Journal articles: 'SHORT CIRCUIT LEVELS'

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ALI, Assist Prof Dr Inaam I., and Mohanad Sh Tarad AL-AASAM. "REDUCING SHORT CIRCUIT LEVELS BY USING SYSTEM SPLITTING STRATEGIES." Al-Qadisiyah Journal for Engineering Sciences 11, no. 3 (January 31, 2019): 309–31. http://dx.doi.org/10.30772/qjes.v11i3.563.

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Preliminary studies on Iraqi power system show a significant increase in the short circuit level at some of the grid substations and some power stations. This increasing results from the growth of the power generation and transmission systems in size and complexity. Islanding or splitting is dividing the power system into several islands inorder to reduce short circuit levels and avoiding blackouts. The main islanding problem is determining the location of proper splitting points and load balance and satisfaction of transmission capacity constraints for each islands.This paper mainly introduces new proposed splitting strategies of large-scale power systems by using (PSS™E version 30.3 PACKAGE PROGRAME), such that, make re-interconnection of 400KV super high voltage substation based on three-phase load flow to be minimum flow at splitting point and infeed fault current details method to control short circuit levels in Iraq power system without islanding the power system into isolated islands. Controlled islanding or splitting scheme is frequently considered as the final solution to avoid blackouts of power system.Simulation IEEE-25 bus and Iraqi power system used as the test systems for this method. Furthermore, simulation results show significant effectiveness on reducing short circuit levels with same time give stable splitting islands with same frequency for preventing the system blackouts.

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V., DAVYDENKO, and DAVYDENKO L. "ANALYSIS OF ELECTROMAGNETIC TRANSITIONAL PROCESSES IN THE DISTRIBUTION NETWORK OF 10 KV INDUSTRIAL ENTERPRISE." Journal of Electrical and power engineering 27, no. 2 (November 28, 2022): 10–14. http://dx.doi.org/10.31474/2074-2630-2022-2-10-14.

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The article is devoted to the issue of short-circuit analysis in the high-voltage network of the power supply system of an industrial enterprise. A short-circuit analysis is based on the methodology recommended by the IEC 60909 International Standard. The method of equivalent voltage source at a shortcircuit point was used to calculate a short-circuit current. The necessity to analyze short-circuit currents at all levels of the power supply system was used as justification of the feasibility of automation of the calculation process. Module "Shortcircuit analysis" of the ETAP software was used as an analysis tool. The nominal parameters of the elements of the power supply system of the industrial enterprise and its topological structure are the initial data for the calculation. A single-line scheme of a 10 kV distribution network of power supply system is designed in ETAP program for implementation of the calculation process. The calculation of the value of the initial and maximum current for symmetric (three-phase) and asymmetrical ("phase-phase" and "phase-land") short circuits at the specified points of the electrical network, as well as the detection of inconsistency of characteristics installed equipment to short-circuit currents and displaying inadequate places are the result of the module "Short-circuit analysis" of the ETAP program. The results of the analysis of short circuit in the investigated distribution network of the 10 kV industrial enterprise did not find inconsistencies of the equipment characteristics of the requirements for the stability of short-circuit currents.

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Abbas, Zainab Nadhim, and Firas Mohammed Tuaimah. "Stability Improvement of The Iraqi Super Grid (400kV) using High Voltage Direct Current (HVDC) Transmission." Journal of Engineering 27, no. 11 (November 1, 2021): 64–74. http://dx.doi.org/10.31026/j.eng.2021.11.05.

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This research analyzes the level of the short circuit effect of the Iraqi super network and decides the suitable location for the High Voltage Direct Current (HVDC) connections in order to obtain the best short circuit reduction of the total currents of the buses in the network. The proposed method depends on choosing the transmission lines for Alternating current (AC) system that suffers from high Short Circuit Levels (SCLs) in order to reduce its impact on the transmission system and on the lines adjacent to it and this after replacing the alternating current (AC) line by direct current (DC) line. In this paper, Power System Simulator for Engineering (PSS/E) is used to model two types of HVDC lines in an effective region of Iraqi networks and to perform comparative studies to test the location of Short Circuit Levels (SCLs) between an actual AC and AC/DC case study in a portion of the Iraqi national network. The results proved the effectiveness of this method in eliminating severe faults and unwanted short currents, and the results showed that the bipolar type is better in reducing Short Circuit Levels of the Iraqi network.

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Tomczyk, Marcin, Ryszard Mielnik, Anna Plichta, Iwona Gołdasz, and Maciej Sułowicz. "Application of Genetic Algorithm for Inter-Turn Short Circuit Detection in Stator Winding of Induction Motor." Energies 14, no. 24 (December 17, 2021): 8523. http://dx.doi.org/10.3390/en14248523.

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This paper presents a new method of inter-turn short-circuit detection in cage induction motors. The method is based on experimental data recorded during load changes. Measured signals were analyzed using a genetic algorithm. This algorithm was next used in the diagnostics procedure. The correctness of fault detection was verified during experimental tests for various configurations of inter-turn short-circuits. The tests were run for several relevant diagnostic signals that contain symptoms of faults in an examined cage induction motor. The proposed algorithm of inter-turn short-circuit detection for various levels of winding damage and for various loads of the examined motor allows one to state the usefulness of this diagnostic method in normal industry conditions of motor exploitation.

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Idoniboyeobu, D. C., S. L. Braide, and Wigwe Elsie Chioma. "Fault Assessment and Mitigation of the 132kV Transmission Line in Nigeria using Improved Resonant Fault Current Limiting (RFCL) Protection Scheme." European Journal of Engineering Research and Science 3, no. 10 (October 17, 2018): 38–44. http://dx.doi.org/10.24018/ejers.2018.3.10.796.

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This research work proposed an improved Resonant Fault Current Limiting (RFCL) protection scheme to reduce the impact of three-phase short-circuit faults in a power system sub-transmission network. The model used an interpolator-extrapolator technique based on a Resonant Fault Current Limiter (RFCL) for automating the procedure of predicting the required reactor value that must be in resonant circuit to limit the short-circuit current values to permissible values. Using the developed model, short-circuit fault simulations on the three phases of the transmission line (Phase A-C) were performed in the MATLAB-SIMULINK environment. Simulation results were obtained by varying the resonant inductance (reactor) parameter of the RFCL circuit for each of the phases to obtain permissible short-circuit current levels and the values used to program a functional interpolator-extrapolator in MATLAB; the resonant values were typically set to values of inductance equal to 0.001H, 0.01H and from 0.1H to 0.5H in steps of 0.1H. Simulation results revealed the presence of very high short-circuit current levels at low values of the resonant inductor. From the results of simulations, there are indications that the RFCL approach is indeed very vital in the reduction of the short circuit current values during the fault and can safeguard the circuit breaker mechanism in the examined power system sub-transmission system. In addition, lower fault clearing times can be obtained at higher values of inductances; however, the clearance times start to converge at inductance values of 0.1H and above.

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Idoniboyeobu, D. C., S. L. Braide, and Wigwe Elsie Chioma. "Fault Assessment and Mitigation of the 132kV Transmission Line in Nigeria using Improved Resonant Fault Current Limiting (RFCL) Protection Scheme." European Journal of Engineering and Technology Research 3, no. 10 (October 17, 2018): 38–44. http://dx.doi.org/10.24018/ejeng.2018.3.10.796.

