Research On Power Line Carrier Communication Channel Modeling Of Urban Distribution Network

High speed narrow band power line carrier communication(NB-PLC)technology based on multi carrier modulation has overcome many inherent disadvantages of the traditional carrier communication,and has higher anti-interference and adaptive ability.Therefore,the new generation of medium voltage distribution network carrier communication technology research and practical research,is the construction of smart distribution network is an urgent need to break the basic work.In the paper,the urban distribution network power line as the carrier,the channel characteristics of the distribution network are explored in depth.Firstly,the common network topologies of medium voltage distribution network are introduced.And the equivalent mathematical models of carrier communication of the main distribution equipment including medium voltage distribution lines,distribution transformer,switching station,reactive power compensation device are set up.Secondly,the PLC channel modeling method for medium voltage distribution network is studied.Considering the network topology and PLC equivalent model of equipment,two channel modeling methods including theory of partial reflection and branch-adding method are proposed.Simulation and experimental results verify the effectiveness of the two methods.The former only applies to the distribution network power supply model for radial,trunk-like structure,and the latter is not limited by the network topology,with strong applicability.A new method for power line communication(PLC)channel voltage attenuation in medium voltage distribution network based on based on theory of partial reflection is presented.Using the transmission line theory and partial reflection theory,voltage transmission discipline is derived p with transmission line of terminated load and the transmission line cascaded of different characteristic parameters.According to the medium-voltage distribution network topology,the model is cascaded from the end of the distribution network to the carrier source to get the PLC channel model between the end node and the source node.And then the transmission characteristics of the carrier signal at each node are analyzed.A PLC channel modeling method based on branch-adding method is proposed.According to the distribution network topology,gradually increasing each branch of the network which is utilizing branch-adding method,independent equations of VAR and current equations of KCL produced are to create a set of matrix equations which have a unique solution.Based on the matrix equations ratio relationship of unknown variables,signal transfer function is solved and the transmission characteristic of the channel is analyzed.Finally,based on the model and channel modeling method,it focuses on main line length,hybrid lines,branch length and number,the number of distribution transformer and reactive power compensation device for the influence of medium voltage power line carrier signal attenuation.And according to the actual distribution network structure,through the MATLAB simulation and analysis,some common conclusions are drawn,which provides a theoretical guidance for the application of narrow band power line carrier communication used in medium voltage distribution network.