Influence of DC Component of Short-Circuit Current on Arc Characteristics During the Arcing Period

2014 ◽  
Vol 29 (1) ◽  
pp. 81-87 ◽  
Author(s):  
Junmin Zhang ◽  
Jian Lan ◽  
Lei Tian
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Arc Characteristics ◽  
Dc Component

Research on Adaptive Current Protection of Wind Farm

2012 ◽  
Vol 260-261 ◽  
pp. 257-262
Author(s):  
Feng Ting Li ◽  
Chang Sheng Su
Keyword(s):  
Wind Farm ◽  
Short Circuit ◽  
High Sensitivity ◽  
Short Circuit Current ◽  
Phase Selection ◽  
Wind Generators ◽  
Attenuation Characteristic ◽  
Sample Data ◽  
Dc Component ◽  
Current Sample

In allusion to the problems of convention current protection when it was used to collect circuit of wind farm, the relay protection should consider the short-circuit current of wind generators; The principle of adaptive current protection was described, the fault current and attenuation characteristic of asynchronous wind generator was studied, the scheme of adaptive current protection was proposed for wind farm operation. Taking PSCAD/EMTDC as the platform, simulation and record the voltage and current sample-data of different wind farm operation which can guarantee high sensitivity phase selection, the high accuracy wind generators impedance measure method based on FFT filter DC component is presented , and using MATLAB program achieved the scheme of adaptive current protection. Simulation results demonstrate that collect circuit adaptive current protection is adaptive wind farm operation model, and enhance the operation benefit of wind farm.

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.

Study of Generator Source Short-Circuit Currents with Respect to Interrupting the Duty of Generator Circuit Breakers, EMTP Simulation, ANSI/IEEE and IEC Methods

2008 ◽  
Vol 9 (3) ◽  
Author(s):  
J. C Das
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Circuit Breakers ◽  
Time Constants ◽  
Method Of Calculation ◽  
Generator Circuit ◽  
Dc Component ◽  
Current Zero ◽  
Short Circuit Currents ◽  
A Current

Large generators have high effective X/R ratios and combined with other generator time constants and parameters, a current zero may not be obtained at the time of contact parting, i.e., the dc component of the short-circuit current at the contact parting time is higher than the peak ac component. This is well documented in the current literature. The paper presents calculations of the generator source short-circuit currents of a 234 MVA generator using ANSI/IEEE and IEC standards and EMTP simulation. The results are compared and the application of a generator breaker to meet the requirements of calculated duties are discussed. It shows considerable differences in the results, depending upon the method of calculation.

Short-Circuit Current Calculation of a Power System with a Grid-Connected Inverter

2014 ◽  
Vol 1070-1072 ◽  
pp. 823-828
Author(s):  
Wei Cao ◽  
Cong Ngon Do ◽  
Jia Lin Cao ◽  
Jing Sun
Keyword(s):  
Power Supply ◽  
Short Circuit ◽  
Current Source ◽  
Sudden Change ◽  
Short Circuit Current ◽  
Inverter Power Supply ◽  
The Difference ◽  
Dc Component ◽  
Grid Connected Inverter ◽  
Current Calculation

This paper analyzes the difference between conventional power supply and inverter power supply short circuit characteristics, pointing out that the short circuit current does not contain transient DC component. The inverter power supply can be regarded as AC current source with sudden change of current at moment of short-circuit to calculate the current periodic component. The method to calculate the short circuit current of power grid with both conventional rotating generator and inverter power supply is proposed and evaluated.

Analysis of Fault Recorder Data for Short-Circuit Current in a 500kV Busbar Short-Circuit Accident

2011 ◽  
Vol 383-390 ◽  
pp. 1290-1294
Author(s):  
Wei Cao ◽  
Yong Sheng Wang ◽  
Bei Liu ◽  
Wei Wang
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Frequency Component ◽  
Fault Recorder ◽  
Three Phase ◽  
Dc Component ◽  
Grid Operation ◽  
Short Circuit Fault ◽  
Operation And Management ◽  
Fundamental Frequency Component

The three-phase short-circuit fault of the 500 kV busbar of Waigaoqiao No.2 Power Plant was described, and the fault recorder data was analyzed for short-circuit current. The RMS of short-circuit current decaying fundamental frequency component, DC component and the attenuation time constant was obtained by Fourier transform, extrapolating with the exponential function. Finally, Corresponding suggestions for grid operation and management were also proposed.

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