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This research work proposed an improved Resonant Fault Current Limiting (RFCL) protection scheme to reduce the impact of three-phase short-circuit faults in a power system sub-transmission network. The model used an interpolator-extrapolator technique based on a Resonant Fault Current Limiter (RFCL) for automating the procedure of predicting the required reactor value that must be in resonant circuit to limit the short-circuit current values to permissible values. Using the developed model, short-circuit fault simulations on the three phases of the transmission line (Phase A-C) were performed in the MATLAB-SIMULINK environment. Simulation results were obtained by varying the resonant inductance (reactor) parameter of the RFCL circuit for each of the phases to obtain permissible short-circuit current levels and the values used to program a functional interpolator-extrapolator in MATLAB; the resonant values were typically set to values of inductance equal to 0.001H, 0.01H and from 0.1H to 0.5H in steps of 0.1H. Simulation results revealed the presence of very high short-circuit current levels at low values of the resonant inductor. From the results of simulations, there are indications that the RFCL approach is indeed very vital in the reduction of the short circuit current values during the fault and can safeguard the circuit breaker mechanism in the examined power system sub-transmission system. In addition, lower fault clearing times can be obtained at higher values of inductances; however, the clearance times start to converge at inductance values of 0.1H and above.

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Pantielieieva, Iryna, and Alyona Glushko. "Ways to limit the levels of short circuit currents in electrical grids." Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, no. 4(6) (December 31, 2020): 54–59. http://dx.doi.org/10.20998/2413-4295.2020.04.08.

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Romaniuk, F. A., E. V. Buloichyk, and M. A. Shevaldin. "Determination of the Fault Zone by the Level of Short-Circuit Currents." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 61, no. 5 (October 4, 2018): 396–407. http://dx.doi.org/10.21122/1029-7448-2018-61-5-396-407.

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The methods of determination the fault zone according to the parameters of the emergency mode, which can be used to improve the performance of technical perfection of current protection lines of distributive 6–10 kV one-way power networks, are considered. The advantage of the algorithm of determination the zones of short circuit (SC) according to the level of emergency currents as compared to the remote unilateral method addressing the parameters of the damaged loop corrupted loops (loops) is noted. Calculation of the estimated distance to the point of SC on the basis of difference of damaged phase currents has been proposed, that enables the independence of the obtained result on the type of the fault. A technique for increasing the reliability of the method for determination the short-circuit zone by the level of emergency currents based on information about the type of damage has also been proposed. The effect of load currents and contact resistances of different levels on the magnitude and nature of the changes in the errors of the calculated distance to the short circuit was investigated by the method of computational experiment. The levels of contact resistances relative to the total resistance of the line depending on the place of SC occurrence are determined that provides reliable determination of the fault zone; it is demonstrated that the nature of their alteration is approximately the same for lines of medium and long length. The expediency of correction of the calculated distance to the fault location in many cases of short circuits through the contact resistance so to improve the protection capacity of the high-speed current protection stage is demonstrated. Based on the results of the computational experiment, correction factors for the correction of the value of the emergency current have been obtained; on the basis of the latter the fault zone is determined. The estimation of efficiency of the proposed method of correction has been carried out; it is shown that its application makes it possible to improve the accuracy of determination the fault zone and to expand the zone of instantaneous shutdown of short circuit. The dynamic properties of the proposed algorithm for different modes of the line operation have been investigated; it is ascertained that, in the worst case, the determination of the short circuit zone for a time not exceeding 27 ms is provided.

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Berry, Jonathan, Ali Kazerooni, and Michael Eves. "Impact of low-carbon technologies on short-circuit levels in medium voltage networks." CIRED - Open Access Proceedings Journal 2017, no. 1 (October 1, 2017): 2334–37. http://dx.doi.org/10.1049/oap-cired.2017.0738.

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10

Antipov, K. M., A. A. Vostrosablin, V. V. Zhukov, E. P. Kudryavtsev, I. P. Kryuchkov, Yu P. Kuznetsov, K. V. Mozgalev, et al. "The Problem of Coordination of Levels of Short-Circuit Currents in Power Systems." Power Technology and Engineering 39, no. 3 (May 2005): 166–78. http://dx.doi.org/10.1007/s10749-005-0304-6.

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11

Gusev, O. Yu, and A. P. Dolin. "Thermal Stability of Overhead Power Transmission Lines Under Growing Short-Circuit Current Levels." Power Technology and Engineering 52, no. 3 (September 2018): 361–65. http://dx.doi.org/10.1007/s10749-018-0960-y.

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Hikosaka, Okihide, Masaharu Yasuda, Kae Nakamura, Masaki Isoda, Hyoung F. Kim, Yasuo Terao, Hidetoshi Amita, and Kazutaka Maeda. "Multiple neuronal circuits for variable object–action choices based on short- and long-term memories." Proceedings of the National Academy of Sciences 116, no. 52 (December 23, 2019): 26313–20. http://dx.doi.org/10.1073/pnas.1902283116.

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At each time in our life, we choose one or few behaviors, while suppressing many other behaviors. This is the basic mechanism in the basal ganglia, which is done by tonic inhibition and selective disinhibition. Dysfunctions of the basal ganglia then cause 2 types of disorders (difficulty in initiating necessary actions and difficulty in suppressing unnecessary actions) that occur in Parkinson’s disease. The basal ganglia generate such opposite outcomes through parallel circuits: The direct pathway for initiation and indirect pathway for suppression. Importantly, the direct pathway processes good information and the indirect pathway processes bad information, which enables the choice of good behavior and the rejection of bad behavior. This is mainly enabled by dopaminergic inputs to these circuits. However, the value judgment is complex because the world is complex. Sometimes, the value must be based on recent events, thus is based on short-term memories. Or, the value must be based on historical events, thus is based on long-term memories. Such memory-based value judgment is generated by another parallel circuit originating from the caudate head and caudate tail. These circuit-information mechanisms allow other brain areas (e.g., prefrontal cortex) to contribute to decisions by sending information to these basal ganglia circuits. Moreover, the basal ganglia mechanisms (i.e., what to choose) are associated with cerebellum mechanisms (i.e., when to choose). Overall, multiple levels of parallel circuits in and around the basal ganglia are essential for coordinated behaviors. Understanding these circuits is useful for creating clinical treatments of disorders resulting from the failure of these circuits.

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Erhan, Fiodor, and Dinu Voinesco. "Assessing the Influence of Asymmetric Modes on the Reliability Indicators of Distribution Systems." National Interagency Scientific and Technical Collection of Works. Design, Production and Exploitation of Agricultural Machines, no. 51 (2021): 88–94. http://dx.doi.org/10.32515/2414-3820.2021.51.88-94.

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The power electric distribution systems (PEDS) possess a great dynamics of development. Thanks to this phenomenon in the power electric distribution systems (PEDS) the probability of apparatus of asymmetrical regimes increase monotonously. As a result of this reliability of the functioning of the power electric equipment installed in the electric knots changes. The asymmetrical regimes in the power electric distribution systems (PEDS) accompanied by the short circuit current are a function of a row determinate is a vague factor of probabilistic nature. Coming from it follows that the investigation of the influence of the asymmetrical regimes accompanied by the current of the short circuit on the reliability of the Power Electric Distribution Systems (PEDS) is one of the most important problems of the development the Power Electric Distribution Systems. The short circuit currents influence the structural and functional reliability of distribution networks and at the reliability of electrical equipment installation. The dynamics of changes in the levels of short circuit currents in electrical networks depends on the rate of change of the re-recovering voltage at the short circuit point on the power supply side and on the load side, as well as on the magnitude and rate of power change at the short circuit point on the power source side and on the load side.

