The application of active database based on Petri net detection technology in power monitor system

In monitor and control process of power system, the database are usually visited passively. However, the whole process requires many active visits that can not be met sufficiently by the single and passive visit of the traditional database. An active database consists of DBS, a traditional relational database, EB, a collection of active rules driven by events, and EM, a event monitor module to supervise whether the event in EB occurs. The event detection system in EM module has been analyzed; the problem is that, especially for complex events, results are different with different arithmetic. To better resolve the conflicts and to faster detect these complex events, this paper introduces a detection arithmetic based on Petri net with both synchronism and asynchronism features.