Research And Implementation On XML And Object-Oriented Based Power Quality Data Interchange Mode

Power Quality (PQ) monitoring system and PQ information management system has more than twenty years of development history in China, but it is still in a market to breed and initial level. Different manufacturers produces different format of PQ data in the early days, which go against the sharing and exchanging of the data. IEEE introduced a uniform format PQDIF which makes interchange, sharing, analysis and evaluation of power quality data possible. In one hand, the structure of PQDIF is binary format and its good at data compression. In the other hand, the channel definition is separated with data series, so it is faced with the complexity to orientate in indexes and search or modify files. To analyze PQDIF, it needs the help of self-developed analysis software or third-party software. So it is unlikely to receive and transfer PQDIF in Web-based circumstance.In this paper, the object-oriented modeling technology, based on IEEEP 1159.3 (Draft 11) standard and disturbance classification, classify the PQ data into some types in time-domain, frequency-domain and accident characteristic. Differ from IEEE PQDIF, the object-oriented model in this paper keeps the connection of logic structure between channel definition and data series more closed, making it easy to modify and analyze. Based on the Extensible Markup Language XML, this paper proposed the PQXML model which stored in file. It defines the structure of the model in detail, established UML diagram, gives the class diagrams and mapping rules between XML documents, which greatly improves the versatility of the data model and makes it easier to exchange data between cross-platform and heterogeneous systems. Finally, PQXML standard specifies requirements for data exchange between the master power quality monitoring systems and subsystems from different manufacturers of power quality, consistency and proposed detection method, in order to provide better services for the upper advanced PQ application software in the future.Information model and the method is the core of this paper. Actual applications show that data model and implementation introduced by this paper own well robust and feasibility, can well carry out cross-platform PQ data exchange and sharing. Furthermore, it makes a contribution to promoting the smart grid and the development of the energy interconnection from theory to application.