| Smart grid is based on power lines and terminal power equipment,and is connected to the information interaction system which composed of a large number of sensing equipment,signal sending and receiving equipment.At present,terminal power equipments communicate with each other through the information interaction system which composed of optical fibers.With the increasing density of terminal power equipment access,the problem of architecture design and cost of optical fibers are difficult to be solved.5G wireless communication technology is expected to solve above problems,which however has high latency and poor delay symmetry.In view of the fact that Mobile Edge Computing(MEC)can reduce the computing delay of communication tasks,this thesis studies the smart grid transmission and computing delay optimization method based on MEC.The main contributions of this thesis are as follows:Firstly,an information interaction system which composed of multiple power equipments and single MEC server is studied.This system includes a ground base station equipped with a MEC server,local power equipment and several adjacent power equipment.The MEC server and local power equipment work together as data processing center.Aiming at the problem of data transmission delay and computation delay of information interaction system,a joint optimization method of task unloading and transmission strategy oriented to MEC was proposed,taking the task processing time of MEC server and power equipment as the influence factor and aiming at minimizing the system delay,the task unloading and transmission strategy were optimized.Simulation results show that the proposed scheme significantly reduces the system delay compared with the uniform task allocation scheme.Then,an information exchange system which composed of a single group of power equipment and a single MEC server is studied.This system includes a cellular base station,a MEC server on the base station side,and a group of power equipment connected by power lines.The power equipment uses wireless communication to carry out information exchange.Aiming at the problem that small scale fading makes it difficult to ensure time delay symmetry in wireless communication,a joint task proportion and power allocation scheme based on time delay symmetry optimization is proposed,taking transmission power and system delay as constraints and minimizing the data transmission and computation delay difference as objectives,the nonlinear programming method is used to solve the problem.The simulation results show that the proposed scheme significantly reduces the delay difference and improves the delay symmetry of the system compared with the power optimization and equal task allocation scheme.Finally,an information exchange system which composed of a single group of power equipment and multiple MEC servers is studied.The system includes multiple ground base stations equipped with MEC servers and a group of power equipment connected by power lines.The power equipment adopts wireless communication mode to carry out information exchange.Aiming at the delay problem of power equipment with limited energy consumption,a power optimization and server selection method based on MEC was proposed,taking energy consumption and power as constraints and minimizing data transmission and computation delay as objectives,the nonlinear programming method was used to solve the constructed problem.Simulation results show that compared with the MEC server random selection scheme,the proposed scheme significantly reduces the system delay. |
