Research On Networking Method Of Power Line Communication Applied In Distribution Automation

Higher requirements have being proposed for distribution communication network due to the continuous development of intelligent distribution network.Because of the natural communication channel as well as the flexibility and convenience for power line communication(PLC)technology,it has a strong application potential in the field of distribution automation in the medium voltage distribution network.However,the channel environment of the medium voltage distribution network is bad,and the single hop communication distance of PLC nodes is short.So the research on PLC networking algorithm with reliability and flexibility is of great significance.This paper is to study the networking method of PLC in distribution automation.(1)The PLC channel model is established based on theory of partial reflection.Then,two-way channel transmission characteristics of typical medium voltage distribution network topology as well as the influence of channel input impedance on the voltage transmission characteristics are analyzed.On the basis of the above analysis,a frequency selection algorithm based on on-line measurement of channel input reactance is proposed.The simulation results show that the proposed algorithm can filter out a large number of unavailable frequency points under the premise of guaranteeing the communication quality.Thus the frequency optimization speed is improved.(2)A hierarchical classification PLC network architecture combining static and dynamic relay is proposed,and the subnet networking and reconstruction algorithm under this architecture are studied.This network architecture uses static relay to accelerate the networking and reconstruction process,and uses dynamic relay to ensure the flexibility and reliability of subnet structure.An improved hierarchical search algorithm is used for subnet networking.The simulation results show that the above networking algorithm has low computational complexity and fast network speed.By adjusting the weight parameters of the algorithm,it can meet the different requirements of reliability and real-time;A networking reconfiguration algorithm combined with power frequency communication is proposed for subnet reconstruction.This algorithm can link up multiple nodes to the network in a reasonable order quickly,and the reconstructed network is more reasonable.(3)Considering the influence of distribution bus shunt effect in medium voltage distribution,two feasible network subarchitectures under the hierarchical classification PLC network architecture are compared.the former which locate the main node of the PLC subnet at the line exit is more convenient for the maintenance of the main node of the subnet,and the latter which locate the main node of the PLC subnet in the middle of the line can reduce the adverse effect of busbar shunting and improve the economy and reliability of PLC subnet.The network subarchitecture should be selected according to the actual application situation.