Research On Low Voltage Power Line Communication Network Model Based On Hierarchical Star Structure

As an important branch of smart grid technology,low-voltage power line communication can effectively promote the integration of network technology and computer information technology.At the same time,this technology is also the key technology to realize the integration of four networks of power network,telecommunication network,computer network and cable TV network.At present,it has a wide range of applications in the smart grid information collection,smart home,intelligent building automation and street lighting control system.In the field of related industries,it has also been highly valued.The research of low voltage power line communication is mostly focused on physical layer and data link layer.The research on communication network layer is less,and the research depth is not enough.On the basis of communication reliability,low voltage power line communication network and dynamic routing technology can satisfy the actual structure of low-voltage distribution network,simplify the network mode,make it more scientific and standardized,which are of great significance for the management and maintenance of the network,difficulty and cost of construction.According to the topology of low-voltage power line network,this thesis explored a more suitable,efficient and simple networking scheme of low voltage power line communication on the basis of referring to the current research of power line communication network model and routing algorithm,carries on the design and characteristics research.The work mainly includes the following points:(1)The structure of low-voltage distribution system is analyzed first.Through transformation,low voltage distribution model of a star structure is obtained from the actual low voltage distribution topology.Then,this structure is directly used in low-voltage power line communication network.According to the current key technologies of networking at home and abroad,this thesis presents a new type of low voltage power line network model based on hierarchical star network by using relay technology to realize the requirement of communication distance of each sub network.Based on this,a new network model is explored.(2)According to the model structure,this thesis studied the network principle and the network method,developed a process with networking method,and designs a specific network algorithm.The central point selection algorithm is adopted to select the center point of the star subnet,and the method is also described in detail in this thesis.(3)For the new network model,this thesis formulates the design of routing protocol and the data packet format,expounds data transmission process in detail in the new network communication process.In this thesis,the data transmission protocol of the new network is given.On this basis,aiming at the problem that the power line communication has strong time variant,this thesis developed a dynamic routing reconstruction strategy of the model.When the network communication environment is poor,it can be used for the real-time network environment in order to ensure the reliability of communication.(4)With the help of OPNET network simulation software,this thesis verifies the new network routing protocol.In the same environment,the hierarchical star network model and cluster network model are built respectively,and the polarity data transmission is simulated under the routing protocol.The results show that the proposed protocol can effectively reduce the channel conflict rate on the basis of the realization of normal communication.(5)In the Delphi7.0 compiler environment,the effective communication distance is set to 40 m,and the network is initialized.When the network communication status is worse,the effective distance is set varies from 40 m to 30 m,the dynamic routing characteristics is verified,which obtains good result.On the basis of effectively protecting the communication reliability of fault nodes,the network structure is simplified and the number of relays is reduced,which has a positive effect on the later maintenance and construction of the network.(6)Finally,the time-consuming problem of communication transmission of the new network is studied.Through the comparative analysis,the new type of low-voltage power line communication model in this study is time-consuming.Its transmission time is higher than that of clustering network,but the network model is aimed at the information collection of smart grid,intelligent building automation and other systems with low real-time requirement.It is desirable that the transmission time is spent in exchange for better network systems.