Research On Online Monitoring Device For High Voltage Cable Sheath Current

High-voltage transmission cable is an important power infrastructure.However,due to cable theft,fire,and insulation damage,the metal sheath of the cable is short-circuited with the earth,causing huge property damage and threatening personal safety.To this end,this paper designs a high-voltage cable grounding loop monitoring device to monitor the size of the metal sheath ground loop and improve the monitoring capability of the high-voltage cable.The monitoring device is composed of various acquisition modules,data transmission modules and a main controller.Firstly,through the demand analysis,the grounding circulation of the metal sheath of the cable is determined.The running current,temperature,vibration and temperature of the main cable are the monitoring targets.Secondly,to ensure the accuracy,stability and low power consumption of the monitoring device.The design of the hardware circuit is carried out around modules such as microcontroller,current acquisition,temperature acquisition,vibration data acquisition,data communication,etc.Secondly,in order to enhance the scalability and reliability of the monitoring device,the coupling between the various acquisition modules is reduced.With FreeRTOS as the core,the collection task for each monitoring target is designed.At the same time,the operative value of the collected current data is calculated by the ping-pong buffer storage structure and the STM32 floating-point operation set,and the real-time current data is extracted.The effective value of the current data is used to alleviate the pressure of the data transmission bandwidth.Finally,the design of the communication message with the monitoring host is carried out,and the collection information of the monitoring target is encapsulated by the communication message to ensure the accuracy of the data information.Stable transmission.After actual testing,the device can monitor each object,and through the accuracy test of current monitoring,the current measurement error of the device in the monitoring range is controlled at 1.4%,and the error is lower than the current to be measured.0.5% and tends to be stable.