scholarly journals INTELLIGENT RELAY PROTECTION

2020 ◽  
pp. 30-37
Author(s):  
A. N. Shilin ◽  
A. A. Shilin ◽  
P. V. Dikarev ◽  
O. O. Ahmedova
Keyword(s):  
Smart Grids ◽  
Short Circuit ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Weather Conditions ◽  
External Factors ◽  
Current Voltage ◽  
Environment Temperature ◽  
Protection Devices ◽  
Time Of Year

Currently, with the introduction of electrical smart grids, one of the main problems is increasing the authenticity of turning on the relay protection devices during emergency modes. This is due to the fact that the short circuit current, and therefore setpoint, is affected by large number of external factors, such as the humidity of the earth and the atmosphere, external environment temperature, soil state, terrain, etc. Therefore, the relay protection devices must to take account of the influence of these factors and to introduce automatic correction for the setpoint current, i.e. the device must be intelligent. For solution this problem, the intelligent device was developed, containing a microprocessor and a set of sensors of physical quantities of external factors. A more accurate calculation of the relay protection parameters will allow to increase a sensitivity and to avoid the failures of turning on or false turning on of protection. The results of the research can be applied to create a multidimensional mathematical model allowing automatic to select the relay protection settings based of the initial data on weather conditions, time of year, resistance of the soil, current, voltage, etc.

scholarly journals The.main types of wind turbines-generators in the power supply system

2022 ◽  
Vol 23 (5) ◽  
pp. 71-85
Author(s):  
V. A. Novobritsky ◽  
D. S. Fedosov
Keyword(s):  
Second Harmonic ◽  
Short Circuit ◽  
Separation Of Variables ◽  
Harmonic Component ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Current Transformer ◽  
Correct Operation ◽  
Protection Devices ◽  
Dc Component

THE PURPOSE. This paper considers the problem of relay protection functioning when the current transformer reaches the saturation mode which is provided by transient processes.METHODS. MATLAB Simulink software environment allows reproducing the method of statespace representation by using structural blocks. The model is verified by comparison the time to saturation, obtained by calculation and according to the graphical data of the model. The separation of variables method extracts and graphically displays the investigated components.RESULTS. This paper reveals that applying the requirements of IEC 61869-2:2012 standard, which determines the worst combination of series of unfavorable factors for current transformers in transient mode, can influence a serious impact on the correct operation of relay protection based on current, reactance or differential principle of action. Saturation of the current transformer can lead to both negative results: false operation of relay protection devices and their failure.CONCLUSION. According to the results of the study, it was determined that the presence of a DC component in the primary short-circuit current has the greatest effect on the protection operation. The delays in the restoration of the RMS value of the short-circuit current reached up to 0.3 seconds, which is comparable with the response time of the second protection zones for microprocessor-based relay protection devices. The DC component of the primary current and the presence of residual magnetic induction of the current transformer provides the largest content of the magnetization current, the largest angular error and also the largest content of the second harmonic component in the secondary short-circuit current.

scholarly journals Разработка и исследование туннельных p-i-n-диодов GaAs/AlGaAs для многопереходных преобразователей мощного лазерного излучения

2020 ◽  
Vol 54 (3) ◽  
pp. 285
Author(s):  
В.С. Калиновский ◽  
Е.В. Контрош ◽  
Г.В. Климко ◽  
С.В. Иванов ◽  
В.С. Юферев ◽  
...  
Keyword(s):  
Current Density ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Tunnel Diode ◽  
Tunnel Diodes ◽  
Tunnel Current ◽  
Type Layer ◽  
Current Voltage ◽  
Current Voltage Characteristics

Fabrication of connecting tunnel diodes with high peak tunnel current density exceeding the short-circuit current density of photoactive p−n junctions is an important task in development of multi-junction III−V photovoltaic converters of high-power optical radiation. Based on the results of a numerical simulation of tunnel diode current−voltage characteristics, a method is suggested for raising the peak tunnel current density by connecting a thin undoped i-type layer with thickness of several nanometers between the degenerate layers of a tunnel diode. The method of molecular-beam epitaxy was used to grow p−i−n GaAs/Al0.2Ga0.8As structures of connecting tunnel diodes with peak tunnel current density of up to 200A/cm2 .

