Research On Fault Identification And Location Of Distribution Network With Distributed Generation

With the increase of global environmental crisis and the reduction of traditional energy sources,the Distributed Generation(DG)has the advantages of energy saving and environmental protection,economic green,and flexibility,which will lead to a good opportunity for development.The system structure,relay protection,resource allocation,and working methods in the traditional distribution network are all fixed.In the future,more and more DGs will be connected to the distribution network.Traditional distribution network fault identification and location solutions must be improved to eliminate influence.Improvement can be eliminated as much as possible.Users' requirements for power supply quality and reliability have been continuously upgraded,which will attract more researchers to study on fault detection,identification,and positioning of distribution network systems with distributed power supply.This will not only bring better service to users but also form a virtuous circle in the development of distributed power supply.This article describes the development situation of China's distribution network and the research status in fault detection,identification,and positioning.Based on the description of the working principles and development directions of several distributed power sources with the largest share,the paper concludes the principle and analysis,the impact of the system on the fault identification and positioning in the traditional distribution network system with a large number of DGs.The fault characteristics of different capacity and different positions of the DG accessing the distribution network are mainly discussed.Wavelet analysis is an advantageous tool for dealing with transient signals and phase-to-mode transformation can transform the signal into modular domain to improve the quality and effectiveness of fault analysis.A fault identification method based on phase mode conversion and wavelet energy entropy fusion is proposed,various fault types are accurately identified in the DG access system.Using wavelet analysis to deal with the weak fault singal for the single-phase ground fault in the small-current grounding system with the highest failure rate and insignificant fault signal.According to the comparisonbetween the amplitude and pole of the reconstructed line signal in the same frequency band to select the fault line.The accuracy of fault location is directly related to a series of problems such as the stability,reliability,and user satisfaction of the power supply system.The multi-agent technology has the ability to decompose and resolve problems,which provides the fault location for DGs in a large number of access distribution network systems.The multi-agent technology will play a more important role in the future intelligent distribution network.With the cooperation in fault line selection and fault segmentation,a new fault location strategy based on multi-agent technology and wavelet analysis line selection technology is proposed.In order to narrow the fault area as much as possible,the fault location is more objectively searched,the fault location is introduced on the basis of the location of the fault section,and an accurate fault location is also explored.