Research on Adaptive Current Protection of Wind Farm

2012 ◽  
Vol 260-261 ◽  
pp. 257-262
Author(s):  
Feng Ting Li ◽  
Chang Sheng Su

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.

2013 ◽  
Vol 805-806 ◽  
pp. 412-415
Author(s):  
Zhen Yu Xu ◽  
Jing Qi Su ◽  
Qian He ◽  
Zhen Qiao ◽  
Xu Zhang

The paper builds up a wind farm simulation model by DIgSILENT software, and analyses the short-circuit current (SCC) characteristics of doubly-fed induction generators (DFIGs) and wind farm. Simulation analysis shows that DFIGs have different SCC characteristics compared with synchronous generators. The wind farm only provides little fault current when symmetrical fault occurs in the grid; while under asymmetrically grounding fault, the SCC in wind farm side mainly includes zero-sequence current, which shows that the wind farm has weak power characteristic. After integrating the wind farm into the power grid, sensitivity of current-based protection, transformer differential protection as well as phase selection element will be influenced at some extent. Some countermeasures to reduce the impacts of wind power integration on protection are proposed based on the analysis of the impacts of wind farm on protection.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhuang Hui ◽  
Ming Xiao ◽  
Daozhi Shen ◽  
Jiayun Feng ◽  
Peng Peng ◽  
...  

Abstract With the increase in the use of electronic devices in many different environments, a need has arisen for an easily implemented method for the rapid, sensitive detection of liquids in the vicinity of electronic components. In this work, a high-performance power generator that combines carbon nanoparticles and TiO2 nanowires has been fabricated by sequential electrophoretic deposition (EPD). The open-circuit voltage and short-circuit current of a single generator are found to exceed 0.7 V and 100 μA when 6 μL of water was applied. The generator is also found to have a stable and reproducible response to other liquids. An output voltage of 0.3 V was obtained after 244, 876, 931, and 184 μs, on exposure of the generator to 6 μL of water, ethanol, acetone, and methanol, respectively. The fast response time and high sensitivity to liquids show that the device has great potential for the detection of small quantities of liquid. In addition, the simple easily implemented sequential EPD method ensures the high mechanical strength of the device. This compact, reliable device provides a new method for the sensitive, rapid detection of extraneous liquids before they can impact the performance of electronic circuits, particularly those on printed circuit board.


2013 ◽  
Vol 448-453 ◽  
pp. 1732-1737
Author(s):  
Liu Bin ◽  
Hong Wei Cui ◽  
Li Xu ◽  
Kun Wang ◽  
Zhu Zhan ◽  
...  

This paper analyses the characteristics of large-scale offshore wind farm collection network and the impact of the medium voltage collection system optimization,while from the electrical technology point,it proposes the short circuit current of the collection network computational model and algorithms,based on the principle of equivalent circuit.Taking a wind power coolection system planned for a certain offshore wind farm planning for example, the validity of the model and algorithm is verified.


Author(s):  
V. A. Novobritsky ◽  
D. S. Fedosov

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.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 558
Author(s):  
Eduardo Martínez Carrasco ◽  
María Paz Comech Moreno ◽  
María Teresa Villén Martínez ◽  
Samuel Borroy Vicente

The high penetration of renewable energies will affect the performance of present protection algorithms due to fault current injection from generators based on power electronics. This paper explains the process followed for analyzing this effect on distance protection and the development of a new algorithm that improves its performance in such a scenario. First of all, four commercial protection relays were tested before fault current contribution from photovoltaic system and full converter wind turbines using the hardware in the loop technique. The analysis of results obtained, jointly with a theoretical analysis based on commonly used protection strategy of superimposed quantities, lead to a conclusion about the cause of observed wrong behaviors of present protection algorithms under a high penetration of renewables. According to these conclusions, a new algorithm has been developed to improve the detection of faulted phase selection and directionality on distance protection under a short circuit current fed by renewable energy sources.


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