Advanced PQDIF Power Quality Data Exchange Model And Its Implementation

Power quality (PQ) has been an important issue to the electric power utilities for the changes of loads composition in modern power systems and with the development of power market. The main problems in power quality are monitoring, control and evaluation, and power quality monitoring, which has been a significant part in power quality study, is the foundation for other research and work. In recent years, PQ monitoring system and PQ information management system have attracted more and more people's attentions inside and outside. PQ analysis,detection,monitoring,classification,identication,analysis softwares of high level and so on have gotten progress in different extent. On the base of that, it is going in the direction of PQ information net based on WEB.On-line PQ monitoring in our country usually set data centers in small area based on only one kind of monitoring equipment. Their communication ways base on Modem or Ethernet and so on. These ways have some obvious problems: firstly, data can't be exchanged between different monitoring equipments. Data can't be shared. Secondly, PQ indexes are different from each other in different sites. Indexes are increasing all the time. Meanwhile, data centers aren't so smart and are hard to maintain. Thirdly, recently data analysis are still rest on collection and stat. There isn't any ES.Quality of data in open and sharing aspects among monitoring equipments, analysis softwares, information management systems and WEB servers have already become important issue to be deal with. PQ data own lots of types and complex structure. In order to carry out data sharing, it is necessary to constitute a data sharing model. So IEEE introduced a uniform PQ data format-PQDIF. It has better quality of structure and compression. But it is binary so it isn't so easy for softwares in bottom to read and parse. Channel definition are separated with data series, so it is faced with complexity to orientate in indexes and search or modify files. In some literatures, recording data are classified into some types in time-domain, frequency-domain and accident characteristic. Classification is easy. However, it is so different with structure of PQDIF, occupies so many spaces and is hard to extend to applications.An optimizing PQ data model based on XML and its cross-platform implementation are introduced; Using base64bianary storage format, space occupied by data can be decreased effectively; data types are nested as subobjects in PQ XML model so that connection of logic structure between channel definition and data series becomes more closed; On the base of mapping data exchanging method using Schema conversion , heterogeneous PQ data exchange is successfully implemented. 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.