Dimensional modeling and data processing in data warehouse for regional power dispatch
Haitong Gu · Dianli zidonghua shebei · 2006
Based on the analysis,the data of operational systems for electric power dispatch are divided into three types:equipment description,periodical sample and events.More than 90 percent of warehouse data belong to the latter two types,most of them are real data.The method of sharing dimensional modeling is proposed.The source of data warehouse is the regional dispatch data relating to analysis.After data is processed in ETL(Extract,Transform,cleansing,Load) stage,they are saved into data warehouse,in the formation of data subset or data cube according to certain theme.There are 3NF(third Normal Form) scheme and star scheme for data warehouse dimensional modeling.The 3NF scheme is suitable for the core of data warehouse,while the star scheme is for data market to make query easier.The real data table and dimension table of dimensional model are described,and tables of sensor point dimension,date dimension and time dimension are designed.The data in ETL stage is the corresponding data of operational environments.After logical data model is transformed into physical data model,data is described in XML(eXtensible Markup Language) for data sharing between isomerous systems.It is pointed out that relations between fault and weather(temperature,humidity,etc.) or load should be considered.The basic dataflow of data mining by artificial neural networks is given.