Research on the On-Line Measuring Method of Transformer Short-Circuit Reactance

2014 ◽  
Vol 981 ◽  
pp. 636-640
Author(s):  
Yun Bing Wei ◽  
Dong Zhang
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Measuring Method ◽  
Electrical Parameters ◽  
Operation Condition ◽  
Current Compensation ◽  
Measuring Methods ◽  
Exciting Current ◽  
Operation Process ◽  
On Line

The short-circuit reactance is an important parameter to characterize the transformer ability to resist the attack of short-circuit current in the design the operation process. In this paper, the on-line measuring method for short-circuit reactance based on electrical parameters' characteristics was presented, and the feasibility to carry out on-line monitoring for the transformer operation condition was also analyzed. Besides, the principle of two on-line measuring methods based on respectively exciting current compensation and elimination technique was researched, and the calculation equations were deduced. The comparison between the on-line results measured from moving mold experiment and those from off-line short-circuit experiment showed that these two methods were accurate and valid.

scholarly journals Acid-Base Transport and Control in Locust Hindgut: Artefacts Caused by Short-Circuit Current

1991 ◽  
Vol 155 (1) ◽  
pp. 455-467
Author(s):  
R. BRENT THOMSON ◽  
N. AUDSLEY ◽  
JOHN E. PHILLIPS
Keyword(s):  
Cyclic Amp ◽  
Acid Secretion ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Salt Bridges ◽  
Electrical Parameters ◽  
Acid Base ◽  
Before And After ◽  
And Control ◽  
Stimulation Of

The commonly used method of passing short-circuit current (Isc) across insect epithelia through Ag-AgCl electrodes, without the use of salt bridges, leads to significant OH− production at the cathode (lumen side) when high currents are applied. The alkalization of the lumen previously reported when cyclic AMP was added to short-circuited locust hindgut is a result of this phenomenon rather than cyclic-AMP-mediated stimulation of acid-base transport in the hindgut. When salt bridges are used to pass short-circuit current across locust hindgut, acid secretion (JH) into the lumen equals alkaline movement (JOH) to the haemocoel side, and JH is similar under both open- and short-circuit conditions. JH is similar (1.5 μequiv cm−2 h−1) in recta and ilea. Addition of cyclic AMP inhibits JH across the rectum by 42–66%, but has no effect on the ileum when salt bridges are used. Electrical parameters (Isc, Vt, Rt) reflecting hindgut Cl− transport (JCL) before and after stimulation with cyclic AMP are the same whether or not salt bridges are used. We found no evidence of any coupling between JCl and JH/JOH.

Online Decision Support Index System Suite for Limiting Short Circuit Current

2013 ◽  
Vol 860-863 ◽  
pp. 1857-1861
Author(s):  
Li Wen Wang ◽  
Bi Qiang Tang ◽  
Ling Ling Pan ◽  
Fei Shi ◽  
Jun Liu
Keyword(s):  
Decision Support ◽  
Index System ◽  
Short Circuit ◽  
Power Grid ◽  
Short Circuit Current ◽  
Indicator System ◽  
Current Level ◽  
System Operation ◽  
On Line ◽  
The Index System

Topology adjustment is a main measure to limit short circuit current, but changes of power grid structure might bring deep impact on power system operation. Measures to limit short circuit current are difficult to apply online due to unable to completely evaluate its safety and feasibility. This paper presents an on-line decision support indicator system, which applied to evaluate online short circuit current level of power grid. Based on practical power grid model and typical cross-section, short circuit current level under the current and future maintenance mode is analyzed, decision support to limit short circuit current is given, and the effectiveness and feasibility of limiting measures are evaluated. Analysis results show that the index system is reasonable.

The influence of emitter resistance on the electrical parameters of mono- and multicrystalline silicon solar cells

2019 ◽  
Vol 36 (3) ◽  
pp. 90-94
Author(s):  
Barbara Swatowska ◽  
Piotr Panek ◽  
Dagmara Michoń ◽  
Aleksandra Drygała
Keyword(s):  
Solar Cells ◽  
Contact Resistance ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Multicrystalline Silicon ◽  
Silicon Solar Cells ◽  
Electrical Parameters ◽  
Content Type ◽  
Diffusion Parameters

Purpose The purpose of this study was the comparison and analysis of the electrical parameters of two kinds of silicon solar cells (mono- and multicrystalline) of different emitter resistance. Design/methodology/approach By controlling of diffusion parameters, silicon mono- (Cz-Si) and multicrystalline (mc-Si) solar cells with different emitter resistance values were produced – 22 and 48 Ω/□. On the basis of current-voltage measurements of cells and contact resistance mapping, the properties of final solar cells based on two different materials were compared. Additionally, the influence of temperature on PV cells efficiency and open circuit voltage (Uoc) were investigated. The PC1D simulation was useful to determine spectral dependence of external quantum efficiency of solar cells with different emitter resistance. The silicon solar cells of 25 cm2 area and 240 µm thickness were investigated. Findings Considering the all stages of cell technology, the best structure is silicon solar cell with sheet resistance (Rsheet) of 45-48 Ω/□. Producing of an emitter with this resistance allowed to obtain cells with a fill factor between 0.725 and 0.758, Uoc between 585 and 612 mV, short circuit current (Isc) between 724 and 820 mA. Originality/value Measurements and analysis confirmed that mono- and multicrystalline silicon solar cells with 48 Ω/□ emitter resistance have better parameters than cells with Rsheet of 22 Ω/□. The contact resistance is the highest for mc-Si with Rsheet of 48 Ω/□ and reaches the value 3.8 Ωcm.

