High Capacity High-Speed Switch Application Analysis and Action Process Simulation

2015 ◽  
Vol 1092-1093 ◽  
pp. 276-280
Author(s):  
Tie Ying Zhao ◽  
Jun Ling Liu
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
High Capacity ◽  
Short Circuit Current ◽  
Current Level ◽  
Parallel Structure ◽  
Application Analysis ◽  
Current Limiting ◽  
Simulation Results ◽  
Action Process

This paper analyzed high capacity high speed switch’s works and structures, proposed a parallel structure of high capacity high speed switch (FSR) with current limiting reactor. Through analysis of its action process, this paper used EMTP/ATP to simulate FSR action process, analyzed line current and voltage changes in normal and short circuit station. Simulation results show that the method can effectively limit short circuit current level.

scholarly journals Fault Assessment and Mitigation of the 132kV Transmission Line in Nigeria using Improved Resonant Fault Current Limiting (RFCL) Protection Scheme

2018 ◽  
Vol 3 (10) ◽  
pp. 38-44
Author(s):  
D. C. Idoniboyeobu ◽  
S. L. Braide ◽  
Wigwe Elsie Chioma
Keyword(s):  
Power System ◽  
Transmission Line ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Resonant Circuit ◽  
Fault Current ◽  
Protection Scheme ◽  
Current Limiting ◽  
Simulation Results ◽  
The Impact

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.

New Design of Scan Flip-Flop to Increase Speed and Reduce Power Consumption

2015 ◽  
Vol 24 (10) ◽  
pp. 1550159 ◽  
Author(s):  
Ramin Razmdideh ◽  
Ali Mahani ◽  
Mohsen Saneei
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
High Speed ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Switching Activity ◽  
Flip Flop ◽  
Reduce Power Consumption ◽  
Controlled Switching ◽  
Simulation Results

In this paper, a novel low-power and high-speed pulse triggered scan flip-flop is presented, in which short circuit current is controlled. Switching activity is decreased to reduce the consumed power of the scan flip-flop. Also, the total number of transistors through the path from input to the output is reduced and so the delay of the proposed scan flip-flop is decreased. Simulation results show 12% and 29% reduction in power consumption and delay of the proposed scan flip-flop, respectively. The results are given by comparison of our work with other scan flip-flops at 50% data switching activity.

Fluttering Amplitude Amplification by Utilizing Flapping Moment in Flutter-Driven Triboelectric Nanogenerator

2021 ◽  
Author(s):  
Yi Zhang ◽  
Ka Chung Chan ◽  
Sau Chung Fu ◽  
Christopher Yu Hang Chao
Keyword(s):  
Flow Velocity ◽  
High Speed ◽  
Aerodynamic Force ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Energy Output ◽  
Small Scale ◽  
Triboelectric Nanogenerator ◽  
Peak Value

Abstract Flutter-driven triboelectric nanogenerator (FTENG) is one of the most promising methods to harvest small-scale wind energy. Wind causes self-fluttering motion of a flag in the FTENG to generate electricity by contact electrification. A lot of studies have been conducted to enhance the energy output by increasing the surface charge density of the flag, but only a few researches tried to increase the converting efficiency by enlarging the flapping motion. In this study, we show that by simply replacing the rigid flagpole in the FTENG with a flexible flagpole, the energy conversion efficiency is augmented and the energy output is enhanced. It is found that when the flag flutters, the flagpole also undergoes aerodynamic force. The lift force generated from the fluttering flag applies a periodic rotational moment on the flagpole, and causes the flagpole to vibrate. The vibration of the flagpole, in turn amplifies the flutter of the flag. Both the fluttering dynamics of the flags with rigid and flexible flagpoles have been recorded by a high-speed camera. When the flag was held by a flexible flagpole, the fluttering amplitude and the contact area between the flag and electrode plates were increased. The energy enhancement increased as the flow velocity increased and the enhancement can be 113 times when the wind velocity is 10 m/s. The thickness of the flagpole was investigated. An optimal output of open-circuit voltage reaching 1128 V (peak-to-peak value) or 312.40 V (RMS value), and short-circuit current reaching 127.67 μA (peak-to-peak value) or 31.99 μA (RMS value) at 12.21 m/s flow velocity was achieved. This research presents a simple design to enhance the output performance of an FTENG by amplifying the fluttering amplitude. Based on the performance obtained in this study, the improved FTENG has the potential to apply in a smart city for driving electronic devices as a power source for IoT applications.

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.

Current Limiting Reactor's Reactance Value Selection Based on Short-Circuit Transient Analysis

2013 ◽  
Vol 722 ◽  
pp. 223-227
Author(s):  
Tie Ying Zhao ◽  
Yan Wen Wang
Keyword(s):  
Transient Process ◽  
Transient Analysis ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Engineering Calculation ◽  
Calculation Formula ◽  
Current Limiting ◽  
Current Change ◽  
Short Circuit Fault ◽  
A Current

Current limiting reactor can increase systems short circuit impedance so as to limit short circuit current. Current limiting reactor is directly involved in whole short circuit process when a short circuit fault occurs in a power system, which makes short-circuit current change more complex. Short circuit current level is affected by current limiting reactors parameters; a current limiting reactor with proper impedance value can maintain short-circuit current at an acceptable range. A short circuit transient process of a distributing network with current limiting reactor was analyzed, and the formula of current changing in short circuit transient process was deduced; according to the current changing formula, an engineering calculation formula of current limiting reactors impedance was derived. The case calculation shows that current limiting reactor meeting the need of the engineering calculation formula can reach the system current limiting requirement.

Na+-K+-ATPase and Na+/Ca2+exchange activities in gills of hyperregulatingCarcinus maenas

1999 ◽  
Vol 276 (2) ◽  
pp. R490-R499 ◽  
Author(s):  
Čedomil Lucu ◽  
Gert Flik
Keyword(s):  
Atpase Activity ◽  
Specific Activity ◽  
Short Circuit ◽  
Carcinus Maenas ◽  
High Capacity ◽  
Short Circuit Current ◽  
Total Activity ◽  
Camp Content ◽  
Dependent Protein ◽  
Leaky Epithelium

Na+-K+-ATPase and Na+/Ca2+exchange activities were studied in gills of Carcinus maenas in seawater (SW) and after transfer to dilute seawater (DSW). Carcinushyperregulates its hemolymph osmolarity through active uptake of Na+, Cl−, and Ca2+. In DSW total Na+-K+-ATPase activity in posterior gills quadrupled; Na+/Ca2+exchange specific activity was unaffected, and total activity increased 1.67-fold. Short-circuit current ( Isc) in voltage-clamped posterior gill hemilamellae was −181 μA/cm2in SW and −290 μA/cm2in DSW and up to 90% ouabain sensitive; conductivity was similar in SW or DSW (42 and 46 mS/cm2, respectively) and representative of a leaky epithelium. The new steady state of hemolymph osmolarity 24 h after DSW transfer was preceded, already 3 h after transfer, by increased Na+-K+-ATPase but not Na+/Ca2+exchange activity. Western blot analysis indicated that the amount of Na+-K+-ATPase protein had increased 2.1-fold in crabs acclimated 3 wk to DSW; however, 4 h after DSW transfer no difference in the amount of Na+-K+-ATPase protein was observed. After DSW transfer branchial cAMP content decreased. A negative correlation between branchial Na+-K+-ATPase activity and cAMP content points to rapid regulation of Na+-K+-ATPase through cAMP-dependent protein kinase A activity. Ca2+transport may depend on the high-capacity Na+/Ca2+exchanger coupled to the versatile sodium pump.

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