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Ryan, Michael, Jaime Kaminer, Patricia Enmore, and Craig Evinger. "Trigeminal high-frequency stimulation produces short- and long-term modification of reflex blink gain." Journal of Neurophysiology 111, no. 4 (February 15, 2014): 888–95. http://dx.doi.org/10.1152/jn.00667.2013.

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Reflex blinks provide a model system for investigating motor learning in normal and pathological states. We investigated whether high-frequency stimulation (HFS) of the supraorbital branch of the trigeminal nerve before the R2 blink component (HFS-B) decreases reflex blink gain in alert rats. As with humans (Mao JB, Evinger C. J Neurosci 21: RC151, 2001), HFS-B significantly reduced blink size in the first hour after treatment for rats. Repeated days of HFS-B treatment produced long-term depression of blink circuits. Blink gain decreased exponentially across days, indicating a long-term depression of blink circuits. Additionally, the HFS-B protocol became more effective at depressing blink amplitude across days of treatment. This depression was not habituation, because neither long- nor short-term blink changes occurred when HFS was presented after the R2. To investigate whether gain modifications produced by HFS-B involved cerebellar networks, we trained rats in a delay eyelid conditioning paradigm using HFS-B as the unconditioned stimulus and a tone as the conditioned stimulus. As HFS-B depresses blink circuits and delay conditioning enhances blink circuit activity, occlusion should occur if they share neural networks. Rats acquiring robust eyelid conditioning did not exhibit decreases in blink gain, whereas rats developing low levels of eyelid conditioning exhibited weak, short-term reductions in blink gain. These results suggested that delay eyelid conditioning and long-term HFS-B utilize some of the same cerebellar circuits. The ability of repeated HFS-B treatment to depress trigeminal blink circuit activity long term implied that it may be a useful protocol to reduce hyperexcitable blink circuits that underlie diseases like benign essential blepharospasm.

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Li, Yong Gang, and Bing Han. "Magnetic Field Finite Element Analysis of Generator with Rotor Inter-Turn Short-Circuit Fault." Applied Mechanics and Materials 707 (December 2014): 343–47. http://dx.doi.org/10.4028/www.scientific.net/amm.707.343.

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Rotor inter-turn short-circuit is a common fault in generator and it is a research hotspot to identify the fault at its early stage. Considering the disadvantage of circuit analytical method, this paper establishes a 2D transient finite element electromagnetic-circuit coupling model, and calculates the magnetic field at normal and fault situations through the powerful post-processing function of ANSOFT, then magnetic flux density cloud pictures and air-gap magnetic flux density curves of different operating conditions are got. Using MATLAB to analyze and deal with the air-gap flux density cures, we can get the differences of faults in different levels and different positions, which provide a basis for further study of rotor inter-turn short-circuit fault.

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Saldarriaga-Zuluaga, Sergio D., Jesús M. López-Lezama, Carlos David Zuluaga Ríos, and Alejandro Villa Jaramillo. "Effects of the Incorporation of Electric Vehicles on Protection Coordination in Microgrids." World Electric Vehicle Journal 13, no. 9 (August 29, 2022): 163. http://dx.doi.org/10.3390/wevj13090163.

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Amid growing concerns about climate change, electricity-powered transportation systems stand out as an opportunity to help in reducing fuel consumption. Electric vehicles (EVs) would connect to the grid using clean, renewable electricity; however, the interconnection between EVs and the grid brings about new challenges for traditional power systems. Plug-in hybrid EVs and plug-in EVs have started to become more prevalent in the system; therefore, their impacts and benefits are also of concern. Among these concerns is the detailed analysis of the impact that EVs may have on short-circuit levels in microgrid protection schemes. In this context, the main contribution of this paper is a detailed evaluation of the impact of EVs on the short-circuit levels and protection coordination schemes in microgrids. For this purpose, a methodology was proposed to measure the impact of EVs on the protection coordination schemes in microgrids using different evaluation indices. The proposed approach was validated on a benchmark IEC microgrid considering different operative scenarios that envisage several levels of EVs penetration. The results evidenced the applicability of the proposed approach and allows to conclude that the incorporation of EVs in microgids impacts the performance of the protection schemes, specifically with respect to short-circuit levels.

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Lüscher, Christian, and Patricia H. Janak. "Consolidating the Circuit Model for Addiction." Annual Review of Neuroscience 44, no. 1 (July 8, 2021): 173–95. http://dx.doi.org/10.1146/annurev-neuro-092920-123905.

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Addiction is a disease characterized by compulsive drug seeking and consumption observed in 20–30% of users. An addicted individual will favor drug reward over natural rewards, despite major negative consequences. Mechanistic research on rodents modeling core components of the disease has identified altered synaptic transmission as the functional substrate of pathological behavior. While the initial version of a circuit model for addiction focused on early drug adaptive behaviors observed in all individuals, it fell short of accounting for the stochastic nature of the transition to compulsion. The model builds on the initial pharmacological effect common to all addictive drugs—an increase in dopamine levels in the mesolimbic system. Here, we consolidate this early model by integrating circuits underlying compulsion and negative reinforcement. We discuss the genetic and epigenetic correlates of individual vulnerability. Many recent data converge on a gain-of-function explanation for circuit remodeling, revealing blueprints for novel addiction therapies.

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Esmaili, Masoud, Mohammad Ghamsari-Yazdel, Nima Amjady, and Antonio J. Conejo. "Short-Circuit Constrained Power System Expansion Planning Considering Bundling and Voltage Levels of Lines." IEEE Transactions on Power Systems 35, no. 1 (January 2020): 584–93. http://dx.doi.org/10.1109/tpwrs.2019.2926410.

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Fan, Chunju, Kan Xu, and Qi Liu. "Short-circuit current calculation method for partial coupling transmission lines under different voltage levels." International Journal of Electrical Power & Energy Systems 78 (June 2016): 647–54. http://dx.doi.org/10.1016/j.ijepes.2015.12.007.

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Zhang, Yuhong, Yantao Zhang, Jiahui Han, Xueqiong Wang, Qiyu Chen, and Jian Zhang. "The adaptability of IEC 60909: 0-2016 to power grid with voltage levels above 400kV." Journal of Physics: Conference Series 2276, no. 1 (May 1, 2022): 012018. http://dx.doi.org/10.1088/1742-6596/2276/1/012018.

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Abstract The equivalent voltage source method is recommended in IEC 60909 for short-circuit current calculation, and the accuracy is verified by 400 kV and below voltage level power grids. There are 500 kV, 750 kV or 1000 kV power grids in some countries where IEC standards are applied, but there is no relevant research to verify the accuracy of the calculation method. In this paper, verification methods for IEC 60909 calculation accuracy for the three voltage level power grids are adopted. Calculation examples based on the operation and equipment parameters of the 500 kV, 750 kV and 1000 kV power grids are established. The results show that IEC 60909 short-circuit current calculation method is conservative, and the calculation accuracy meets the requirements. The research expands the application scope of this standard to all AC power grids, which is conducive to the engineering application of IEC 60909.

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Sturm, J., S. Friedrich, S. Genies, D. Buzon, Rahn-Koltermann G., A. Rheinfeld, and Jossen A. "Experimental Analysis of Short-Circuit Scenarios Applied to Silicon-Graphite/Nickel-Rich Lithium-Ion Batteries." Journal of The Electrochemical Society 169, no. 2 (February 1, 2022): 020569. http://dx.doi.org/10.1149/1945-7111/ac51f3.

