Research On The Guarantee Technologies Of Communication Networks Reliability In Smart Grid

Power communication network,as an information exchange infrastructure of smart grid and future energy,has a higher demand of reliability and security in the context of Energy Internet constructing.The network structure,service characteristics and information flow distribution of the smart grid determine the formation and resource allocation of power communication network.The reliability of power communication network has a direct impact on the level of smart grid development and operation.The reliability of power communication network needs to be guaranteed by planning and optimizing the physical topology,network performance,service deployment and so on.Therefore,the research on the key technologies of communication network reliability guarantee for smart grid has important theoretical and practical significance.The research of communication network reliability can be divided into two parts:reliability analysis and evaluation,and reliability guarantee promotion.The current researches focus on the reliability analysis and evaluation,and lack the research results of reliability guarantee promotion.This paper analyzes the different characteristics of the communication network reliability for smart grid in the physical layer,network layer and business layer.The key technologies of communication network reliability guarantee are studied from four aspects:economic cost control,network resource utilization,business risk distribution and cascade fault effect.The paper puts forward the reliability guarantee methods and mechanisms for the physical layer,the network layer and the business layer of power communication network at different levels.The main researches and innovations include the following four aspects:(1)In the aspect of physical layer reliability guarantee,with the rapid development of optical fiber network in intelligent power distribution grid,a method of optical fiber network planning optimization with the aim of topology reliability and cost control is proposed,by considering the contradiction between the demand of topology reliability and economic cost control.Based on the location of the future planning site and the existing network topology,this paper constructs the network structure optimization model,and uses the particle swarm optimization algorithm to determine the best network topology planning and optimization.Then,combined with the simulation environment,a city optical transmission network to simulate,the study makes the comparative analysis of the planning optimization scheme from the ring content,economic costs and other factors to verify the proposed method can balance the economy and reliability and realize the optimal cost control under different reliability requirements.(2)In the aspect of network layer reliability guarantee,due to the existence of wireless,PLC and other heterogeneous communication resources in intelligent power distribution grid,a method of optimizing the allocation of heterogeneous resources with reliability and throughput is proposed,by considering the contradiction between the demand for real-time service reliability and the low utilization rate of network resources.In this method,based on two kinds of heterogeneous communication resources of wireless Mesh and PLC,a virtualized scenario is proposed to map the service data processing service to the wireless Mesh and PLC network.By analyzing the bearer mapping relationship between service and network,a virtual mapping model is designed.The optimization function model is established by maximizing the service throughput under the real-time service reliability requirement as the objective function,and the network resource mapping relation as the constraint condition.Then,genetic algorithm and heuristic algorithm are used to determine the optimal allocation scheme of virtual network resources.The simulation results show that the proposed method can improve the network throughput and resource utilization under the premise of guaranteeing the real-time service reliability.(3)In the aspect of service layer reliability guarantee,as a large number of production control and management information services are running in power communication network,a Routing Optimization Mechanism based on Load Balancing is proposed,by considering contradiction between the demand of the important channel reliability guarantee and the unbalanced distribution of the operational risk.In this mechanism,the model of channel routing load optimization is constructed by analyzing the bearing risk relationship between business and network,and the TOPSIS method based on relative entropy is proposed to determine the importance of servives.The risk balance of whole network is taken as the optimization goal,taking into account the whole services risk degree,network risk degree and the load balance degree.A Traffic Routing Algorithm with Load Risk Equilibrium based on the importance of services is propsed,which realizes the optimal selection of new service routing.Then,the simulation results show that the mechanism can effectively reduce the risk of whole network and whole services,and can better balance the important inservices reliability requirements and the overall risk of the whole network operation.(4)In the aspect of network and service cross-layer guarantee,as there is a risk of cascading failure and fault propagation after a failure due to interdependence between power communication network and intelligent microgrid,a cascade fault suppression mechanism of communication network-grid level is proposed based on the interdependent coupling model.In this mechanism,the interdependent coupling network model for power communication network-grid is constructed by combining the service bearing and power supply dependency between power communication network and power grid.A Network-coupling Cascade Mitigation Algorithm is designed based on the interdependent coupling network model to reduce the occurrence of secondary failure,which could inhibit cascade fault and fault propagation and control the range of power related lines,the variation range of the current node and the number of failure of communication nodes.Then,through the simulation experiment,the validity of the algorithm is verified from the angle of failure after power failure and the number of communication failures.It shows that the mechanism can suppress the cascade fault to a certain range between the communication network and power grid,and can guarantee the reliability of the communication network-grid coupling network operation.