Evidence for separate cellular origins of sodium and acid-base transport in the turtle bladder

1986 ◽  
Vol 250 (4) ◽  
pp. C609-C616 ◽  
Author(s):  
J. H. Durham ◽  
W. Nagel
Keyword(s):  
Epithelial Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Transport Processes ◽  
Electrical Parameters ◽  
Acid Base ◽  
Intracellular Potential ◽  
Turtle Bladder ◽  
Stimulation Of

Transmembrane electrical parameters of the epithelial cells in short-circuited turtle bladders were measured to determine whether those cells participating in Na reabsorption also participate in electrogenic transepithelial acidification and alkalinization. Amiloride-induced increases in intracellular potential (Vsca), apical fractional resistance (FRa), and concomitant decreases in short-circuit current (Isc) denote the participation of the impaled cells in Na reabsorption. In bladders from postabsorptive turtles, amiloride increased Vsca by -45 mV, increased FRa by 37%, and decreased Isc from 36 to -10 microA/cm2. In bladders from NaHCO3-loaded turtles, amiloride increased Vsca by -21 mV, FRa by 21%, and decreased Isc from 22 to 0 microA/cm2. Neither the subsequent inhibition of the negative acidification current in postabsorptive bladders, nor stimulation of positive alkalinization current in bladders from NaHCO3-loaded turtles was associated with any transmembrane electrical change that could be attributed to changes in those transport processes. It is concluded that the electrogenic luminal acidification and alkalinization processes of the turtle bladder are not produced by, or electrically coupled to, those cells that are involved in Na reabsorption.

Comparative Analysis of the Calculation Results of Online Short-Circuit Current Based on PSASP and Fault Wave Recording

2014 ◽  
Vol 1070-1072 ◽  
pp. 897-901
Author(s):  
Guang Ming Lu ◽  
Wei Zhang ◽  
Jian Feng Yan ◽  
Yong Jun Yu ◽  
Zhi Hong Yu ◽  
...  
Keyword(s):  
Power Flow ◽  
Low Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Online Data ◽  
Operation Process ◽  
Depth Analysis ◽  
Forward Calculation ◽  
Current Calculation ◽  
Wave Recording

In daily operation process,the results of online short-circuit current calculation and fault wave recording is different, the differences between the two results affected the dispatcher’s decision. In-depth analysis of the calculation process and finding the possible causes of the differences should be done. The on-line PSASP short-circuit current calculation based on power flow and scheme was studied. The boundary conditions and calculation models of two methods were studied, the influence of the modeling scope and equivalent circuits to the short-circuit current was also studied. Fault wave recording calculated short-circuit current through forward calculation, the middle to both sides calculation and backward calculation, and the differences of the three calculation mode were also analyzed. Through the above analysis and comparison, online data equivalent to 220kV high voltage side of the transformer greatly impacts short-circuit current, but effective value calculation method of fault wave recording has a little impact on the short-circuit current, mainly in the following reasons, the first one is that non-dispatching power plant is equivalent to a load, the second one is that several different types of load is equivalent to a load using one load model, the third one is that all devices connecting to low voltage side of the 220kV transformers are equivalent to 220kV. Conclusions of the analysis can provide the basis for the practical work of online short-circuit current calculation.

Effect of furosemide on the electrical parameters of frog skin

1982 ◽  
Vol 243 (6) ◽  
pp. F581-F587 ◽  
Author(s):  
A. Corcia ◽  
S. R. Caplan
Keyword(s):  
Active Transport ◽  
Frog Skin ◽  
Short Circuit ◽  
Electrical Potential ◽  
Short Circuit Current ◽  
Relative Increase ◽  
Electrical Potential Difference ◽  
Electrical Parameters ◽  
Active Conductance ◽  
Solution Bathing

When added to the mucosal solution bathing isolated frog skin at concentrations ranging from 5 X 10(-4) to 3 X 10(-3) M, the diuretic furosemide increased both the active transport of sodium and the electrical potential difference across the tissue in a dose-dependent way. The same effect was observed in chloride-free solutions. Mucosal furosemide also decreased the passive unidirectional fluxes of chloride. We believe that as far as electrical parameters are concerned mucosal furosemide has a double effect in frog skin: it increases the active conductance to sodium across the mucosal membrane, thus increasing active transport, and decreases the passive permeability to chloride, thus altering the passive conductance of the skin. The relative increase in short-circuit current was, however, invariably greater than the increase of the active conductance, suggesting the influence of yet a third effect. The effect of mucosal furosemide on active sodium transport was blocked by amiloride (5 X 1-(-5) M) and was independent of vasopressin. Qualitatively the effect was similar to the effect produced by triphenylmethylphosphonium ion.

