Research On Congestion Control Of Wireless Sensor Networks For Intelligent Distribution Grid Data Communication

Wireless sensor networks with low cost,no cabling,natural isolation and easy maintenance are the future development trend of smart distribution power grid data communication.It is of great research significance and application value to use wireless sensor network for intelligent distribution grid data communication.As the data of the distribution grid aware of the event there are sudden characteristics,and the concurrent data streams interfere with each other,will cause wireless sensor network data communication routing path congestion,which increased data transmission delay,and the number of packet loss and many other issues.The emergence of problems in wireless sensor networks will affect the safe operation of smart distribution power grid.In this thesis,the problem of congestion control for wireless sensor networks of smart distribution power grid and the quality of service assurance mechanism of wireless sensor networks is studied.The main work of this thesis is as follows:1.The structures of distribution automation system,the data communication requirements of smart distribution power grid,and the structures of wireless sensor network are analyzed.The overall structure and local structure of the wireless sensor network in smart distribution power grid are designed,and the main factors that cause the data congestion of the wireless sensor network are analyzed.2.For the congestion problem in MAC layer,the distribution grid data will classify according to different transmission priority,in order to establish the unfair competition mechanism in wireless transmission channel.A kind of overall dynamic congestion control strategy is applied on the basis of the traditional buffer queue management algorithm based on the nonlinear fluid flow model.A sliding mode learning controller based on iterative idea is designed for congestion control,and compared with the traditional sliding mode controller based on the reference signal tracking performance,packet loss rate and control signals and other indicators and discuss the control effect.3.The performance evaluation system of MAC layer is proposed based on the established congestion control strategy.According to the IEEE 802.15.4 standard MAC protocol,a mathematical model for evaluating the performance of the network is established.In the simulation experiment,the effectiveness of MAC layer congestion control method is evaluated by the performance indexes such as network throughput,effective network throughput,channel collision rate and network communication delay.4.For the network layer congestion,the communication model of wireless sensor network in smart distribution power grid is established,according to the constraints and data transmission real-time requirements of wireless sensor network in smart distribution power grid.The Hamiltonian function of the wireless sensor network communication model of smart distribution power grid is constructed by using the method of Pontryagin 's extreme value.Through the analysis of the existence of extreme conditions,it is judged whether the path is in the optimal path.Finally,the solution of the optimal control model is given.Through the case study and simulation experiment,the performance of the proposed communication model is measured when the network is congested.