15 tested samples. The tested baskets showed wide variations in their resistance toward bending. Influence on overall deflection capacity seems minor, however. On the other hand, higher resistance leads to increased inner radius of the fully deflected renoscope, which may alter functionality. Knowledge about the basket's key feature and differences in basket performance may be crucial to choose the best tool for the patient.

Test of battery internal resistance

Responding the problem in the measurement of battery internal resistance that it is difficult to improve the accuracy because of the power supply ripple and many other factors, a method used chaotic oscillator is studied. Using the principle that chaotic oscillator is sensitive to initial value this method simplifies the measuring circuit and ignores the anti-interference circuit. To combine the good inhibitory effect on noise to AC internal resistance detection method, the on-line detection is realized.

К вопросу об измерении сопротивления химических источников тока (ХИТ)

The analysis of existing methods of measurement of internal resistance of chemical current sources (CCS) was carried out. Their shortcomings were noted. The method of measurement of full internal resistance the CCS based on the analysis of transient characteristics of a charge from it of the condenser of known capacity is considered.

Automatic Measurement for Internal Resistance of Battery in Uninterruptible Power Source

Automatic Measurement for Internal Resistance of Battery in Uninterruptible Power SourceThis paper considers the approach to the measurement of internal resistance of the battery in the uninterruptible power sources (UPSs [1]). Advantages of the approach are the measurements in power supplies without switching-off the battery, simplicity in realization of algorithm.The basic expressions of the theory used in the method about internal resistance of the storage battery are considered.The function chart of construction of an analog part of the scheme, and also algorithm of action of the scheme of logic of decision-making are considered.Construction of the tracing generator of load, the important part in realization of the method is stated. The use of the analog machine for processing of the results of measurements and a differential method of measurement with the purpose of increase the accuracy of the method is offered.

Investigation of a Micro PEM Fuel Cell Pack Based on MEMS Technology

Investigation of a micro PEM fuel cell pack based on MEMS technology is carried out in this paper. A Novel type of Z-type anode flow field plates were applied to replace the full pin-type ones used previously and all the single cells were assembled in the same plane with a fuel distributor as their support. The total pack's volume is about 4.0ml. Operating on dry H2 and air-breathing conditions at 20±3°C and 50±3% RH, the pack produced the peak power of 1.34W and the estimated maximum power density of the pack could reach 335W/L. Meanwhile, all the single cells had rather even performances which were based on V-I and internal resistance measurement (EIS). The results suggested that the pack's performance was greatly improved compared to the previous work. The novel Z-type anode flow field leading to more even fuel distribution among each cell probably had the greatest contribution for the improvement.

Remote monitoring of VRLA batteries for telecommunications systems

This paper describes a remote monitoring system that can be set up in an operating center to monitor the state of valve regulated lead acid batteries (VRLA) used as a backup power supply for telecommunications. This system has a battery voltage monitoring function, a lifetime prediction function based on ambient temperature, and a discharge circuit diagnosis function. In addition, the system can be equipped with an internal resistance measurement function and an electrolyte leakage detection function to further insure power-supply reliability. Various states of batteries observed with the system are transmitted to the remote operating center by a remote monitoring function. This function enables obtaining immediate information about the condition of batteries and helps to avoid unexpected failures.

Advanced thermal tester for accurate measurement of internal thermal resistance of high power electronic modules

A thermal tester has been developed for the accurate measurement of the internal thermal resistance of high-power electronic modules. The tester is designed for the simultaneous measurement of 20 electronic modules each dissipating in excess of 200 W. The heat dissipated is transmitted to the ambient by water-cooled cold plates dedicated to each test site. The tester system layout, mounting assembly, hydraulic design, cold-plate spreader design and data acquisition instrumentation are described. Sample measurements and the associated uncertainty are also discussed. The sample results are validated by comparison with thermal modeling.

A method for measurement of internal longitudinal resistance in papillary muscle.

We have modified the original Weidmann method for the measurement of internal longitudinal resistance in ventricular muscle by using air rather than silicon oil to insulate guinea pig papillary muscles and by omitting the tetrodotoxin inactivation of a portion of the preparation and have examined the requirements necessary for the theoretical assumptions to be satisfied by this or similar preparations. We found a homogeneous depolarization wavefront beyond about 1 mm from the stimulating electrodes. The adequacy of the interelectrode spacing was identified by a discrete plateau in the extracellular potential recording. The extracellular resistance in this preparation was sensitive to changes in the volume of the extracellular compartment, which we manipulated by changing inflow and outflow rates, and to changes in total ionic content of the superfusate. Our results establish the essential nature of maintaining constant flow rates and total ionic content and suggest that changes in volume and ionic content of a restricted extracellular space could conceivably influence conduction in vivo.

Instrument for Continuous Measurement of Internal Resistance of Voltaic Cells During Discharge

An instrument for measuring electrolyte conductance or resistance is described. This instrument is unique in that it has the following combination of features: (1) resistance values in the range 1×10−1 to 2×105 Ω can be measured with an accuracy of better than 5%; (2) resistance can be continuously recorded as a function of time; (3) the internal resistance of voltaic cells can be measured during cell discharge; and (4) no special conductivity cells are required. The present instrument is a modified ac Wheatstone bridge. The value of the unbalance signal is monitored and mathematically converted to resistance. Uses for the instrument are discussed and typical results are given.