CIM模型与关系模型的一种映射方法的探讨

以兰州电网智能决策支持系统为背景,以实现电力软件系统的互操作为目的,分析了公共信息模型(CIM)模型和电力系统的特征,提出了基于IEC61970标准的CIM模型与关系型数据库之间的一种映射方法,解决了面向对象模型与关系型模型灵活对应的问题:CIM模型的丰富完善并不会影响映射过程和映射效果。该映射方法尽可能地采用设立外键的方法,在不影响数据库性能的情况下建立必要的关系表,确保映射的关系型数据库能够完全表达CIM模型的各种关系;其中表名对应类名,域名对应本身属性,外键、专门的关系表、表中的属性对应泛化、聚合、简单关联关系。采用RationalRose和UML来描述映射的过程。该方法使得软件系统的数据库表完全遵循IEC61970标准,具有良好的兼容性;只要外部系统的接口能够遵循IEC61970标准,就可以同软件系统进行交互。

Discussion of a Way of Mapping CIM to Relative Model

This paper presents a method of mapping CIM of IEC61970 to relational databases based on the analysis of characteristics of CIM and power systems for the purpose of realizing interaction among different software systems in power systems.The Lanzhou Network Intelligent decision-making support system is used as a reference.This method provides an approach to flexibly mapping between an object-oriented model and a relational model.Under a condition that there should no any impact on performance of database systems, this method creates foreign keys as many as possible and establishes necessary relational tables in order to ensure CIM to be mapped to relational databases fully.In the mapping scheme,table name matches class name, domain name matches native attributes, and foreign key, special relation table and attributes in table match generalization, aggregation and simple association, respectively. The process of mapping is expressed by Rational Rose and UML. By using this method, database tables of a software system can comply with IEC61970 fully and these tables are also compatible. Moreover the system and other software systems whose interfaces accord with IEC61970 can visit each other.