Analysis of low voltage arcing characteristic on direct short circuit through arcing thermal synchronization sensing and short circuit current

2017 ◽  
Author(s):  
Dimas Anton Asfani ◽  
I Made Yulistya Negara ◽  
Daniar Fahmi ◽  
Rifki Wiryatama ◽  
Muhammad Wildan Arinal Haq ◽  
...  
Keyword(s):  
Low Voltage ◽  
Short Circuit ◽  
Short Circuit Current

scholarly journals Thermal Analysis of Heat Distribution in Busbars during Rated Current Flow in Low-Voltage Industrial Switchgear

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2427
Author(s):  
Michał Szulborski ◽  
Sebastian Łapczyński ◽  
Łukasz Kolimas
Keyword(s):  
Structural Changes ◽  
Heat Dissipation ◽  
Current Flow ◽  
Low Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Coupled Analysis ◽  
Precise Representation ◽  
Transient Thermal ◽  
Halogen Free

The manuscript presents advanced coupled analysis: Maxwell 3D, Transient Thermal and Fluent CFD, at the time of a rated current occurring on the main busbars in the low-voltage switchgear. The simulations were procured in order to aid the design process of such enclosures. The analysis presented the rated current flow in the switchgear busbars, which allowed determining their temperature values. The main assumption of the simulation was measurements of temperature rise during rated current conditions. Simulating such conditions is a valuable asset in order to design better solutions for energy distribution gear. The simulation model was a precise representation of the actual prototype of the switchgear. Simulations results were validated by experimental research. The heat dissipation in busbars and switchgear housing through air convection was presented. The temperature distribution for the insulators in the rail bridge made of fireproof material was considered: halogen-free polyester. The results obtained during the simulation allowed for a detailed analysis of switchgear design and proper conclusions in practical and theoretical aspects. That helped in introducing structural changes in the prepared prototype of the switchgear at the design and construction stages. Deep analysis of the simulation results allowed for the development concerning the final prototype of the switchgear, which could be subjected to the full type tests. Additionally, short-circuit current simulations were procured and presented.

scholarly journals Bidirectional Short-Circuit Current Blocker for DC Microgrid Based on Solid-State Circuit Breaker

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 306 ◽  
Author(s):  
Lujun Wang ◽  
Boyu Feng ◽  
Yu Wang ◽  
Tiezhou Wu ◽  
Huipin Lin
Keyword(s):  
Solid State ◽  
Low Voltage ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Rotational Inertia ◽  
Dc Microgrid ◽  
Protection Strategy ◽  
Solid State Circuit ◽  
Solid State Circuit Breaker

In order to solve the imminent problem in that the traditional protection strategy cannot meet time requirements, together with the fact that the rotational inertia of a DC microgrid is small and short-circuit fault develops rapidly, a bidirectional short-circuit current blocker (BSCCB) based on solid-state circuit breaker for a DC microgrid is proposed. Firstly, the bidirectional current blocking circuit structure is proposed based on the analysis of key components. Then, a top-level differential protection strategy is developed based on the aforementioned proposal. Finally, the performance of the blocking circuit is simulated and verified by experiments. The results show that the proposed method can block short-circuit current within 4 ms, and the response speed of the protection strategy is very fast compared with previous approaches. BSCCB also has reclosing, bidirectional blocking and energy releasing functions. The current blocker proposed in this paper can be reused multiple times and has a promising future in low-voltage DC microgrid application.

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.

scholarly journals Regularities of Control of Mechanized Pulse-Arc Welding Process for Ensuring its Stability

2019 ◽  
pp. 65-76
Author(s):  
S. Yu. Maksymov ◽  
L. S. Shlapak ◽  
А. А. Havryliuk ◽  
І. М. Semianyk ◽  
V. А. Onyskiv
Keyword(s):  
Arc Welding ◽  
Low Voltage ◽  
Short Circuit ◽  
Welding Current ◽  
Short Circuit Current ◽  
Average Frequency ◽  
Maximum Value ◽  
Current Growth ◽  
Short Circuits ◽  
Electrode Metal