scholarly journals Simulation of a perovskite sandwich solar cell with the p-CZTS / p-CH3NH3PbCI3 / p-CZTS absorber layers

2021 ◽  
Vol 877 (1) ◽  
pp. 012001
Author(s):  
Marwah S Mahmood ◽  
N K Hassan
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Current Density ◽  
Short Circuit ◽  
Perovskite Solar Cells ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Current Voltage ◽  
Cell Capacitance

Abstract Perovskite solar cells attract the attention because of their unique properties in photovoltaic cells. Numerical simulation to the structure of Perovskite on p-CZTS/p-CH3NH3PbCI3/p-CZTS absorber layers is performed by using a program solar cell capacitance simulator (SCAPS-1D), with changing absorber layer thickness. The effect of thickness p-CZTS/p-CH3NH3PbCI3/p-CZTS, layers at (3.2μm, 1.8 μm, 1.1 μm) respectively are studied. The obtained results are short circuit current density (Jsc ), open circuit voltage (V oc), fill factor (F. F) and power conversion efficiency (PCE) equal to (28 mA/cm2, 0.83 v, 60.58 % and 14.25 %) respectively at 1.1 μm thickness. Our findings revealed that the dependence of current - voltage characteristics on the thickness of the absorbing layers, an increase in the amount of short circuit current density with an increase in the thickness of the absorption layers and thus led to an increase in the conversion efficiency and improvement of the cell by increasing the thickness of the absorption layers.

The Influence of the Magnetic Field on the Current-Voltage Characteristics of CuPc Nanowires

2019 ◽  
Vol 970 ◽  
pp. 75-81
Author(s):  
Alexey Zavgorodniy ◽  
Aitbek Aimukhanov ◽  
Assylbek Zeinidenov ◽  
Galina Vavilova
Keyword(s):  
Magnetic Field ◽  
Carrier Transport ◽  
Copper Phthalocyanine ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Photosensitive Cell ◽  
Positively Charged

The role of spin states in the process of charge carrier transport in copper phthalocyanine (CuPc) nanowires has been established. According to the data obtained, CuPc nanowires are in the η-phase. The current-voltage characteristics (IVC) of a photosensitive cell based on CuPc nanowires in a magnetic field are investigated. As a result of experiments, it was found that applying an external magnetic field, the spins of two positively charged polarons are oriented in one direction. The channel of formation of the bipolaron is blocked. As a result, a decrease in the short-circuit current of the photosensitive cell is observed by more than 61%.

Influence of Silicon Texturization on the Photovoltaic Properties of CuPc/n-Si Hybrid Solar Cells

2012 ◽  
Vol 531-532 ◽  
pp. 40-44
Author(s):  
Zhi Feng Liu ◽  
Yi Ting Liu
Keyword(s):  
Solar Cell ◽  
Current Density ◽  
Copper Phthalocyanine ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Energy Conversion Efficiency ◽  
Short Circuit Current Density ◽  
Hybrid Solar Cell ◽  
Photovoltaic Properties ◽  
Current Voltage

Hybrid solar cell based on copper-phthalocyanine (CuPc) and textured Si has been fabricated. Influence of silicon texturization on the photovoltaic properties of CuPc/n-Si hybrid solar cell was studied by current-voltage characteristic curves in the dark and under illumination conditions. As a result, it is found that textured Si can improve significantly the performance of hybrid solar cell. It exhibits a three times increase in the short-circuit current density with respect to that of the standard hybrid solar cell, and the short-circuit current density reaches up to 5.4 mA/cm2. In addition, the open-voltage and fill factor are almost constant. The solar-energy conversion efficiency is increased by about three times by the textured Si and achieved about 0.8% under “one Sun” illumination. Furthermore, the possible reasons for this result have been discussed.

