Wavelet Analysis In Power System Fault Line Selection

Neutral non-grounded and Petersen—coil grounded systems are also called neutral un-effectual grounded system (NUGS), and they are widely used in power distribution network in China. The single phase-to-ground fault happens most frequently in distribution network. Due to the small fault current and unobvious fault features after single phase-to-ground fault, the problem of fault line selection has been studied for years, however it is still not solved perfectly, which has seriously blocked the development of reliability of power supply and automation level of distribution network.In this paper,the important point is the study about the application of wavelet analysis in single phase grounding fault location of small current grounding power systems,wavelet transform is used as a novel tool of signal analysis to obtain useful fault transient components,a new criterion of fault line selection is constructed based on the time and frequency localization character of wavelet transform.This paper introduces a novel fault circuit selecting method,which utilizes wavelets transform to obtain useful fault transient components.A detailed analysis to fault transient course of these kinds of system is discussed,a fault circuit selecting method based on fault transient components is presented.The basic theory of wavelet transform using in electric system is introduced in this paper.Furtherly,the fault circuit selecting method utilizing wavelets transform is proposed to obtain useful fault transient components.Take advantage of wavelet disposing the transient singular or faint signal,scarcity of the analyzing principle based on steady signal is fetched up and enhance the anti-disturb capability,so that it has higher reliability and accuracy. Lastly,lots of fault circuit selecting SIMULINK experiments are done by MATLAB software.The powerful function of wavelet in the face of singular detection offers an effective pathway to the single phase grounding fault location of small current grounding power systems and makes a significant step for the improvement of automation level in the distribution systems.