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Short-circuit incidents pose a severe safety threat to lithium-ion batteries during lifetime. Understanding the underlying electrochemical behavior can help to mitigate safety risks. The electrochemically-caused rate-limiting behavior is analyzed using a quasi-isothermal test-bench, where external and local short-circuit conditions are applied to single-layered pouch cells (<50 mAh). The cell voltage, the heat generation rate, and either the short-circuit current or a local electrical potential are measured and used to characterize the short-circuit intensity. The results of 35 custom-built silicon-graphite SiC/NCA and SiC/NMC-811 cells with 2.5 wt.-% silicon are benchmarked to previously studied graphite G/NMC-111 cells. An additional current plateau appears for the silicon-graphite/nickel-rich cells, which is ascribed to the anode-limited electrode balancing. At a maximum, 29% of the total dissipated heat is caused during over-discharge. The effect of cyclic aging on the impact of the short-circuit behavior is investigated with aged single-layered pouch cells (SoH < 80%), which revealed nearly the same levels of over-discharge as non-aged cells. A lithium reference electrode is used to visualize polarization effects in the anode during ESCs and to evaluate the onset of copper dissolution (>3.2 V vs Li/Li+), which could be estimated up to 20% of the negative current collector mass.

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Dang, Dongfeng, Pei Zhou, Linrui Duan, Xichang Bao, Renqiang Yang, and Weiguo Zhu. "An efficient method to achieve a balanced open circuit voltage and short circuit current density in polymer solar cells." Journal of Materials Chemistry A 4, no. 21 (2016): 8291–97. http://dx.doi.org/10.1039/c6ta02298g.

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Good light harvesting properties and matched energy levels as well as enhanced J_sc value and high V_oc value in solar cells were achieved simultaneously by construction of the D–A–π–A type regular terpolymers of PIDT-DTQ-TT, finally leading to the maximum PCE value of 6.63% in PSCs.

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Yan, Mu-Tian, and Pai-Hung Hsieh. "Monitoring and Adaptive Process Control of Wire Electrical Discharge Turning." International Journal of Automation Technology 8, no. 3 (May 5, 2014): 468–77. http://dx.doi.org/10.20965/ijat.2014.p0468.

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This paper presents a novel pulse discriminating and control system for the identification of spark gap states, process monitoring and control of Wire Electrical Discharge Turning (WEDT). The relation between the proportion of open circuit, normal spark, arc discharge, short circuit to total sparks (defined as open circuit ratio, normal spark ratio, arc discharge ratio and short circuit ratio, respectively), ignition delay time and metal removal rate were experimentally studied and analyzed. A fuzzy logic controller was proposed to control both the arc discharge ratio and ignition delay time at optimal levels by on-line regulation of table feed-rate and pulse off-time for adaptive control optimization of WEDT. Experimental results show that the developed process monitoring and control system results in faster machining and better machining stability as compared with a conventional servo feed control scheme for the WEDT process.

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Li, Yong Gang, Guo Wei Zhou, Yu Ca Wu, and He Ming Li. "Impact of Rotor Inter-Turn Short-Circuit on Generator Rotor Force." Applied Mechanics and Materials 143-144 (December 2011): 125–31. http://dx.doi.org/10.4028/www.scientific.net/amm.143-144.125.

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This paper analyzes the calculation method of unbalanced electromagnetic force by rotor winding inter-turn short-circuit fault, analytical calculating method neglects saturation, cogging and other factors, so the calculation accuracy is not high, in order to accurately calculate the magnetic field and the unbalanced electromagnetic force, this paper propose to analyze generator magnetic field by a finite element software Ansys, the obtained magnetic field data are further used to analyze the distributed electromagnetic force and the total force that generator rotor suffered, electromagnetic force distribution law of different slots, different levels of inter-turn short-circuit are got, which provide a basis for further studying the full force on generator rotor.

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Shivari, Rishi, and Natalie Banerji. "Photophysics and Charge Generation in Low Energy-offset Blends for Organic Solar Cells." CHIMIA 75, no. 10 (October 11, 2021): 862. http://dx.doi.org/10.2533/chimia.2021.862.

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The power conversion efficiency of organic solar cells has seen a huge improvement in recent years with state-of-the-art solar cells showcasing efficiencies of ~18.5 %, which is approaching the performance of inorganic and hybrid-perovskite solar cell technologies. This improvement can be mainly attributed to the discovery of highly efficient donor:acceptor blends with a near-zero energetic offset between the molecular orbital levels of the donor and the acceptor component. A distinctive feature of the high efficiency, low energy-offset blends is that they exhibit a concomitant increase in the short-circuit density and the open-circuit voltage of the solar cell. High open-circuit voltage results from the reduced photon energy loss in the exciton dissociation step, while a high short-circuit current density can be attributed to an efficient charge generation process. The reasons for the efficient exciton dissociation and subsequent separation of Coulomb bound electron-hole pair at negligible driving force is not well understood and, in this short review, we highlight recent results which shed light on the mechanism of charge generation in low energy-offset blends.

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Osintsev, Anatoly A., Aleksandra I. Naumova, and Elena I. Gracheva. "Analysis of distance protection’s operation in cases of deep saturation of current transformers." E3S Web of Conferences 288 (2021): 01095. http://dx.doi.org/10.1051/e3sconf/202128801095.

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There is usually no information about permissible error of current transformers in modes succeed by large relative short-circuit current, at which microprocessor-based protections operate stably. By this reason, it is necessary to use data, defined for analog relays. It leads to value appreciation of a project because it is often essential to reduce current transformers’ error in case of a short circuit fault. Therefore, it is necessary to define the value of current transformers’ error, permitted for impedance relays. Conclusions of fundamental and applied sciences (mathematical analysis, theoretical foundations of electrical engineering, theory of simulation), analytical methods of researching nonlinear circuits and digital signal processing were used. A simulation model was created for setting overall tests of the current trans-former (CT) system. It was a relay protection device that reflected all the important properties of studied objects and allowed an analysis of digital distance protection’s operation at high levels of short-circuit currents. The factors influ-encing over digital distance protection’s operation in case of deep saturation of CTs were revealed, and a certain algorithm for definition of the permissible CT errors was proposed. Stable operation of digital distance protection was observed in case of a fault nearby the place of current transformers’ setting in all theoretically possible combinations of electrical system’s power and length of a protected electric power transmission line. It is valid if electric load choice is carried with account for stable protection’s operation in condition of a fault in the computational point and if voltage swell in secondary wirings is infeasible.

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Jia, Yikai, and Jun Xu. "Machine Learning Lithium-Ion Battery Safety Risk Level Classification." ECS Meeting Abstracts MA2022-02, no. 26 (October 9, 2022): 1015. http://dx.doi.org/10.1149/ma2022-02261015mtgabs.

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Due to inevitable external mechanical abusive loadings, lithium-ion batteries (LIB) will suffer damages or defects. If the safety risk level of the cell is unknown, an early decision cannot be made. In this work, we develop a Random Forest (RF) based classification model to implement online safety risk level classification with low time cost and high accuracy. Four levels of battery cell safety risk are defined: a). Normal; b), Latent risk (defective cells, short circuit but normal operation); c). Low risk (short circuit without possible TR triggering); d). High risk (short circuit with possible TR triggering). The training dataset combines experimental data and simulation data from the multi-physical model. The training samples consist of voltage, current, and temperature signals under different operating conditions and different risk level scenarios. The prediction results show that the classifiers have a good performance and robustness. This approach will provide insight into the identification, monitoring, and early warning of battery safety issues.

