Development Of Intelligent Processing Device Of The Single-phase Grounding Fault Of Distribution Network

The reliability and security power distribution network is closely related to its single-phase ground fault processing.At present,China’s distribution network deals with single phase to ground fault mainly by two different ways as well as storage protection.One is arc suppression coil grounding system,when single-phase transient ground fault happened in distribution network,Petersen coil can compensate for failure point arc,recover insulation fault and improve reliability;However,when single-phase permanent ground fault happened in distribution network,Petersen coil can not make the failure insulation recovery,which causing a security risk,and the small residual flow causes Fault Line is also very difficult.The other is low resistance grounding system,when single-phase ground fault happened,it can accurately and rapidly select and remove the fault line,but as the line will be removed when the transient faults happened,which will reduce the distribution network reliability.The current distribution network for handling single-phase ground fault,can not determine whether it’s transient faults or permanent faults,and it is difficult to balance handling between transient faults and permanent faults,so the safety of power grid operation and reliability of power supply can not be effectively protected.With the development of power distribution network,reliability and security is increasingly demanded and it is increasingly important to solve the above mentioned single-phase distribution network troubleshooting problems.Therefore,this paper elaborated the research status of distribution network for handling single-phase ground fault,analyzed and discussed the characteristics and treatments of the transient single-phase ground fault and permanent single-phase ground fault,proposed a method to identify the nature of the fault.We treated different types of distribution network faults separately depending on the nature of single-phase ground fault.Then the paper describes the overall structure of the distribution network of single-phase ground fault intelligent processing equipment,the main functions and working principle.At last,we designed the secondary system unit which includes a PLC controller,the second peripheral circuits,man-machine interface and software program which includes a control function as well as the main part of the program design.The experimental results show that this new system can run stably and reliably,accurately measure capacity of current distribution network,rapidly diagnose single-phase ground fault nature and this system takes different measures on separately dealing with transient faults and permanent faults,with the design requirements of the basic function,this system can effectively improve the reliability distribution network and security of supply.