Research On Information And Dispatch Technology In Smart Distribution System

In response to the challenges of fossil energy depletion, environmental pollution and inefficient energy systems, the concept of smart grid has been proposed under this condiction, including smart transmission network and smart distribution network. As for smart distribution network, it’s based on advanced automation technology, which includes the application and integration of advanced measurement and sensor technology, control technology, computer and network technology, information and communications technology. Under the physical support of strong infrastructure and two-way communication networks, visual software support which integrates many advanced application functions, renewable energy sources and distributed generation units can be accessed and operated in a microgrid through the use of intelligent switchgear and distribution terminals. Different types of power consumers are encouraged to interact with power producer, in order to have reliable monitoring, protection, control and optimization under normal operation and self-healing control under abnormal operation, and ultimately to provide safe, reliable, high-quality, economical, environmentally friendly power supply and other additional services for the power consumers. The current smart distribution network is facing a number of major scientific research issues. For this reason, the dissertation discussed some problems around information and scheduling technology of smart distribution network. The main work is as follows:1. Firstly, the information in smart distribution network changes dynamicly, which makes interactive mechanism difficult to adapt the users’ envioronment. According to this problem, an algorithm for load pattern recognition based on semantic model is proposed in this dissertation. The algorithm can be used to identify the load behaviors and respond automatically considering the load behaviors, providing appropriate services to meet demands for users. The smart devices and users’ demands are all described using semantic model. When intelligent gateway detects load demands, it will analyze and understand these demands, then provide appropriate services according to the equipment in current environment to help complete user’s behaviors. Semantic association model can make all objects in a smart home be related logically. The results of simulation show that the algorithm based on semantic network model can get higher accuracy than basing on predefined model. Therefore, the proposed model provides a more accurate and effective pattern of interaction between grid and load for active distribution network.2. Secondly, taking intelligent household model extension as an example, the dissertation established extension principles and basic flow of active distribution network information model. By analyzing the function structure of intelligent household and other controllable resources of active distribution network, we abstracted the corresponding classes and properties, compared them with the standard CIM model, located the device properties and relationship structure which are needed to be extended, and set up a series of core classes polymerization system including intelligent household CIM model Smart Home. In addition, by analyzing the specific application, we located the composition of each core packages and their correlated structure of relationship, so as to complete the extension of the overall model.3. Thirdly, the integration of IEC61968 / IEC61850 information model is also studied in this dissertation. On the basis of full analysis of the difference between the two models, complementary integration of model is realized. And then, on the basis of this integration, it is easy for mapping the public part of the IEC61968 and IEC61850 models, so that some existing model mapping method get better mapping transition effects. Addictionally, based on the integration model, IEC61850 configuration file structure and IEC61968 static topology model and message format for active distribution network are designed. In this way, the abstract information model can be converted into metadata, and then applied to the actual configuration and operation of active distribution network system.4. Lastly, based on the structure of IEC standard system integration and interaction design, a coordinated dispatch structure between main and distribution network is established to achieve negative feedback coordinated control of generation, network and load theoretically in active distribution network. In this dissertation, a coordinated optimal dispatch method between main and distribution network is proposed. Through multi-level coordination and stepwise refinement in different time scales, the impact to power grid operation caused by uncertainty of intermittent energy generation is gradually reduced. In addition, through coordinated optimal dispatch between power generation side and load side, the resources from generation and load can be dispatched optimally, which can give full play to flexible adjustment of abundant resources from main and distribution network. Finally, numerical results of a case study demonstrate validity of the proposed method.