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Zuo, Liang, S. K. Islam, M. A. Huque, C. Su, B. J. Blalock, and L. M. Tolbert. "A Universal BCD-on-SOI Based High Temperature Short Circuit Protection for SiC Power Switches." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2010, HITEC (January 1, 2010): 000349–54. http://dx.doi.org/10.4071/hitec-lzuo-tha15.

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In recent years, the rapid increase in the market for hybrid electric vehicles has generated great demand for low-cost, high-volume, high-temperature power converters that can work in harsh environment (temperature ≥ 150°C) conditions. Most of the commercially available power semiconductor devices and associated control electronics are rated for maximum of 85°C ambient temperature. Under this circumstance, wide bandgap (WBG) semiconductors have become a better alternative due to their ability to operate at much higher temperatures (≥500°C) than conventional bulk silicon based devices. As with any other power devices, SiC switches also require fault detection and protection mechanisms for their reliable application to real systems. One severe fault situation is the short circuit at the load end, which can cause very high surge currents that flow through the power switches. Quick detection and removal of the short circuit fault current by external circuitry is required to protect the power switch as well as the power converter module. This work presents a high-temperature (≥200°C), high-voltage short circuit protection (SCP) for SiC power devices. The circuit is designed using a resistor sensing method to provide protections for both “normally ON” and “normally OFF” SiC FET switches. A rail-to-rail input comparator is employed to ensure that the circuit operates under different power supply levels. The prototype circuit is implemented using a 0.8-micron, 2-poly, and 3-metal BCD-on-SOI process. The die size for the protection circuit is 0.52 mm2 (845 μm × 612 μm). The circuit has been successfully tested up to 200°C ambient temperature under power supplies ranging from 10 V to 30 V without any heat sink or cooling mechanism.

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Saponara, Sergio, Filippo Giannetti, and Bruno Neri. "Design Exploration of mm-Wave Integrated Transceivers for Short-Range Mobile Communications Towards 5G." Journal of Circuits, Systems and Computers 26, no. 04 (December 6, 2016): 1750069. http://dx.doi.org/10.1142/s0218126617500694.

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This paper presents a design exploration, at both system and circuit levels, of integrated transceivers for the upcoming fifth generation (5G) of wireless communications. First, a system level model for 5G communications is carried out to derive transceiver design specifications. Being 5G still in pre-standardization phase, a few currently used standards (ECMA-387, IEEE 802.15.3c, and LTE-A) are taken into account as the reference for the signal format. Following a top-down flow, this work presents the design in 65[Formula: see text]nm CMOS SOI and bulk technologies of the key blocks of a fully integrated transceiver: low noise amplifier (LNA), power amplifier (PA) and on-chip antenna. Different circuit topologies are presented and compared allowing for different trade-offs between gain, power consumption, noise figure, output power, linearity, integration cost and link performance. The best configuration of antenna and LNA co-design results in a peak gain higher than 27[Formula: see text]dB, a noise figure below 5[Formula: see text]dB and a power consumption of 35[Formula: see text]mW. A linear PA design is presented to face the high Peak to Average Power Ratio (PAPR) of multi-carrier transmissions envisaged for 5G, featuring a 1[Formula: see text]dB compression point output power (OP1dB) of 8.2[Formula: see text]dBm. The delivered output power in the linear region can be increased up to 13.2[Formula: see text]dBm by combining four basic PA blocks through a Wilkinson power combiner/divider circuit. The proposed circuits are shown to enable future 5G connections, operating in a mm-wave spectrum range (spanning 9[Formula: see text]GHz, from 57[Formula: see text]GHz to 66[Formula: see text]GHz), with a data-rate of several Gb/s in a short-range scenario, spanning from few centimeters to tens of meters.

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Romaniuk, F. A., E. V. Buloichik, O. A. Huryanchyk, and M. A. Shevaldin. "DETERMINING A TYPE OF A DAMAGE IN THE CURRENT PROTECTION OF POWER LINES OF 6–35 KV." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 60, no. 6 (November 23, 2017): 497–504. http://dx.doi.org/10.21122/1029-7448-2017-60-6-497-504.

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The methods to identify types of phase-to-phase short circuits that can be used to improve technical excellence by speed-current line protection of distribution networks of 6–35 kV are considered. As a result of the assessment of the appropriateness of their application in current protection, the choice was made in favor of the method based on the control of the relative current unbalance. The influence of contact resistances and load currents of various levels on the magnitude and character of the change of relative unbalance taking into account the errors of measuring transformers of current has been studied with the aid of the method of numerical experiment. It is demonstrated that in a lot of cases of arch short circuits in the loaded power line and in idle mode, the control only asymmetry is insufficient for reliable determination of the type of damage. A better algorithm has been proposed for determining phase-to-phase short circuit based on the control and the analysis of the two relative unbalance currents determined by the current values of the differences of the phase currents of the line. Its serviceability was evaluated. It was found out that in all the modes being considered, the proposed method – when boundary conditions are properly chosen – makes it possible to fix three-phase and two-phase short circuit on the protected line, and in the area of remote redundancy. The dynamic properties of the proposed method are investigated for different modes of the line. It is established that in the worst case, the determining of the damage is provided during the time not exceeding 25 ms.

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MAZILU, Loreta Daniela, Daniel Tudor COTFAS, Petru Adrian COTFAS, and Ecaterina Liliana MIRON*. "THE STUDY OF THE THERMOELECTRIC GENERATOR DEPENDING ON THE LIGHTING LEVELS." SCIENTIFIC RESEARCH AND EDUCATION IN THE AIR FORCE 24 (July 28, 2023): 24–30. http://dx.doi.org/10.19062/2247-3173.2023.24.3.

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Whereas in the 20th century, scientists were concerned with the production of energy in huge quantities, regardless of the consequences, their interest later switched to the production of green energy from renewable sources. Nowadays, the interest has been directed towards increasing the efficiency of existent energy systems and finding other energy sources. A way to achieve these is to harvest energy from sources that generate small amounts of energy, but sufficient to power low-power devices, as well as to valorize residual energy (especially heat) that would otherwise be dissipated and lost. Since thermoelectric generators convert heat into electrical energy based on the Seebeck effect, this paper analyzes the important parameters of the TEC1-12706 thermoelectric generator, such as short circuit current, open circuit voltage, maximum power, and internal resistance in laboratory and natural conditions in function of different levels of irradiance. The performance of the thermoelectric generator is lower in real condition than under artificial light.

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LIU, GAOMIN, FUPING ZHANG, JINMEI DU, HUA TAN, and HONGLIANG HE. "PHASE TRANSITION AND CURRENT PROPERTIES OF PZT 95/5-2NB FERROELECTRIC CERAMIC UNDER DYNAMIC LOADING." International Journal of Modern Physics B 22, no. 09n11 (April 30, 2008): 1171–76. http://dx.doi.org/10.1142/s0217979208046499.

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The high density ferroelectric ceramic with composition near Pb 0.99( Zr 0.95 Ti 0.05)0.98 Nb 0.02 O 3 ( PZT 95/5-2 Nb ) has been studied under dynamic loading. To characterize its ferroelectric-to-antiferroelectric(FE/AFE) phase transition under shock wave compression, reverse-impact experiments were conducted to determine the Hugoniot states of poled and unpoled PZT 95/5-2 Nb , and the shock-induced depoling currents were examined in an external circuit under short-circuit conditions for the poled PZT 95/5-2 Nb . The Hugoniot data and current results identify that the phase transition of FE/AFE has occured in the stress range of 0.4 GPa~1.8 GPa. In the phase transition stress range, the measured short-circuit currents show the increasing of rise time and the decreasing of final levels with the increase of shock stress.

