Application Of Three-Tier Architecture Based On Service-Oriented Architecture In The Control End Of SCADA

SCADA (Supervisory Control And Data Acquisition) system, that is data acquisition and monitoring control system, is the important part of the power network dispatching automation system.At present, the software design of SCADA mostly adopted traditional C/S architecture, which is client/server architecture. Data processing is carried out by the server communicating with the hardware. Whereas the client is used in human-computer interaction,. As the development demand of dispatching automation system, poor portability and poor scalability of this structure leads to flexibility inadequate, which can't satisfy the urgent demand for the application software scale enlargement and the various software integration, and can't adapt to fast changing environment of the software and hardware. Just because of this, accordance with service concept designing the software becomes a trend, which makes cross-regional monitoring possible. And that SOA (Service-Oriented Architecture) of three-layer architecture emphasis on loose coupling and neutral interface definition, breaks away the fetter from oriented technical solution and can deal with the system development demand.Firstly, the development situation of SCADA system and the being information isolated island problem are analyzed, and SOA three-layer architecture solution is introduced by the thesis. Each business logics in system is packed into server, and combined into a new server according to business process. This can interact with other systems and protect existing investment resource rather than rewriting the logical module. After that, the advantage of SOA system compared with the traditional distributed system is analyzed, the present situation, background and related technical points. Then, based on the SOA distributed system architecture and the work flow based on this architecture are designed according to the loose coupling character of the SOA architecture. Rough particle size loose coupling three services are created according to the practical business of the SCADA system dispatching system, every classes related web services are encapsulated, related WSDL files are created in the .NET platform. And this is successfully deployed on the IIS server. And BEA Aqualogic Service Bus-based platform framework for the integration of SOA applications, the services will be decentralized and integrated information exchange, mutual visits.At last, the coordination relations specification between the servevices and the safety mechanism of the services are discussed, and the safety problems are researched and designed in this thesis.