Method Research And Equipment Development Of Small Current Grounding Line Selection

The probability of single-phase ground fault is very high,which seriously threatens the power supply reliability of the system.It is of great engineering significance to improve the reliability of the system power supply and reduce the economic loss caused by the fault of the grounding fault.Although the small current grounding line selection device has been applied in the field,but the selection line device fault recognition rate is not high in field.It is difficult to meet the current application of small current grounding line selection device application requirements.In this paper,the research work of small current grounding line selection method and device is carried out.Firstly,this paper analyzes the basic characteristics of the fault of the single-phase ground fault of the distribution line at the neutral point and the neutral point by the arc-suppression coil grounding.And the main principles of the fault detection method of the small current grounding fault are studied.Secondly,by investigating the working condition of the power supply company in Shandong province,this paper analyzes the existing problems in running the small current grounding line selection device.At the same time,according to the engineering application requirements,a small current grounding line device to upgrade the basic measures to meet the needs of engineering transformation.Then it provides the four specific measures to determine the grounding line device upgrade management.Then,a new type of small current grounding line selection device based on SFB characteristic of fault transient signal is developed.The aspects of the line selection function,the alarm function and the hardware design are introduced in this paper.According to the field application requirements,the design scheme of the monitoring system of the small current grounding optional device is put forward.And the reliability of the selection device was experimented in the typical ground fault detection.In addition,the performance evaluation system for selecting the selection device based on AHP are proposed.And through the specific case analysis for the small current grounding line selection of the field application selection provides a reference.