Research On Insulation Detection Device For Grounding Fault In Substation

Substation DC system provides load for control devices,lighting devices,monitoring devices and so on.It is the basis of reliable operation of substation.With the development of communication technology and computer technology,substation is developing towards integrated automation,and the requirement for stability and reliability is getting higher and higher.In actual production,DC system often occurs bus or branch grounding fault,which causes serious consequences such as malfunction of protection device and stop operation of substation.Therefore,in order to ensure the reliability and stability of substation,it is of great value to study grounding fault diagnosis of DC system.Firstly,this paper introduces the components of DC system in substation,as well as the connection mode and bus selection of DC system,draws the connection diagram of DC system in 110 kV and 220 kV substations,expounds the causes of grounding faults in DC system,classifies grounding faults,and analyses the balanced bridge method,AC signal injection method and DC leakage method in grounding fault detection method.Based on the principle,advantages and disadvantages of flow method,a new fault detection method is proposed.This paper designs a DC grounding detection device from two angles of hardware and software.The hardware device includes sampling module,power module,communication module,etc.With C8051F040 as the core,the overall structure block diagram is drawn,and the functions of each part and the component settings are introduced.Based on the hardware part and the detection principle,the software part is designed by module,including the running program,communication program,display program,etc.The flow chart of the software flow of each part is drawn.The experimental results show that the DC grounding detection device designed in this paper can accurately detect the insulation resistance drop or the grounding fault location in the DC system,which has a certain practical application value.This paper has 33 figures,10 tables and 53 references.