Study On SVG-Based Graphic Platform For Power Systems

This page aims at developing a graphic system that can meet requirements of SCADA in power systems and create graphic files in SVG format under the guidance thinking of the universal graphic platform. So it makes research on how to define a graphic file format that can be used in power systems by expanding SVG and how to develop a universal graphic platform. Under the guidance of a criterion of software engineering and using an object-oriented programming method, this paper firstly analyzes the demands in users'view and builds use case diagrams of the system, and then puts forward an open-layered architecture. According to this architecture, the whole system is divided into five parts: the package of the basic graphics elements, the package of the dynamic graphics elements, the package of the graphics management objects, the package of the operating tool and the application layer. The static and dynamic modeling for the system is constructed using UML and the function and interface of each modeling also is defined. Secondly, the whole system is developed with an object-oriented language and the graphic platform WEB publishing system, including its realization in detail and some correlative technology, are also discussed. In order to enhance the reuse of the software, the design pattern, including its concept, common type and using intention is introduced in this paper. On the basis of above, according to the needs of realizing the system, some design patterns are discussed in detail and examples from graphic platform also are given. On the basis of understanding the specification of SVG, this paper expands SVG on macro-lay and micro-lay according to the special requirements of a graphic platform used in power systems. Macro-lay means that a planar file format is extended to file format supporting the multi-layer structure. From micro-lay, the SVG descriptions of all kinds of elements composing a grahpics are given. These elements include the graphic layer, each object in the package of the basic graphic elements and each object in the package of the dynamic graphic elements. Following above rules, the graphic platform can create graphic files that are saved in SVG format, these files naturally inherite all merits and characteristics of SVG. At last, the SCADA system, which is the running environment of the graphic platform, is also studied in this page, including its hardware structure and software environment. Furthermore, the link between the grahpic platform and the real-time database is discussed and some examples of the graphic platform in SCADA are also given.