| Sensor node deployment,information collection,node scheduling and routing optimization and other key technologies of the sensing layer are the basis for improving the data reliability and network transmission performance of the power Internet of things.High coverage,low energy consumption,high speed and high precision of the sensor network are the goals pursued by the sensing layer of the power Internet of things.The construction and application of power Internet of things is of great significance to ensure the safe operation of power grid equipment and improve the efficiency of operation and inspection.The difference of operation characteristics of various electrical equipment leads to different requirements for monitoring parameters and indicators.As a result,there are differences in the number of sensor nodes deployed,scheduling strategy and information transmission mechanism.Ordinary heterogeneous networks with multiple types of sensors emphasize the balance between coverage and network life cycle.Event triggered homogeneous networks that monitor rare and unexpected signals have higher requirements for information transmission rate and reliability.Considering the coverage,data reliability and life cycle of the two types of networks,this paper studies the deployment strategy,scheduling method and information transmission routing protocol of sensor nodes in the sensing layer of electrical equipment online monitoring network.The main research contents are as follows.(1)According to the different requirements of electrical equipment monitoring parameters,the deployment strategies of sensor nodes with uniform one-time full coverage of ordinary heterogeneous networks and k-time proportional coverage of key areas are proposed respectively.Firstly,according to the requirements of one-time full coverage of general regional sensor nodes,a PSO algorithm based on Delaunay function is constructed.The uncovered holes of random seeding nodes are calculated by Delaunay function,and the PSO algorithm is used to adjust the nodes to cover the holes until the coverage is equal to 1.Secondly,in order to obtain the accurate signal of the key area of electrical equipment monitoring,when the k-coverage deployment of sensor nodes is needed,a heuristic algorithm based on feedback factor is designed to virtual multiple signal points near the monitoring event hotspot,calculate the European distance between the randomly deployed sensor nodes and the virtual signal points,and use the step-by-step approach method to move the position of sensor nodes to meet the coverage requirements.The simulation results show that the proposed algorithm has strong convergence;Compared with the commonly used greedy algorithm,the k-fold algorithm can reduce the number of sensor nodes.(2)On the basis of ensuring the coverage,in order to alleviate the communication pressure of subordinate sensor nodes under all working conditions and reduce the network power consumption,the clustering and node sleep scheduling method of associated node energy consumption,cooperative game packet allocation and opportunistic routing optimization algorithm are studied.Based on LEACH clustering information collection principle,many sensor nodes in ordinary heterogeneous networks are clustered and managed.The cluster head is selected with cluster head probability and node residual energy as parameters,and some nodes far from the cluster head are dormant,so as to reduce traffic and network energy consumption.During information transmission,the cluster heads carrying data packets are first formed into game clusters,then the data packets are redistributed according to the cooperative game results of distance utility product to balance the amount of data forwarded by cluster heads,and then the forwarding packet route is selected according to the energy distance cost to balance information reliability and network power consumption.The experimental simulation analysis shows that the node sleep method can prolong the network life cycle by about 25%,and the cooperative game packet allocation and opportunistic routing optimization can further prolong the network life cycle by 20%.(3)In the event triggered isomorphic network for on-line partial discharge monitoring of electrical equipment,the sensing angle of ultrasonic sensor monitoring partial discharge signal is limited.During the deployment of sensor nodes,the direction of sensor nodes is changed according to the virtual force,and the angle of sensor nodes is adjusted according to the coverage redundancy.An optimization strategy of sensor node deployment based on variable angle and virtual force is proposed.The goal is to improve sensor node coverage and network stability.(4)Considering the signal capture rate,network life cycle and information transmission reliability of event triggered isomorphic network,a multi node information acquisition and guard protocol and information transmission dynamic alliance routing algorithm are proposed.Due to the rarity and burst of partial discharge signals,in order to ensure the accurate capture of partial discharge signals and the low-power operation of the network,a sentinel protocol for sentinel node selection and neighbor node wake-up during multi node information acquisition is proposed,and the algorithm flow of the sentinel protocol is given.In order to upload the captured signal to the base station reliably and quickly,the alliance master node is selected based on the energy threshold and radius,and the next hop information forwarding node is determined according to the maximum membership degree of energy distance,so as to form a dynamic link of information transmission.Simulation results show that the sentry protocol takes into account the signal acquisition rate and network power consumption,and the dynamic alliance routing algorithm balances the reliable transmission of information and network power consumption. |