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CHAMBERLIN, M. E. "Ion Transport Across the Midgut of the Tobacco Hornworm (Manduca Sexta)." Journal of Experimental Biology 150, no. 1 (May 1, 1990): 425–42. http://dx.doi.org/10.1242/jeb.150.1.425.

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1. The transport of K+, Na+ and Cl− across the three morphologically distinct regions of the tobacco hornworm midgut was measured under open-circuit and short-circuit conditions. Using a saline which contained physiological levels of haemolymph ions, amino acids and sugars, it was shown that all three sections actively secrete K+ and Cl− and absorb Na+. 2. The anterior section maintained the highest short-circuit current (Isc), transepithelial potential difference (PD) and net K+ secretion. The middle section had the lowest Isc, PD and K+ secretion, but absorbed Na+ at the greatest rate. The posterior section had the greatest rate of Cl− secretion. 3. Omission of K+ depressed the Isc. Subsequent addition of K+ stimulated the Isc to control levels in the middle and posterior sections, but not in the anterior section. Omission of Cl− or Na+ also inhibited the Isc. Reintroduction of Cl− had no stimulatory effect and, although reintroduction of Na+ stimulated the Isc, control levels were not attained. 4. Unlike the results reported in previous studies, the net K+ transport exceeded the Isc in all three midgut sections. The deficit in Isc was not made up by the transport of Na+ and Cl−. The results are discussed with respect to proposed models of ion transport across this epithelium.

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Grubb, B. R., and P. J. Bentley. "Aldosterone-induced, amiloride-inhibitable short-circuit current in the avian ileum." American Journal of Physiology-Gastrointestinal and Liver Physiology 253, no. 2 (August 1, 1987): G211—G216. http://dx.doi.org/10.1152/ajpgi.1987.253.2.g211.

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Transmural electrical potential difference, short-circuit current (Isc), and resistance were measured in vitro in the intestines of chickens. In birds maintained on a low-Na diet, there was a rise in Isc in the ileum and the colon but not in the duodenum or jejunum. A substantial portion of this Isc could be inhibited by the Na channel-blocking drug, amiloride. The low-Na diet results in elevated plasma levels of aldosterone and the effects of the diet on intestinal transport could be mimicked by administration of this hormone. The time course of the effects of these two treatments on the ileum and colon were quite different, as a much longer exposure was needed to elicit maximal effects in the ileum than in the colon, possibly due to the presence of two types of adaptation mechanisms. The responses observed may reflect an adaptation of mechanisms for increasing Na transport from the intestine. The presence of such a mechanism in the vertebrate ileum has until recently been in doubt.

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Vargas, Murillo Cobe, Oureste Elias Batista, and Yongheng Yang. "Estimation Method of Short-Circuit Current Contribution of Inverter-Based Resources for Symmetrical Faults." Energies 16, no. 7 (March 30, 2023): 3130. http://dx.doi.org/10.3390/en16073130.

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This paper proposes a practical approach to estimate the symmetrical short-circuit current (SCC) levels in overcurrent protection devices (OCPDs) installed on radial feeders for any penetration level of inverter-based distributed energy resources (DERs). The proposed method restores the lost phase protection coordination by estimating SCC values and changing the TMS of OCPDs accordingly. The method is validated by comparing the results with simulations on the IEEE 34-Node Test Feeder using MATLAB/Simulink, which shows an average error of 1.5% and a maximum error of 3.0%. For a 100% penetration level, the SCC variation through OCPDs installed on the main fault trunk (MFT) exceeds ± 10%, leading to compromised phase protection coordination. The SCC flowing reversely through OCPDs on lateral branches and the fault on the MFT could cause improper tripping. Higher SCC levels are estimated and measured for fault impedances equal to zero. The phase protection is restored by changing the TMS of OCPDs using the estimated values. The study proposes two phase protection schemes to accommodate inverter-based DERs injecting 1.2 pu and 2.0 pu of SCC for a 100% penetration level. This study contributes to improving the protection coordination of distribution networks with high penetration levels of DERs. The findings have practical implications for distribution system operators and planners to maintain safe and reliable operation of distribution feeders.

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Mobarak, Youssef Ahmed, and Mahmoud M. Hussein. "Voltage Instability of Initiation Fault Duration as Influenced by Nodes Short Circuit Levels NSCL with Different Types of Loads." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 3 (June 1, 2016): 1305. http://dx.doi.org/10.11591/ijece.v6i3.10163.

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The occurrence of voltage instabilities or voltage collapses depend on the duration of the persistence of the fault and on the type of fault, some faults lead to voltage instabilities, others lead to voltage collapse. Evaluation of fault durations causing occurrence of voltage instabilities is the main goal of this paper. This paper searches for the effect of nodes short circuit levels NSCL and its duration periods initiation of voltage instability, with lagging and leading load power factors at certain loads buses. In this paper, the power system dynamic simulation program is developed for dynamic analysis of voltage stability. This paper is concerned with the fault duration which lead to the occurrence of voltage instability phenomena due to NSCL. The fault which lead to voltage instability is found to be short circuits at certain nodes cleared without any variation in the transmission system elements, i.e. the post-fault conditions will be the same as the pre-fault conditions. Models for loads considered in this study are induction motors with three different shaft mechanical loads, constant impedance CZ loads, constant current CI loads and constant power CP loads are used, as they depict the behavior of most power system loads. The influence of the transmission network impedances, which are nearly the inverse of the NSCL, on the fault duration which lead to the occurrence of voltage instabilities are studied and evaluated using various load representations.

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Mobarak, Youssef Ahmed, and Mahmoud M. Hussein. "Voltage Instability of Initiation Fault Duration as Influenced by Nodes Short Circuit Levels NSCL with Different Types of Loads." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 3 (June 1, 2016): 1305. http://dx.doi.org/10.11591/ijece.v6i3.pp1305-1318.

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The occurrence of voltage instabilities or voltage collapses depend on the duration of the persistence of the fault and on the type of fault, some faults lead to voltage instabilities, others lead to voltage collapse. Evaluation of fault durations causing occurrence of voltage instabilities is the main goal of this paper. This paper searches for the effect of nodes short circuit levels NSCL and its duration periods initiation of voltage instability, with lagging and leading load power factors at certain loads buses. In this paper, the power system dynamic simulation program is developed for dynamic analysis of voltage stability. This paper is concerned with the fault duration which lead to the occurrence of voltage instability phenomena due to NSCL. The fault which lead to voltage instability is found to be short circuits at certain nodes cleared without any variation in the transmission system elements, i.e. the post-fault conditions will be the same as the pre-fault conditions. Models for loads considered in this study are induction motors with three different shaft mechanical loads, constant impedance CZ loads, constant current CI loads and constant power CP loads are used, as they depict the behavior of most power system loads. The influence of the transmission network impedances, which are nearly the inverse of the NSCL, on the fault duration which lead to the occurrence of voltage instabilities are studied and evaluated using various load representations.

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Esmaili, Masoud, Mohammad Ghamsari-Yazdel, Nima Amjady, and C. Y. Chung. "Optimal placement of resistive/inductive SFCLs considering short-circuit levels using complex artificial bee colony algorithm." IET Generation, Transmission & Distribution 13, no. 24 (December 17, 2019): 5561–68. http://dx.doi.org/10.1049/iet-gtd.2019.0232.

