The New Line Fault Indicator Design

With the progress and development of society,the quality of power supply of power systems is required to be higher.At present,power failures are almost not allowed in the urban backbone power grid.In the event of a power failure,it is required to locate the fault quickly.As the direction of the development and construction of power system,smart grid requires the monitoring of the operation status of overhead lines,so as to detect and eliminate line faults in time.In the distribution network with increasingly complex structure and operation mode,10 kV overhead line is an important part.It has the characteristics of multiple branches,wide coverage area,line inspection and maintenance time and energy consumption.Therefore,it is usually necessary to install fault indicators on distribution lines to improve the efficiency of finding fault locations of lines,so as to further realize fault control.It can shorten the blackout time and improve the reliability of power supply.However,the current fault indicators have many problems,such as complex structure,high cost of installation and deployment,and inaccurate fault detection.It does not meet the needs of the development of distribution network automation.A new type of fault indicator is designed in this paper.The fault indicator adopts 4G communication mode for data transmission.A wind-solar hybrid power generation system is used to avoid the work of communication cable routing.The GPS coordinate positioning is adopted to help improve the positioning accuracy of the fault point.The lightning information detection function is designed,and the influence of lightning on power grid fault is analyzed comprehensively,which is helpful to reduce fault false detection.The fault detection method is analyzed,and the comprehensive fault detection method is proposed to improve the fault recognition rate and stability.This design adopts the scheme of combining acquisition unit and collection unit into one to reduce the power consumption of the system and reduce the structure of the system.DSP processor and ARM processor are combined.Among them,DSP processor TMS320F28335 realizes the collection,calculation and processing of power grid voltage and current information,and ARM processor STM32F103 realizes the communication between local and upper monitoring system.The dual processor architecture helps the system to improve operating efficiency while reducing development and usage costs.Based on the analysis of the existing problems in the application of the fault indicator,the design requirements and system functions of the new fault indication are proposed,and the overall structural design of the system is completed.According to the overall structure,the selection and circuit design of each functional unit device are completed.Finally,the acquisition accuracy and fault judgment accuracy of fault indicator are tested with relay protection tester and voltage withstand tester.Simulation results and test data show that the proposed transient characteristic remote fault indicator has high accuracy.