About the Selection of a Single-Phase Short-Circuit Current on Earth in the Network With Low-Ohm Resistive Grounding of the Neutral

2017 ◽  
pp. 34-41
Author(s):  
Andrei V. MAIOROV ◽  
◽  
Kirill A. OSINTSEV ◽  
Andrei V. SHUNTOV ◽  
◽  
...  
Keyword(s):  
Single Phase ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Selection Of

Calculation and Analysis of Three-Phase Transformer Short-Circuit Current

2014 ◽  
Vol 986-987 ◽  
pp. 1914-1917
Author(s):  
Pei Ming Pan ◽  
Huan Lian ◽  
Fei Xiang Hui ◽  
Wei Pu Tan
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Stable Operation ◽  
Application Range ◽  
Three Phase ◽  
Different Types ◽  
Calculation Results ◽  
Current Calculation ◽  
Important Significance ◽  
Selection Of

Analysis the important significance of transformer short-circuit current calculation for the stable operation of power system. Lead to three different types of transformer short-circuit current calculation methods, this literature uses a simplified example to compare the characters among three methods. Meanwhile, calculation by using the theory to get a quantitative range of simplified method. The calculation results and theory support each other, finally, summarizing the application range of the three methods, and offering a reference for reasonable selection of short-circuit current methods.

Research on Stand-Alone PMSG Voltage Stabilizing Method Based on Series Resonance

2012 ◽  
Vol 614-615 ◽  
pp. 1221-1225
Author(s):  
Zheng Hui Li ◽  
Qing Zhi Zhai ◽  
Wen Li
Keyword(s):  
Transient Analysis ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Voltage Fluctuation ◽  
Steady State Analysis ◽  
Series Resonance ◽  
Three Phase ◽  
In Series ◽  
Permanent Magnet Materials ◽  
Selection Of

Stand-alone PMSG has to face voltage fluctuation problems. This paper proposes a kind of voltage stabilizing method based on series resonance in the armature loop and analyses the principle of stabilizing voltage and expounds on the calculation method of series capacitance. Taking a 5kVA three-phase PMSG as an example, we have done the model calculation and simulation, and steady-state analysis results verify the effectiveness of this method. Transient analysis results show that the reasonable selection of capacitance in series has good effects both on limiting short circuit current and avoiding demagnetization of the permanent magnet materials.

scholarly journals Comparative Analysis of High-Voltage Power Line Models for Determining Short-Circuit Currents in Towers Earthing Systems

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4729
Author(s):  
Rafał Tarko ◽  
Jakub Gajdzica ◽  
Wiesław Nowak ◽  
Waldemar Szpyra
Keyword(s):  
High Voltage ◽  
Current Distribution ◽  
Single Phase ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Power Line ◽  
Power Lines ◽  
Distribution Analysis ◽  
Short Circuits ◽  
Short Circuit Currents

The article deals with the problems of single-phase short-circuit current distribution in overhead power lines. Short-circuit disturbances cause many negative phenomena in power networks. Since experimental studies of short-circuits in real networks are practically impossible to perform, these effects can be evaluated only theoretically, based on short-circuit current calculations with the use of appropriate mathematical models. Although short-circuit modeling is considered to be one of the simplest power system calculations, the exact mathematical description of the phenomena occurring at short-circuits is complex. Simplified normative methods are often used for short-circuit current calculations; however, this does not give ground for a thorough analysis of short-circuit current distribution in power lines. The distributions are analyzed using power line models with different degrees of complexity in line with the assumptions made for a given model. The paper presents the problem of current distribution analysis in high-voltage overhead lines for single-phase faults to the tower structures. Simulation studies were conducted on the models developed for the calculation of short-circuit currents in the high-voltage power line earthing. The objective of the analysis was to assess the validity of simplification assumptions followed by practical recommendations on the applicability of the models.

Research of Installing Small Reactors on Neutral Points of 500 KV Autotransformers and the Analysis of Overvoltage

2010 ◽  
Vol 34-35 ◽  
pp. 1609-1613
Author(s):  
Yong Jian Li
Keyword(s):  
Single Phase ◽  
Short Circuit ◽  
Power Grid ◽  
Short Circuit Current ◽  
Neutral Point ◽  
Current Limitation ◽  
Three Phase ◽  
Insulation Coordination

Because of the extensive application of autotransformer in 500 kV power grid, the value of single-phase short-circuit current is generally greater than that of three-phase short-circuit current, or even greater than the maximum rated through current of the breaker. In order to reduce single-phase short-circuit current and avoid implement of bus split, this paper proposes to install small reactors on neutral points of 500 kV autotransformers. By analyzing and calculating the effect on short-circuit current limitation, the most suitable impedance value of small reactor is proposed. In addition，the overvoltage of the neutral point and insulation coordination are particularly discussed.

scholarly journals Influence of the reagents’ ratio on photoelectric and optical properties of perovskite films for photovoltaics

2021 ◽  
Vol 24 (3) ◽  
pp. 295-303
Author(s):  
V.P. Kostylyov ◽  
◽  
A.V. Sachenko ◽  
I.O. Sokolovskyi ◽  
V.M. Vlasiuk ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Single Phase ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Surface Photovoltage ◽  
Material Microstructure ◽  
Photovoltaic Applications ◽  
Limiting Value

The properties of the synthesized films of organic-inorganic perovskites CH3NH3PbI3 obtained at various ratios of starting reagents (PbI2 and CH3NH3I) have been studied. As a solvent, we used chemically pure dried dimethylformamide (DMF). Organic-inorganic perovskites are promising for photovoltaic applications. It has been shown that regardless of the ratio of the starting reagents, single-phase perovskites are formed, at the same time the microstructure of the films changes significantly. It has been reported photoelectric and optical properties of synthesized films, namely: experimental and theoretical spectral dependences of the low-signal surface photovoltage and transmission. The band gap and the Urbach parameter dependence on the ratio of precursors were determined. It has been found that the materials’ band gap depends on the ratio of precursors and equals to 1.59, 1.62 and 1.57 eV, while the characteristic Urbach energy equals to 18, 19 and 22 meV for the PbI2:CH3NH3I films with PbI2 ratio of 1:1, 1:2 and 1:3, respectively. It has been ascertained that the spectral dependences of the low-signal surface photovoltage are much more sensitive to the material microstructure and its electronic structure close to the absorption edge, while the optical transmission spectra are not so sensitive. The limiting value of the short-circuit current density for the films with different PbI2 and CH3NH3I ratios has been determined.

scholarly journals Currents in the overhead transmission line lighting wire in case of single-phase short circuit

2018 ◽  
Vol 69 ◽  
pp. 02010 ◽  
Author(s):  
Kirill Zimin ◽  
Nina Rubtsova ◽  
Vladimir Ryabchenko ◽  
Andrey Tokarskskiy
Keyword(s):  
Thermal Resistance ◽  
Transmission Line ◽  
Simultaneous Determination ◽  
Single Phase ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Overhead Transmission Line

The algorithms for currents induced in a grounded lightning wire (LW) with single-phase short circuit (SC) calculation are considered. It is shown that the method of short-circuit current and current in LW simultaneous determination gives more correct results for the assessment of LW thermal resistance

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