Research On Low Time Delay Technology Based On Cognitive Radio In Virtual Power Plant

Virtual power plant is an integrated energy management system based on distributed energy,electric vehicles and load users,which enables distributed energy to participate in the balance of the large power grid and makes it possible for massive power data to become orderly and adjustable.Virtual power plant provides an effective idea for all kinds of intermittent distributed generation to connect to the grid stably,adjust the peak-valley difference of the grid,and reduce carbon emissions.In virtual power plants,there is a relatively large amount of data exchange between distributed energy,electric vehicles and other equipment as well as between load users.These information exchanges need to be transmitted and processed in real time to realize distributed energy aggregation and scheduling optimization management.Considering the limited spectrum resources used in power communication,the communication technology of virtual power plant needs to pay special attention to the allocation and utilization of spectrum resources,while cognitive radio technology can opportunally utilize idle channels to improve the utilization rate of spectrum.Therefore,this paper takes the key technologies of cognitive radio in virtual power plants as the research object,establishes the collaborative spectrum sensing model and spectrum switching mixed priority queue model.The manta ray foraging optimizationgradient based optimizer(MRFO-GBO)algorithm was proposed.Through simulation,parameter analysis is carried out to optimize the accuracy of the cognitive user perception of the main user and spectrum switching delay,and to determine the executable range meeting the service delay of the virtual power plant.The main research content is divided into three parts:1.Study the framework structure of virtual power plant,introduce cognitive radio technology into the wireless communication network of virtual power plant,introduce the theoretical model of spectrum sensing in cognitive radio and spectrum switching mechanism and process,and lay the foundation for the following research;2.The hierarchical architecture of virtual power plant based on cognitive radio is established,and a collaborative spectrum sensing technology based on MRFO-GBO algorithm is proposed to optimize the weight vector of fusion center,so as to improve the detection probability and spectrum utilization.By comparing the simulation examples with other algorithms,it is concluded that MRFO-GBO algorithm can be more effectively used for collaborative spectrum sensing in electric vehicles,and improve the accuracy of the cognitive user perception of the main user.3.Establish a spectrum switching hybrid three-stage PRP/NPRP M/G/m queuing model,and use the proposed MRFO-GBO algorithm to optimize the preemption threshold,so as to reduce the generalized data transmission time.The relationship between important variables in the spectrum switching model is analyzed by simulation and it is verified that the spectrum sensing based on MRFO-GBO algorithm has lower generalized data transmission time under the same parameter Settings.In addition,the simulation study demonstrates that the busy probability of the main user and the busy probability of the cognitive user correspond to different execution ranges according to the different requirements on communication delay of the three kinds of services in the virtual power plant,namely frequency modulation response,load demand response and distributed energy regulation.