| The current traditional power system has served for more than half a century,its load capacity,network architecture,and network intelligence have all failed to keep up with the market demand.A new generation of power networks is urgently needed to be developed and put into use,namely the "power grid 2.0"—Smart Grid.According to the definition of the US Department of Energy's "Grid 2030",the smart grid is a fully automated power transmission network capable of monitoring and controlling each user and power grid node,ensuring the two-way flow of information and electricity between all nodes in the entire transmission and distribution process from the power plant to the end-user.The two-way communication network is indispensable as the brain of the smart grid.Compared with the traditional grid,the smart grid is mainly embodied in the two-way communication network.In the communication network architecture of the smart grid,the core network is mainly constructed by optical fiber networks.The characteristics of the optical fiber can ensure that its communication capacity can support high-speed and efficient transmission of massive data in the smart grid.However,the optical fiber network has problems such as poor scalability,high deployment costs and inflexible cabling etc.,cannot be deployed in the broad coverage required for smart grids.Wireless communication technologies has become an indispensable part of the smart grid communication network with its rapid deployment,low overhead,and strong scalability.As an extension of the fiber backbone network,wireless communication networks can be used to facilitate full coverage of communications,while meeting the access of a large number of users and the flexible expansion of communication networks,and are regarded as the key to implementing monitoring and control functions in the smart grid operating environment.However,there are many new challenges in the application of existing wireless communication technologies in smart grids,which are mainly determined by the unique properties of the power grid:the communication environment of the smart grid is complex;the demand of quality-of-service(QoS)in different types of communication data is significantly different;the coverage is extremely wide;and the distribution is uneven.The existence of these problems all pose challenges to existing wireless communication technologies.This article will make an in-depth analysis of the problems existing while wireless communication technologies applied to the smart grid,and propose corresponding solutions in a targeted manner.Relying on the wireless sensor network architecture in wireless communication technologies,the research focuses on the wireless communication network architecture in smart grid environment,new sensor network architecture design based on software definition,wireless multi-hop network performance research,business hierarchical model design,queuing model research,channel resource allocation model research,and energy-efficient routing transmission mechanism research.The following sections briefly describe the contents of each section:1.The design of wireless communication network architecture in smart gridIn the proper communication network architecture of the smart grid,the construction of the core network must rely on optical fiber communication,only the bandwidth of optical fiber communication can support the interaction of massive data in the smart grid.However,when communication needs to penetrate into specific scenarios such as power stations,substations,transmission lines,and user domains,the flexibility and scalability of wired communication technologies such as optical fiber communication are far from meeting the needs,and their deployment costs and time-consuming do not allow the wired communication go deep into every electrical device.The deployment of multiple wireless communication technologies as nerve endings in different application scenarios will be more suitable for the smart grid environment,but coordination of multiple wireless communication technologies and adaptation to different application scenarios are problems that need to be solved.The main tasks of this section are as follows:First,the overall architecture of the smart grid communication network is studied,and the available of wireless communication technologies in different application scenarios of the smart grid are analyzed.Relying on the wireless sensor network structure,designing multiple feasible network architectures for the entire network and designing different matching wireless network architecture for different application scenarios to ensure that the most suitable wireless communication service can be obtained in different application scenarios and realize each wireless communication sub-network seamless access to the fiber backbone network.2.The design of innovative software-defined sensor networkAs the most suitable wireless communication network structure for the monitoring and control system in the smart grid,the flexible application of the wireless sensor network is indispensable.Existing distributed control and routing algorithms in wireless sensor networks have the following problems:There are computation and information interactions such as route discovery,topology maintenance and node dormancy negotiation,which accelerates the energy consumption of sensor nodes and shortens the lifetime of the nodes and the entire network;sensing data in the network is uploaded to the data center by means of multi-hop transmission,when some nodes in the network are overloaded or the link is broken,the nodes cannot respond quickly and the forwarding rules cannot be adjusted in time,which will cause the entire network to become unstable or even invalid.The main tasks of this section are as follows:Using the idea of centralized control,design a new type of wireless sensor network based on software-defined