Metal/Porous Silicon Schottky Diode Structures as Sensors

2006 ◽  
Vol 915 ◽  
Author(s):  
Tayyar Dzhafarov ◽  
Cigdem Oruc Lus ◽  
Sureyya AYDIN ◽  
Emel Cingi
Keyword(s):  
Porous Silicon ◽  
Schottky Diode ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Current Voltage ◽  
Schottky Type ◽  
Capacitance Characteristics

AbstractIn this work we present data on investigation of the current-voltage and capacitance characteristics of Au/PS Schottky type structures in the presence of different hydrogen-containing solutions (glucose, ethanol, methanol, boric acid, sodium tetraborate pentahydrate, sodium borohydride, benzine, KOH). Generation of the open-circuit voltage and short-circuit current density and capacitance up to 0.55 V, 25 mA/cm2 and 1μF respectively on placing of Au/PS structures in these solutions was discovered. This effect is mainly caused by hydrogen component of solutions. The possible mechanism generation of voltage and capacitance in metal/PS sensors hydrogen-containing solutions is suggested. The advantage of metal/PS Schottky type sensors consists in working without applying external electricity.

Relay Protection Setting Calculation and Analysis of Auxiliary Power System for Hydropower Plants

2014 ◽  
Vol 574 ◽  
pp. 324-328
Author(s):  
Nian Fang ◽  
Xian Shan Li ◽  
Hao Xu ◽  
Yu Long Du
Keyword(s):  
Power System ◽  
Short Circuit ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Hydropower Plant ◽  
System Protection ◽  
Auxiliary Power ◽  
Hydropower Plants ◽  
Actual Operation ◽  
Setting Calculation

The configuration and setting calculation of auxiliary power protection are directly related to the regular and safe operation of the equipments, thereby affecting the security and stability of the power plant. The system features are analyzed in depth according to the operational requirements of auxiliary power system protection in Xiangjiaba hydropower plant ,the system model is built on the basis of the actual project, and a variety of short-circuit current calculations are carried out. At last, the setting of the auxiliary power system relay protection is completed. This thesis also proposes solutions to the emerging problems in the process of protection setting. The results of the setting have been applied to the actual operation and no misoperation or maloperation caused by improper constant setting value has occurred so far in Xiangjiaba hydropower plant.

scholarly journals INFLUENCE OF LIGHT ABSORPTION PROFILE ON THE PERFORMANCE OF ORGANIC PHOTOVOLTAICS

2021 ◽  
Vol 22 (2) ◽  
pp. 135-148
Author(s):  
Abdul Halim Ikram Mohamed ◽  
Mohd Lukman Inche Ibrahim
Keyword(s):  
Active Layer ◽  
Light Absorption ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Absorption Profile ◽  
Current Voltage ◽  
Specific Position ◽  
Very High

