| Autor: |
Sayenko, Yu. L., Nesterovych, V. V., Popov, A. S. |
| Předmět: |
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| Zdroj: |
Scientific Bulletin of National Mining University; 2014, Issue 5, p69-75, 7p |
| Abstrakt: |
Purpose. Analysis of the operating principles of known protection devices for ferroresonance phenomena in networks with isolated neutral point. Identifying the features of the transient ferroresonance processes. Development of the algorithm and protective device for voltage transformers against ferroresonance processes, validation and testing performance of the proposed solutions. Methodology. Mathematical model of electrical networks with isolated neutral was developed. The processes of ferroresonance phenomena and single-phase earth arc fault were simulated. Physical modeling techniques were used in evaluating the efficiency of protection devices against ferroresonance phenomena. Experimental methods were used in determining the parameters of voltage transformers necessary for mathematical modeling. Findings. The analysis of the operating principle of widely known protection devices against ferroresonance phenomena was performed. It was found that in the singlephase arc ground fault mode false functioning of protection devices against ferroresonance is possible. Due to the mathematical modeling of transients frequency range of the ferroresonance oscillations was received. A method of identification the ferroresonance mode based on the spectral analysis of voltage 3u0 and method of identification single-phase arc ground fault mode based on calculating the derivative voltage 3u0 were proposed. The correctness and functionality of the proposed algorithms were verified by means of the test signals to input of protection devices. Originality. Scientifically proved The method of the ferroresonance mode identification in network with isolated neutral point was scientifically proved, it is different from the known one by filtering of 3u0 voltage (Fourier analysis is used instead of the band-stop filter) that allows more accurately detect the type of the transient. The method of identification of single-phase arc ground fault mode was improved. This method is based on computing the derivative of the 3u0 voltage and cooperation with set point that allows to prevent false function of protection devices at the single-phase arc ground fault mode. Practical value. Protection algorithm of measuring voltage transformers against ferroresonance processes was created. The protection device based on this algorithm was developed. The proposed methods of identification of transients may be used for protection against single-phase ground fault in networks with isolated neutral. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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