Study On Energy Efficiency And Lag Property Of Wireless Sensor Network In Microgrid

Microgrid provides an effective support for the management of distributed power in the large power grid which is an important part in the smart grid construction and development. With the development of wireless communication technology, the application of wireless sensor networks(WSN) will significantly improve the flexibility and extension of the power grid. However, due to some realistic constraints such as energy consumption, spectrum resources and node location and other factors, some communication problems will be caused in microgrid wireless sensor network, such as lack of energy, scarce spectrum resources, imprecise fault location and data reception is not synchronized, which will not only effect the normal operation of the microgrid communications system, but also bring a negative impact on the regulation speed of microgrid control system, and undermine the stability of the microgrid operation.This article will study on the energy efficiency of wireless sensor networks in the microgrid, analysis the role of communications network in stable operation of the power system, and build models for the optimization of data compression, spectrum allocation and node localization in wireless sensor networks according to the communication needs, real time, accurate and low-power, then propose the correct optimization strategy. Meanwhile, for the time lag problem prevalent in wireless communication, collect data in the chamber of the distribution network of Transmission Delay through independent research and development of the wireless sensor networks, and demonstrate the exact impact on the stable operation of the power system caused by time-delay factorswith the method of cases analysis and simulation experiments, in order to provide the basis for the design of subsequent amendments to the feedback controller.The main work and innovative point of this thesis are shown as follows:â‘  According to the problem ofdata transmission delay andexcessive energy consumption of nodesin wireless sensor networks of microgrid faced with the large data,reduce the amount of data processing based on the theory of compressed sensing data compression technology to, in order to achieve alleviate node energy consumption and reduce congestion delay. Improve self-adaptive compressed sensing algorithm by calculating the entropy to select an observation vector and regardless of the residual energy issues.Come with that the node energy could also be a factor determining the observed vector of choice, in order to avoiding the work stop due to the excessive energy consumption in individual nodes because ofalgorithm to choose the same transmission path in the network.The improved algorithm could reduce the overall data transmission amount,balance the wireless sensor network load of each node, extend the network lifetime and meet the energy requirements of the purpose of the microgrid.Finally, comparethe data compression ratio, the convergence speed, the reconstructed data accuracyand the network lifetime under the micro grid control model.â‘¡ According to the problem of large network scale andcommunication bandwidth shortage and spectrum resource due to the large number of node device in wireless sensor networks of microgrid, the cognitive radio technology is used to achieve the purpose of optimizing the spectrum transmission efficiency and reducing the delay in this paper; Improvethe problem of the convergence of the algorithm, and introducethetime slot variables and the decision function to constrain the time domain convergence of the utility function, in order to avoid the generation of multiple Nash equilibrium, makes the algorithm optimize the allocation of spectrum resources and avoid the instability of the shock.Then verifythe convergence and efficiency of the improved algorithm and the traditional algorithm through the digital micro grid experiments.â‘¢ According to the requirement of high accuracy of the device location information in the function of on-line monitoring and fault location and low energy consumption of sensor nodes, the node localization technology in wireless sensor networks is studied.Due to the shortcomings of highcomplexity and energy consumption in the traditional APIT positioning algorithm, an optimization strategy is proposed to use signal strength indicator ranging from unknown nodes and anchor nodes as the edges of a triangle to locate the unknown nodes. It could effectively reduce the complexity of the localization algorithm, improve the positioning accuracy of the same conditions and also an important help to meet the needs of the microgrid node localization. Thendemonstrate the accuracy of the APIT algorithm and the improved algorithm through simulation experiments.â‘£ The effect of feedback delay on the stability of power system is studied.The paper analyzes the causes and types of the time delay, uses the micro network test control console and the wireless sensor network which is independently developedto collect the data of time delay, analyze the effect of time delay on the state response of the system by numerical examples on the basis;the IEEE9 node system model is built to simulate the control system and research the influence of time delay on the load, which provides a theoretical support for the stability control strategy of the micro network control system under the time delay condition.