scholarly journals Diagnostic x-ray dosimeters using standard float zone (FZ) and XRA-50 commercial diodes

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Josemary A. C. Gonçalves ◽  
Vinicius S. M. Barros ◽  
Viviane K. Asfora ◽  
Helen J. Khoury ◽  
Carmen C. Bueno
Keyword(s):  
Short Circuit ◽  
Current Mode ◽  
Short Circuit Current ◽  
Sensitivity Coefficient ◽  
Current Sensitivity ◽  
X Ray ◽  
Long Term Stability ◽  
Float Zone ◽  
On Line ◽  
Alternative Choice

The results obtained with a standard float zone (FZ) silicon diode, processed at the Helsinki Institute of Physics, used as on-line diagnostic X-ray dosimeter are described in this work. The device was connected in the short-circuit current mode to the input of an integrating electrometer. The response repeatability and the current sensitivity coefficient of the diode were measured with diagnostic X-ray beams in the range of 40-80 kV. The dose-response of the device, evaluated from 10 mGy up to 500 mGy, was linear with high charge sensitivity. Nevertheless, significant energy dependence was observed in the charge sensitivity of FZ device for energies below 70 kV. The dosimetric characteristics of this FZ diode were compared to those of an XRA-50 commercial Si diode, specially designed to X-ray dosimetry. The results obtained with the  FZ diode evidenced that it can be an alternative choice for diagnostic X-ray dosimetry, although it needs to be calibrated for individual X-ray beam energies. The studies of long-term stability and the radiation hardness of these diodes are under way.

scholarly journals Experimental Investigation of the Effects of Partial Shading on Photovoltaic Cells’ Electrical Parameters

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
W. B. Xiao ◽  
F. Y. Hu ◽  
H. M. Zhang ◽  
H. M. Wu
Keyword(s):  
Open Circuit Voltage ◽  
Short Circuit ◽  
Isosceles Triangle ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Electrical Parameters ◽  
Maximum Power Point ◽  
Partial Shading ◽  
Black Card ◽  
Power Point

The short-circuit current (Isc), the open-circuit voltage (Voc), and the maximum power point (VMPP,IMPP) of monocrystalline and multicrystalline silicon solar cells under three kinds of partial shading patterns have been investigated experimentally. The partial shades are, respectively, the nine shelter locations by 1 cm × 1 cm black card, the six shelter locations by 2 cm × 1 cm black card, and the center shelters with isosceles triangle, circle, square, and two rectangles black cards whose areas are 2 cm2. Firstly, the results show that the partial shading causes disproportional high losses on those parameters of both cells but will have a minimal effect onVoc. Secondly, it is found that those parameters of the monocrystalline cell are less dependent on the shading than that of the multicrystalline cell. Thirdly, it is noted thatIscandIMPPof both cells will be decreasing dramatically as a rectangular black shading card with a long side parallel to cell’s finger, compared with that normal to cell’s finger. Finally, it can be seen that the effects of shading on the electrical parameters of both cells will be suppressed when the border lines of shading match the size of the shaded cell.

scholarly journals Influence of Silicon Nanoparticle on the Electrical Properties of Heterostructured CdTe/CdS thin films based Photovoltaic Device

2021 ◽  
pp. 256-261
Author(s):  
A. A. Faremi ◽  
S. S. Oluyamo ◽  
K. D. Adedayo ◽  
Y. A. Odusote ◽  
O. I. Olusola
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Silicon Nanoparticles ◽  
Short Circuit ◽  
Large Body ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Photovoltaic Device ◽  
Electrical Parameters ◽  
Silicon Nanoparticle

This paper presents the influence of silicon nanoparticles at the interface of heterostructured Cadmium telluride and cadmium sulfide thin films based photovoltaic device with improved electrical parameters leading to tremendous improvement in CdS/CdTe thin f ilm based solar cells performance. The films of CdTe, CdS and Si were electrodeposited using electrodeposition technique to form a heterostructured CdTe/Si/CdS/FTO. The films respective structural properties were also examined using X-ray Diffractometer (XRD) before forming a heterostructured material. The heterostructured CdTe/Si/CdS/FTO and the structure without the inclusion of silicon nanoparticle were examined using electrometer for the extraction of electrical parameters such open circuit voltage (VOC), short circuit current density (JSC), and fill factor (FF). Although a large body of experimental results are available to date on the optoelectronics properties of the materials. However, there is relatively low research studies or works on the electrical properties of the materials. Therefore, we formed heterostructured based photovoltaic device and characterized the structure to determine useful electrical properties. The value obtained for VOC, JSC and FF are 418 mV, 25 mA/cm2 and 0.72 which are indicative of pin holes free semiconductor materials and no leakage path emerging from high-grade materials used in the deposition of heterostructured CdTe/Si/CdS. 

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