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Wang, Xiaosha, Honggang Chen, Jun Yuan, Qingya Wei, Jing Li, Lihui Jiang, Jun Huang, Yongfang Li, Yungui Li, and Yingping Zou. "Precise fluorination of polymeric donors towards efficient non-fullerene organic solar cells with balanced open circuit voltage, short circuit current and fill factor." Journal of Materials Chemistry A 9, no. 26 (2021): 14752–57. http://dx.doi.org/10.1039/d1ta01500a.

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By increasing the fluorination sites of polymer donors, the J_SC, V_OC and FF are enhanced for solar cells, because of fine-tuned energy levels, reduced trap-assisted or bimolecular recombination, and improved charge carrier mobility.

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Tang, Bi Qiang, Li Wen Wang, Yi Jun Yu, Fei Shi, and Shu Hai Feng. "A Method of Online Topology Adjustment Decision Support for Short-Circuit Current Limitation." Advanced Materials Research 805-806 (September 2013): 756–62. http://dx.doi.org/10.4028/www.scientific.net/amr.805-806.756.

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With the growing scale of power systems in China, short-circuit current levels of power systems have been significantly increasing. Appropriate grid topology adjustment is an effective method for short-circuit current limitation. The specific measures include transmission line outage, transformer outage, etc. In this paper, a practical optimization algorithm of grid topology adjustment is put forward. A weighted comprehensive sensitivity index is adopted to speed up the procedure of adjustment strategy searching. The detailed calculation method of this index for different measure types is presented. And a security & economy assessment is implemented to ensure the feasibility of potential adjustment strategies. Moreover, the framework of an online topology adjustment decision support software based on this optimization algorithm is proposed. The effectiveness of the presented method is demonstrated by the test on a large-scale power system.

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Phipps, R. J., P. J. Torrealba, I. T. Lauredo, S. M. Denas, M. W. Sielczak, A. Ahmed, W. M. Abraham, and A. Wanner. "Bacterial pneumonia stimulates macromolecule secretion and ion and water fluxes in sheep trachea." Journal of Applied Physiology 62, no. 6 (June 1, 1987): 2388–97. http://dx.doi.org/10.1152/jappl.1987.62.6.2388.

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In vivo instillation of Pasteurella haemolytica (greater than or equal to 10(7) colony-forming units/kg) into a lobar bronchus of sheep produced bacterial pneumonia by 7 days postinoculation. Infection was verified bacteriologically and histologically. Macromolecule secretion and ion and water fluxes were subsequently measured in tracheal tissues in vitro and were compared with values from sham-infected sheep. Macromolecules were radiolabeled with 35SO4 and [3H]threonine, and we measured the secretion of macromolecule-bound radiolabel onto the mucosa. Unidirectional fluxes of Cl-, Na+, and water were measured with radioactive tracers under open-circuit and short-circuit conditions. Lung infection increased basal secretion of bound 35SO4 (by 189%) and bound [3H]-threonine (by 110%). It significantly increased net Na+ absorption under open- and short-circuit conditions and induced open-circuit net absorption of Cl- and water (16 +/- 29 microliters X cm-2 X h-1). These changes were associated with specific recruitment of neutrophils and elevated levels of arachidonate metabolites (thromboxane B2 and leukotriene B4) in the airways. Thus the bacterial pneumonia-induced changes in tracheal mucus secretion may be the result of airway inflammation.

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Rosety-Rodriguez, M., M. Bernardi, S. Elosegui, I. Rosety, A. J. Diaz, M. A. Rosety, F. Brenes, A. Oliva-Pascual-Vaca, J. R. Alvero-Cruz, and F. J. Ordonez. "A Short-Term Resistance Training Circuit Improved Antioxidants in Sedentary Adults with Down Syndrome." Oxidative Medicine and Cellular Longevity 2021 (January 20, 2021): 1–6. http://dx.doi.org/10.1155/2021/8811153.

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Previous studies have found aerobic training improved oxidative damage in people with Down syndrome (DS). However, there is a lack of information regarding the influence of resistance training on redox imbalance in this population. Accordingly, this study was conducted to determine the effect of resistance training (RT) on antioxidant defence system in sedentary adults with DS. Thirty-six male adults with DS were recruited through different community support groups. Eighteen were randomly assigned to perform a circuit RT program with 6 stations, 3 days/week for 12 weeks. Plasma total antioxidant status (TAS), reduced glutathione (GHS), ascorbate, serum α-tocopherol, and erythrocyte glutathione reductase activity were assessed. Plasma malondialdehyde (MDA) and carbonyl groups (CG) were assessed as markers of oxidative damage. Muscle strength was also measured. Dynamic torque of knee extensors and flexors as well as maximal handgrip strength was significantly improved after the completion of the training program. Plasma levels of TAS and erythrocyte glutathione reductase (GR) activity were significantly increased. Conversely, MDA and CG levels were significantly reduced. It was concluded RT improved antioxidant defence system and reduced oxidative damage in adults with DS. Further, long-term studies are required to determine whether the increased antioxidant system may improve clinical outcomes of adults with DS.

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Davud Mostafa Tobnaghi. "Investigation of the changes in the electrical parameters of solar panels with the passage of operation time." Global Journal of Engineering and Technology Advances 15, no. 3 (June 30, 2023): 062–66. http://dx.doi.org/10.30574/gjeta.2023.15.3.0099.

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After several years of using solar cells, its electrical parameters are degraded. in this paper, to simulate of aging, solar cells were exposed to the different doses of gamma radiation. The (I–V) characteristics of silicon solar cells were studied before and after gamma irradiation. Experimental results showed that the electrical parameter of solar panel such as short circuit current, open circuit voltage, and efficiency decrease with the increase of the gamma doses. As well as, dependence of Voc and Isc according to the absorbed dose for different illumination levels has been investigated.

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Song, Xu Ri, Lei Wang, Lin Ye, Yu Zou, Jie Xu, and Cheng Long Dou. "Analysis of Short-Circuit Calculation in Microgrid with Wind/Solar Micro-Sources Based on IEC STANDARD 60909." Advanced Materials Research 1008-1009 (August 2014): 155–59. http://dx.doi.org/10.4028/www.scientific.net/amr.1008-1009.155.

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Microgrid are LV or MV electric networks which utilize various distributed generators (DG) to serve local loads.In this paper an equivalent model of a hybrid system including wind power and solar power generating units has been built based on the mathematical models of wind turbine(WT) and photovoltaic(PV).Control strategies of the converters have been also developed. The short-circuit current and voltage levels of the microgrid have been calculated respectively based on the IEC 60909 standard corresponding to the occurrence of a three-phases short-circuit at the Point of the Common Coupling(PCC). Simulation results verified that the micro sources and microgrid built in this paper can simulate the actual system operation very well, and it can provide a simulation platform for further study of operation characteristics of system-integrated microgrid.

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Romaniuk, F. А., E. V. Buloichyk, O. A. Huryanchyk, and V. S. Kachenya. "THE RELIABILITY OF DETERMINING THE SHORT CIRCUIT ZONE OF THE LINES OF 6–35 kV." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 61, no. 1 (January 23, 2018): 5–14. http://dx.doi.org/10.21122/1029-7448-2018-61-1-5-14.

