A New Fault-Positions Method Based on Interpolation for the Area of Vulnerability to Voltage Sags

2013 ◽  
Vol 325-326 ◽  
pp. 681-686
Author(s):  
Shuang Ya Zhou ◽  
Shun Tao ◽  
Xiang Ning Xiao ◽  
Chao Luo ◽  
Xiao Chen Zhen
Keyword(s):  
Power System ◽  
Short Circuit ◽  
New Method ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Regional Power ◽  
Short Circuit Calculation ◽  
Point Of Common Coupling ◽  
Transformer Winding ◽  
Common Coupling

The area of vulnerability (AOV) of point of common coupling (PCC) can directly reflect the issue of voltage sag caused by faults in power system. In order to calculate the area of vulnerability more accurately and faster, this paper proposes a new fault positions method based on interpolation, which overcomes the blindness of setting fault points. The influence of transformer winding connections on voltage sag is also taken into account. Short-circuit calculation is adopted and transfer matrix representing the transfer law of transformer on voltage sag is deduced firstly. Then, the principle and implementation flow of the new method are presented in detail. Finally, the new method is applied to a regional power system of China, and graphic result of the area of vulnerability is displayed under balanced and unbalanced faults.

A New Method to Detect Voltage Sag Based on Wavelet Energy Entropy

2013 ◽  
Vol 448-453 ◽  
pp. 2254-2258 ◽  
Author(s):  
Chang Gang Wang ◽  
Lin Chuan Wang ◽  
Jia Liu ◽  
Bin Liu
Keyword(s):  
Power System ◽  
New Method ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Peak Voltage ◽  
Wavelet Energy ◽  
Energy Entropy ◽  
Drop Time ◽  
Power System Faults ◽  
Wavelet Energy Entropy

Voltage sags was a common power system disturbance, usually associated with power system faults. Nowadays, there were more and more methods to detect voltage sag, involving with RMS, peak voltage detect, FFT. Owing to their defections, they were too slow when they came to being applied to detect voltages sags. This paper presents a method based on wavelet energy entropy detection voltage sags, this method can detect the drop time quickly and sensitively. In order to verify the feasibility of the proposed method, a numerical example simulation has been done based on matlab / simulink , results show that there is a significant effect.

Research of SC for Improving LVRT Capability of FSIG

2012 ◽  
Vol 512-515 ◽  
pp. 758-762
Author(s):  
Guo Qing Li ◽  
Li Meng Wang
Keyword(s):  
Wind Power ◽  
Reactive Power ◽  
Short Circuit ◽  
Wind Farms ◽  
Mathematic Model ◽  
Point Of Common Coupling ◽  
Fast Development ◽  
Terminal Voltage ◽  
Common Coupling ◽  
Short Circuit Fault

The fast development of wind power generation brings new requirements for wind turbine integration to grid. In order to improve the lower voltage ride through(LVRT) capability of fixed speed induction generator(FSIG) in wind power generating systems, the mathematic model of FSIG, supercapacitor(SC) and converter is built in DIgSILENT in this paper. A control strategy for FSIG and SC based on wind farms is proposed to enhance the terminal voltage of point of common coupling (PCC) after the clearance of an external short circuit fault. The simulation results show that the terminal voltage of PCC can be significantly improved when there is extra active and reactive power compensation available from SC.

Validation of Voltage Sag Simulation Tools: ATP and Short-Circuit Calculation Versus Field Measurements

2008 ◽  
Vol 23 (3) ◽  
pp. 1472-1480 ◽  
Author(s):  
J.M.C. Filho ◽  
R.C. Leborgne ◽  
J.P.G. de Abreu ◽  
E.G.C. Novaes ◽  
M.H.J. Bollen
Keyword(s):  
Short Circuit ◽  
Field Measurements ◽  
Voltage Sag ◽  
Simulation Tools ◽  
Short Circuit Calculation

Impacts of Protection Cooperation on Voltage Sag Frequency and Sensitive Equipment Trips

2012 ◽  
Vol 605-607 ◽  
pp. 819-823
Author(s):  
Li Pin Chen ◽  
Xian Yong Xiao ◽  
Ying Wang ◽  
Jian Jiao
Keyword(s):  
Power System ◽  
State Space ◽  
Test System ◽  
Protection System ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Markov State ◽  
System Components ◽  
Simulation Results ◽  
The Impact

When faults happen to the power system components, the duration of voltage sags is determined by the cooperation of protection system. Many literatures have been done in analyzing the factors which influence the magnitude of voltage sags, but the impact of protection cooperation on sag duration is not considered by existing studies. In order to estimate the duration of voltage sags more precisely, the novelty of the proposed approach is in probabilistic modeling of the cooperation of the protection system using the concept of Markov state space, then voltage sag frequency and sensitive equipment trips considering protection cooperation can be estimated by utilizing the configuration and setting value of the protection system. The proposed method was applied to the IEEE 57-bus test system, and the simulation results show that the proposed method is practical, simple and adaptive.

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