Mechanized arc welding in protective gases with short circuits (s.c.) is performed at moderate values of the welding current (up to 180 ... 220 A) and at the relatively low voltage (18 ... 24 V) on the arc. The main disadvantage of the process is spattering when melting an electrode metal and when transferring it to a weld bath. The elimination of disadvantages is possible through the implementation of a controlled transfer of molten electrode metal to a welding bath - due to the pulsed nature of arc burning.  At pulse-arc welding (PAW), one of the main methods of increasing the efficiency of the process is to limit the maximum value of the short-circuit current Imax s.c. by increasing the inductive resistance L in the arc-welding circuit. Proceeding from the features of mechanized arc welding, the purpose of the research is to specify the influence of the velocity of the growth of the welding current vс during the s.c. on the arc stability. The implementation of experimental work presupposes surfacing on a plate with the programming of the operating mode of the inverter at different values (9, 12, 15, 18, 21, 24, 27, 30) with the frequency f = 25 Hz and a pulse ratio C = 2. While analyzing oscillograms of welding current and processing their records, it was established that a decrease of the velocity of the welding current growth leads to a significant limitation of the maximum value of the short-circuit current. The statistical processing of the momentary values of the welding current shows that the increase in the velocity of current growth vс starting with vс = 1.23 kA / s to vс = 50 kA / s makes the average short-circuit duration 10 times shorter. At the same time, the average frequency of short circuits grows more than twice. The increase of vс leads to the destabilization of the pulse process and this is reflected in the 30-times increase of the average frequency of arc break. The increase of the energy indexes of the PAW to the Iav. = 220 ... 225 A, Uav. = 24.5 ... 25.9 V, Q ≈ 7.9 ... 8.0 kJ / cm led to the changes in the parameters which characterize the process of pulsed welding with short circuits. There is a sharp decrease in the average frequency of short circuits (2 ... 3 times as rarely) and the average duration of s.c. (twice shorter).

scholarly journals Integrated Power Flow and Short Circuit Calculation Method for Distribution Network with Inverter Based Distributed Generation

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Shan Yang ◽  
Xiangqian Tong
Keyword(s):  
Distributed Generation ◽  
Calculation Method ◽  
Power Flow ◽  
Low Voltage ◽  
Short Circuit ◽  
Distribution Network ◽  
Short Circuit Current ◽  
Theoretical Research ◽  
Equivalent Model ◽  
Short Circuit Calculation

Power flow calculation and short circuit calculation are the basis of theoretical research for distribution network with inverter based distributed generation. The similarity of equivalent model for inverter based distributed generation during normal and fault conditions of distribution network and the differences between power flow and short circuit calculation are analyzed in this paper. Then an integrated power flow and short circuit calculation method for distribution network with inverter based distributed generation is proposed. The proposed method let the inverter based distributed generation be equivalent toIθbus, which makes it suitable to calculate the power flow of distribution network with a current limited inverter based distributed generation. And the low voltage ride through capability of inverter based distributed generation can be considered as well in this paper. Finally, some tests of power flow and short circuit current calculation are performed on a 33-bus distribution network. The calculated results from the proposed method in this paper are contrasted with those by the traditional method and the simulation method, whose results have verified the effectiveness of the integrated method suggested in this paper.

scholarly journals METHOD OF ASYNCHRONOUS ENGINES EQUIVALENCY FOR CALCULATING SHORT CIRCUIT CURRENT IN A SYSTEM OF BALANCE-OF-PLANT NEEDS

2020 ◽  
pp. 102-115
Author(s):  
Abdullo Sh. Majidov ◽  
Yury P. Gusev
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Low Voltage ◽  
Short Circuit ◽  
Balance Of Power ◽  
Short Circuit Current ◽  
Initial Moment ◽  
Plant Design ◽  
Balance Of Plant ◽  
Asynchronous Motors

In short-circuiting in power plants of balance-of-power plant needs three-phase asynchronous motors with a short-closed rotor have a significant influence on the nature of the process and the magnitude of the short circuit current. In the system of balance-of-plant needs it is necessary to take into account the components of short circuit current from asynchronous motors when selecting and checking switches, as well as when selecting and checking current-carrying parts (cables, complete current wires, etc.) not only at the initial moment of the short circuit, but at the time of its shutdown as well. The methods for calculating short circuit current taking into account the influence of asynchronous motors continue to be improved; there is a search for new methods that simplify calculations as much as possible while maintaining the credibility of the results. In doing so, some issues require further study and research, such as the possibility of asynchronous motors equivalency. Power plants have to take into account the components of the short circuit current from a large number of asynchronous engines, which is not only time-consuming, but sometimes impossible due to the absence of full information on engines and mechanisms of balance-of-plant needs. To improve the efficiency and accuracy of calculations for power plant design tasks, it is advisable to replace asynchronous engine groups with equivalents. The relevance of improving the method of equivalency of asynchronous engines at power plants increases along with increasing requirements to enhance the reliability of electrical installations of balance-of-power plant needs and to reduce the costs of technical inventory due to calculation errors. The article considers the method for equivalencing the group of low-voltage asynchronous motors on the example of the balance-of-plant needs system at TPP № 1 located in the town of Dushanbe of the Republic of Tajikistan. Modeling the electromechanical processes caused by short circuits of different electrical remoteness was carried out using ETAP software complex (OTI, USA).

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