We investigate how an enhanced light absorption at a specific position inside the active layer affects the performance of organic photovoltaic cells (OPVs), namely the short-circuit current density ( ), the open-circuit voltage ( ), the fill factor (FF), and the power conversion efficiency (PCE). The performance is calculated using an updated version of a previously published analytical current-voltage model for OPVs, where the updated model allows the light absorption profile to be described by any functions provided that analytical solutions can be produced. We find that the light absorption profile affects the performance through the drift current. When the mobility imbalance is not very high (when the ratio of the mobility of the faster carrier type to the mobility of the slower carrier type is less than about ), the PCE is maximized when the light absorption is concentrated at the center of the active layer. When the mobility imbalance is very high (when the ratio of the mobility of the faster carrier type to the mobility of the slower carrier type is more than approximately ), the PCE is maximized when the light absorption is concentrated near the electrode collecting the slower carrier type. Therefore, it is important to ensure that the light absorption profile is properly tuned so that the performance of OPVs is maximized. Moreover, any efforts that we make to improve the performance should not lead to a light absorption profile that would actually impair the overall performance. ABSTRAK: Kajian ini menilai bagaimana penyerapan cahaya yang tinggi pada bahagian tertentu lapisan aktif mempengaruhi prestasi sel fotovoltaik organik (OPV), iaitu ketumpatan arus litar pintas (Jsc), voltan litar terbuka (Voc), faktor pengisian (FF), dan kecekapan penukaran kuasa (PCE). Prestasi dikira mengguna pakai model terkini yang diperbaharui dari model asal analitikal OPV voltan-arus, di mana model ini membenarkan mana-mana profil penyerapan cahaya digunakan asalkan penyelesaian analitikal terhasil.  Dapatan kajian mendapati profil penyerapan cahaya mempengaruhi prestasi berdasarkan arus hanyut. Apabila ketidakseimbangan pergerakan caj tidak begitu tinggi (di mana nisbah pergerakan pembawa caj laju kepada perlahan adalah kurang daripada 103), PCE menjadi maksimum jika penyerapan cahaya bertumpu pada tengah lapisan aktif. Apabila ketidakseimbangan pergerakan caj sangat tinggi (di mana nisbah pergerakan pembawa caj laju kepada perlahan adalah lebih daripada 104), PCE menjadi maksimum jika penyerapan cahaya bertumpu pada elektrod yang mengutip pembawa caj perlahan. Oleh itu, kedudukan talaan profil penyerapan cahaya yang tepat adalah sangat penting bagi menentukan prestasi OPV dimaksimumkan. Tambahan, apa sahaja usaha penambahbaikan prestasi seharusnya tidak menyebabkan pengurangan keseluruhan prestasi profil penyerapan cahaya.

scholarly journals Improved Short-Circuit Current Calculation of Doubly Fed Wind Turbines With Uninterrupted Excitation

2021 ◽  
Vol 9 ◽  
Author(s):  
Jun Yin
Keyword(s):  
Short Circuit ◽  
Relay Protection ◽  
Control Unit ◽  
Short Circuit Current ◽  
Doubly Fed Induction Generator ◽  
Transient Model ◽  
Real Time Digital Simulator ◽  
Doubly Fed ◽  
Current Calculation ◽  
Actual Control

With the enlarging scale of a doubly fed induction generator (DFIG) connected to a power system, the influence of short-circuit current on the system relay protection could not be ignored. Setting and configuring relay protection would be affected by an imprecise short-circuit current calculation. However, some existing studies only consider the condition that the input is the Crowbar and the rotor excitation is blocked. China's new network standard requires the output reactive support current of a DFIG and will change the characteristics of short-circuit current. To solve this problem, on the basis of analyzing the characters of the transient equivalent potential of a DFIG, the transient model of a DFIG with uninterrupted excitation is provided. Based on the characteristics of a non-abrupt change of flux linkage and the requirement of a new grid standard reactive support current, the short-circuit current calculation method of a DFIG with uninterrupted excitation is put forward. Based on the real-time digital simulator (RTDS), a digital-analog experimental platform containing the actual control unit of the DFIG converter is founded, the proposed short-circuit current root mean square (RMS) value calculating method is validated.

scholarly journals Study The Current Density-Voltage (J-V) Characteristics of α-Fe2O3 Thin Film Prepared by Spray Pyrolysis Technique

2020 ◽  
Vol 25 (1) ◽  
pp. 1-7
Author(s):  
Mohammed Sami Abd ali ◽  
Ahmed Shaker Hussein ◽  
Hayder Mohammed hadi
Keyword(s):  
Current Density ◽  
Fill Factor ◽  
Spray Pyrolysis Technique ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Saturation Current ◽  
Conversion Yield ◽  
Current Voltage

ABSTRACT:   In this work was measured characteristics (current - voltage) for the  (fe2o3 )thin films . The characteristics of the current density-voltage(J-V) were calculated at in both dark and light (100 mw/cm2) conditions. The parameters for this research of the photovoltaic samples, that is, were obtained directly from the curves of the resulting characteristics on the basic variables for the solar cell: the short circuit current density  (Jsc‏  ( ‏ , saturation current (Jo ), open-circuit voltage  (Voc) , fill factor ( FF), and efficiency of solar energy conversion (yield) ƞ ,

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