Based On The Research Of LoRa Network High-voltage Cable Sheath Circulating Current Detection Device

This article discusses the potential safety hazards of power cables.Real-time monitoring during cable operation can detect hidden dangers in time,prevent the occurrence of major safety accidents on the power grid,and ensure the safe operation of high-voltage power grids.This paper analyzes several existing high-voltage cable insulation monitoring technologies and selects the ground line current method with the LoRa network technology to for on-line monitoring of the cable.Firstly,the various grounding methods of the metal sheathing of the cable and the principle of the circulation current are expounded.The mathematical model of the sheath induced voltage and the ground circulation current of the single-loop high-voltage cable is established.The effects of various factors such as cable length,phase spacing,and cable arrangement on the circulation were analyzed,and simulations were performed in MATLAB.Comparing the calculation results under various conditions,it was found that the cable circulation current under the triangle arrangement is the smallest,and the length of the cross-connected segment should not be too long,which provides a theoretical basis for the detection of circulation current.Secondly,the design scheme of on-line circulating current detection terminal device for high-voltage cable under the condition of internet of things is discussed.The hardware configuration of the circulation detection terminal device is introduced in detail in this article.It mainly includes the signal acquisition and processing module,the terminal device power supply module and the wireless network module.Among them,the power supply scheme of the terminal device adopts an online power acquisition method to solve the power supply problem of the terminal device.With the rapid development of today's Internet of Things technology,the use of Internet of Things to achieve the online monitoring of cable sheath circulation current.The characteristics of the spread spectrum technology adopted by LoRa network are analyzed.After networking,it can take advantage of its long-distance transmission in online circulation current detection.The use of LoRa network combined with the rapid development of the Internet of Things technology,to achieve on-line monitoring of cable sheath circulation.A prototype of an online real-time monitoring system device that can realize the operation of the cable is designed.