networks,and integrate software-defined ideas into wireless sensor networks to solve the problems that existing when wireless sensor networks apply to smart grids.Through numerical control separation,the functions of the sensor nodes can be simplified,thereby reducing hardware requirements and energy consumption.The controllers undertake complex calculation and routing planning tasks,and concentrate on the functions of topology discovery,flow table generation and forwarding,and network maintenance.This model will reduce energy consumption,improve stability,and improve the overall performance of wireless sensor networks.Based on the software-defined sensor network,we studied the impact of the number of hops on network connectivity,path reliability,and node mobility in wireless multi-hop networks.In the process of researching these three network performances,corresponding modeling analysis was made to provide technical support for the practical application of wireless sensor networks in the smart grid environment.3.The design of smart grid exclusive business hierarchical modelThe power supply and reliability guarantees in smart grids are not completely average.Power users are classified according to their importance,and different levels have different requirements for power supply reliability.Power grid dispatch must organize power supply strictly according to pre-determined groups when scheduling power resources,especially when power supply is insufficient,it is necessary to prioritize power supply of high-level users.For these grading users,their communication services should also be classified according to their performance requirements.The communication needs of different services also have different focuses.It is necessary to design a flexible business hierarchical model to maximize resource utilization and guarantee the communication needs of users at all levels.The main tasks of this section are as follows:based on the power supply classification,a flexible and adjustable smart grid-specific business hierarchical model is designed based on industry indices,engineering judgments and communication requirements.The model can realize multi-level division of communication priorities and ensure that the priorities of different communication services in different application scenarios can be flexibly adjusted according to requirements to match the performance requirements of communication applications.4.The design of queuing model in smart gridThe wireless communication technologies in the smart grid will face the impact of massive data generated by many services.Different types of data have different requirements for communication performance and service quality.In order to provide different levels of service for different priority services in smart grid applications to match their parameter requirements,a data queuing model needs to be designed to determine which types of data packets can get preferential access to communication services and determine how much communication resources each service uses can get,and what level of service can get.The main tasks of this section are as follows:study the existing wireless communication queuing model,to discuss what defects exist in the existing model when applied to smart grid communication,and to propose corresponding solutions to existing problems.A dedicated queuing model is designed for the smart grid to ensure that the smart grid different priority data can obtain the best service performance.5.The design of smart grid channel resource allocation modelIn order to solve the problem of massive data impact and different quality of service requirements,the channel resource allocation model optimizes network performance from the perspective of wireless communication channel resources.The communication network needs to integrate and rationalize the wireless communication resources,allocate resources according to the requirements,and adapt them to the communication services.The allocation of wireless communication channel resources determines how many channel resources can be obtained by different priority services.The service rate and communication quality can be determined by the channel resource allocation.The main tasks of this section are as follows:design a dedicated channel resource allocation model for the needs of smart grids,and under the premise of ensuring high-priority data service quality,flexibly adjust idle channel resources to maximize resource utilization and improve the fairness of medium-and low-priority data.6.The design of energy-efficient route transmission mechanism of smart gridAs an energy-saving green power network,the smart grid also needs energy-saving and high-efficiency wireless communication technologies.How to reduce the loss of the entire network energy as much as possible while ensuring the communication quality and improve the network lifetime,so that the balance between communication performance and energy is a problem that needs to be paid attention.Although the wireless communication technologies in the smart grid serves the power system,the power transmitted on the power line cannot be directly supplied to various devices in the wireless communication technologies,and its difficult and costly to replace the energy of many nodes,energy saving research is indispensable.The main tasks of this section are as follows:based on the software-defined sensor network architecture design an energy-efficient routing mechanism that adapts to the smart grid environment.Through flexible routing planning,ensure that the energy losses of all nodes of the entire network are balanced to avoid excessive loss of energy in some nodes,reduce the probability of network disconnection.Balance energy consumption of the network while improving the energy efficiency of the network and the service life of the entire network. |
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