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A method of increasing the reliability of determining the zone of short-circuit at the current step protection of the lines of 6–35 kV with unilateral power, aimed at improvement of their technical perfection, is presented in the paper. Having taken the relative simpleness of the current protection into account the authors consider the unilateral remote method of accounting the parameters of the emergency mode and the type of fault to be the most suitable for the implementation of the algorithm of its functioning as compared with the existing methods of fault location. The major factors affecting the accuracy of determining the short circuit zone based on the remote method are noted. With the use of the method of computational experiment the influence of the load currents and contact resistances of various levels on the magnitude and character of changes of errors of determination of the calculated distance of the point of fault from the protection installation location taking into account the errors of measuring transformers. It is demonstrated that in many cases of arc short circuit in a loaded line in order to define the zone of short-circuit with fair accuracy correction of the estimated distance to the fault as calculated by the parameters of the damaged loop (loops) is required. According to the results of numerical experiments corrective expressions on the basis of two relative asymmetry currents determined by the current values of the differences of the phase currents of the line for detecting a type of a short circuit have been obtained. The assessment of the efficiency of the proposed method has been performed. It is shown that the application of the proposed correction method makes it possible to increase the accuracy of fault zone detection. The dynamic properties of the proposed method applied to different modes of the line functioning have been studied. It is determined that in the worst case the definition of the fault zone for a maximum duration of 26 μsec is provided.

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Ubar, Raimund. "Overview about low-level and high-level decision diagrams for diagnostic modeling of digital systems." Facta universitatis - series: Electronics and Energetics 24, no. 3 (2011): 303–24. http://dx.doi.org/10.2298/fuee1103303u.

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BDDs have become the state-of-the-art data structure in VLSI CAD. In this paper, a special class of BDDs is presented called Structurally Synthesized BDDs (SSBDD). The idea of SSBDDs is to establish one-to-one mapping between the nodes of SSBDDs and signal paths in the related digital circuit. Such a mapping allowed to investigate and solve with SSBDDs a lot of test and diagnosis related problems of digital circuits, which are associated explicitly with the structure. Such problems are, for example, direct representation of faults, fault collapsing and fault masking, delay testing, hazard detection, etc. The main concept of using SSBDDs is laying on the topological view on the graphs, where each path on a SSBDD can be mapped directly to a subcircuit of the related circuit. Such a topological view allowed to generalize the knowledge and methods of test synthesis and fault analysis from the Boolean level to higher register-transfer and behavior levels of digital systems by introducing High-Level DDs (HLDD). The paper gives a short historical overview of the development of SSBDDs and HLDDs.

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Zou, Xiaoping, and Zhe Sun. "Enhanced Performance of DSSCs Based on the Insertion Energy Level of CdS Quantum Dots." Journal of Chemistry 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/219704.

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Cadmium sulfide (CdS) quantum dots (QDs) are assembled onto the TiO2films by chemical bath deposition method (CBD). And the QDs size is controlled by the times of CBD cycles. They are characterized by UV-visible absorption. To avoid the photo corrosion and electrolyte corrosion, CdS and N719 are sequentially assembled onto the nanocrystalline TiO2films to prepare a CdS/N719 cosensitized photo electrode for the dye-sensitized solar cells. In the structure of TiO2/CdS/N719 electrode, the reorganization of energy levels between CdS and N719 forms a stepwise structure of band-edge levels which is advantageous to the electron injection and hole recovery of CdS and N719 QDs. The open circuit voltage (Voc), short circuit current density (Jsc), and efficiency are increased.

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Al Talaq, Muntathir, and Mohammad Al-Muhaini. "Optimal Coordination of Time Delay Overcurrent Relays for Power Systems with Integrated Renewable Energy Sources." Energies 15, no. 18 (September 15, 2022): 6749. http://dx.doi.org/10.3390/en15186749.

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With the gradual increase in load demand due to population and economic growth, integrating renewable energy sources (RES) into the grid represents a solution for meeting load demand. However, integrating RES might change the power system type from radial to non-radial, where the current can flow forward and backward. Consequently, power system analysis methods must be updated. The impact on power systems includes changes in the load flow affecting the voltage level, equipment sizing, operating modes, and power system protection. Conventional power system protection methods must be updated, as RES integration will change the power flow results and the short circuit levels in the power system. With an RES contribution to short circuit, existing settings might experience missed coordination which will result in unnecessary tripping. This paper considers the impact of integrating renewable energy sources into power system protection on overcurrent time delay settings. A new method to upgrade/adjust time delay settings is developed utilizing genetic algorithm (GA) optimization. The proposed optimization method can be used to evaluate the impact of integrating RES on the exiting overcurrent setting, and can provide new settings without the need to replace existing protection devices when the short circuit is within equipment thermal limits.

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Holanda, Marcelo Alcantara, Ricardo Coelho Reis, Georgia Freire Paiva Winkeler, Simone Castelo Branco Fortaleza, José Wellington de Oliveira Lima, and Eanes Delgado Barros Pereira. "Influence of total face, facial and nasal masks on short-term adverse effects during noninvasive ventilation." Jornal Brasileiro de Pneumologia 35, no. 2 (February 2009): 164–73. http://dx.doi.org/10.1590/s1806-37132009000200010.

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OBJECTIVE: Failure of noninvasive ventilation (NIV) has been associated with short-term adverse effects related to the use of masks. The aim of this study was to compare the incidence, type and intensity of adverse effects, as well as the comfort, of total face masks (TFMs), facial masks (FMs) and nasal masks (NMs) during NIV. METHODS: This was a randomized crossover trial involving 24 healthy volunteers submitted to six sessions of NIV in bilevel positive airway pressure mode using the TFM, FM and NM masks at low and moderate-to-high pressure levels. A written questionnaire was applied in order to evaluate eleven specific adverse effects related to the use of the masks. Comfort was assessed using a visual analog scale. The CO2 exhaled into the ventilator circuit was measured between the mask and the exhalation port. RESULTS: The performance of the TFM was similar to that of the NM and FM in terms of comfort scores. Higher pressure levels reduced comfort and increased adverse effects, regardless of the mask type. When the TFM was used, there were fewer air leaks and less pain at the nose bridge, although there was greater oronasal dryness and claustrophobia. Air leaks were most pronounced when the FM was used. The partial pressure of exhaled CO2 entering the ventilator circuit was zero for the TFM. CONCLUSIONS: The short-term adverse effects caused by NIV interfaces are related to mask type and pressure settings. The TFM is a reliable alternative to the NM and FM. Rebreathing of CO2 from the circuit is less likely to occur when a TFM is used.

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Pop, Flavius, Bernard Herrera, Cristian Cassella, and Matteo Rinaldi. "Modeling and Optimization of Directly Modulated Piezoelectric Micromachined Ultrasonic Transducers." Sensors 21, no. 1 (December 29, 2020): 157. http://dx.doi.org/10.3390/s21010157.

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The present work details a novel approach to increase the transmitting sensitivity of piezoelectric micromachined ultrasonic transducer arrays and performing the direct modulation of digital information on the same device. The direct modulation system can reach 3× higher signal-to-noise ratio level and 3× higher communication range (from 6.2 cm boosted to 18.6 cm) when compared to more traditional continuous wave drive at the same energy consumption levels. When compared for the same transmission performance, the direct modulation consumes 80% less energy compared to the continues wave. The increased performance is achieved with a switching circuit that allows to generate a short high-AC voltage on the ultrasonic array, by using an LC tank and a bipolar junction transistor, starting with a low-DC voltage, making it CMOS-compatible. Since the modulation signal can directly be formed by the transmitted bits (on/off keying encoding) this also serve as the modulation for the data itself, hence direct modulation. The working principle of the circuit is described, optimization is performed relative to several circuital parameters and a high-performance experimental application is demonstrated.

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Journal articles on the topic 'SHORT CIRCUIT LEVELS'

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