Research On Cognitive Smart Grid Distributed Network Architecture And Its Key Problems

The emergence of smart grid make the communication between information and electric power become a two-way flow. Data transferred from the bottom to the control center, and the control center issued the information from top layer. The whole communication system is highly integrated. In this kind of highly centralized network, the unit in each layer has no interaction between each other so that some can be solved in the lower, but also uploaded to the control center. This thesis mainly focus on smart grid network architecture, analyzed the characteristics of the smart grid centralized network architecture, for its highly centralized communication and power purchase manner insufficient points, designed smart grid distributed network architecture, which has distributed communications, and distributed power interactive, and verify the reasonableness and effectiveness of this distributed network architecture.In this thesis, the existing centralized network architecture is designed to join the hybrid distributed network architecture. Under the distributed network architecture, communication between nodes in each layer can be distributed, in addition to the information communication, it can also interact the electric power, electric power transmission through the direct or indirect way. In this thesis, a distributed network architecture design under three scenarios. 1) In the neighborhood of a distributed network architecture within the network, the DAUs can convey the power of information through cognitive radio technology for the purchase of power resources. 2) In the network architecture which joined the distributed power supply, each DG sale of electricity as an independent party. 3) In a distributed network architecture within a cell, each user generate their own power through distributed generation, after meeting its own demand for electricity, electricity can be traded among themselves. Distributed network architecture makes the whole system in the communications and power purchase has been a greater degree of flexibility.In this thesis, two key issues for spectrum scheduling and power dispatching of distributed network architecture, were analyzed and the corresponding algorithm has been designed. Using a mixed spectrum allocation policy with the combination of temporal and spatial, proposed spectrum scheduling algorithm based on distance threshold, The distance of the cognitive users as a benchmark, adopt different ways of spectrum allocation, to increase its transmission rates, simulation results show this algorithm can improve the transmission rate and success rate of communication. To maximize the distributed power stations sell electricity benefits, proposed power scheduling algorithm based on the auction, distributed power stations will sell their electricity sold at auction way to users, each user of the largest electricity sales gains were selected the sale of electricity, and the algorithm is verified by simulation can achieve higher revenue from electricity sales.Through a large number of simulations, the performance of the distribute network architecture and the whole centralized network architecture has been compared. It had been verified that the distributed network architecture can reduce the user’s electricity expenditure, at the same time meet the needs of the user’s timely response.