Coupling And Attenuation Analysis Of Carrier Signal On Medium Voltage Cable Line

With the introduction of the concept of “Uranium Power Internet of Things” by the State Grid Corporation,it marks that China is moving towards the world-class energy Internet.The realization of “ubiquitous power internet of things” requires advanced information technology,communication technology and intelligent technology to provide sufficient and effective information data.Power line carrier communication utilizes an off-the-shelf power network as a communication channel,which greatly saves investment in building channels,has natural network channel resources and flexible flexibility of application.As a supplement and extension of wireless communication,power line carrier communication is one of the important choices for uranium power internet of things communication technology.In this paper,the medium voltage distribution network with buried cable as the transmission medium is studied.The coupling principle of the embedded inductive coupler,the channel model of the carrier signal and the transmission characteristics are studied in depth.First,according to the main structure of the embedded inductive coupler,the installation and operating environment,combined with the coupling mode of the embedded inductive coupler and the structure of the buried cable of the medium-voltage distribution network,the coupling principle of the embedded inductive coupler is analyzed by using the loosely coupled transformer model.A coupled model of the embedded inductive coupler is proposed.Secondly,the unit length parameter matrix is calculated and analyzed according to the cross-section structure of the buried cable line in the medium-voltage distribution network.Combined with the multi-conductor transmission line theory,the parameter matrix is diagonalized through the loop form analysis and matrix orthogonal transformation.and then based on the actual topology and grounding method of the buried cable line in the medium voltage distribution network,the channel model of the medium voltage distribution network was established using the branch addition method,and the correctness of the channel model is verified by simulation and laboratory simulation.It laid the foundation for studying the transmission characteristics of carrier signals in buried cables of medium voltage distribution networks.Finally,based on the channel model,the influence of the length of the backbone cable,the number of ring network cabinets,the length of the branch cable,the branch cable position,and the number of branch cables(including branch cables at the same ring network cabinet and the different ring network cabinets),the size of the grounding resistance of the ring network cabinet,and the ambient humidity of the buried cable are analyzed on the transmission characteristics of the carrier signal.It provides a reference for the application research of carrier communication technology in buried cable of medium voltage distribution network.