The Grounding Fault And Preventive Measures Of35kV Power Grid In Zichang District

Distribution network is not only a necessary part of the power system, it is transported to the last part of the power user, it’s directly related to the security and stability of the user’s needs can be met, affecting the stability of the user’s daily consumption, but also for test-powered corporate social and economic benefits. Line to ground fault in the distribution network has always been a class can not be ignored fault conditions, particularly in the areas of forest creatures and easier because of improper planning and the effects of wind, etc., causing repeated ground fault grid. Line distribution network as an important component often due to various environmental factors or design defects grounding fault, especially single-phase ground fault, but accounted for about80%of the distribution network failure. How accurate and timely elect the fault line, and in the short time troubleshooting, and power supply reliability for the realization of the distribution automation are of great significance.This paper selects the sub-region long as the research object County, Long County is located in the Loess Plateau child, mainly rely35kV power supply network, it is critical supply network under the order of the power distribution system connected to the link, for residential electricity scheduling and transport plays a vital role. The actual situation of the sub-wavelength region, respectively, of the wind excitation wires hanging tree and the ground wire to ground fault short circuit fault caused by lightning conducted in-depth research. Both cases were carried out analysis of the specific circumstances of the disaster, and in a targeted manner to establish a corresponding model, proposed solutions, analyzes the impact of strong winds and lightning in the area of single-phase ground.Firstly,35kV grid sub-long area of ground fault event in previous years conducted a statistical analysis of the causes of ground faults and hazards were studied. On this basis, establish a ground fault focus on the content of the study:wind excitation trees shorted to ground and ground fault circuit caused by lightning. Then, with the actual length of the data sub-district, a short circuit caused by ground fault trees wind excitation simulation analysis. Calculated the maximum amplitude of the wire transmission corridor, in order to ensure the safe operation of the wire within a safe distance transmission corridor provides theoretical support. Secondly, the establishment of a transmission line model under lightning, and for the sub-region often take longer to install arresters precautions were quantified analysis. Arresters for installation, the scope of protection to make a detailed study and proposed line of withstanding level and effective measures before and after the installation of lightning protection lightning arrester. Finally, through numerical modeling in the laboratory analysis to verify the validity of the measures taken to improve the installation of surge arresters line of withstanding level.