Development And Application Of OPC Technology And DRTDB In SCADA System

SCADA (Supervisory Control and Data Acquisition) system is based on the computer process control and dispatching automation system. The system can run to the scene of the equipment monitor and control, in order to realize data acquisition, equipment control, measure and parameters adjustment and all kinds of signal alarm and other functions. SCADA system is the most widely used in power system. It involves the configuration software and data transmission link, etc. How to realize the local data sharing and data sharing between systems becomes an important research part of the system.OPC (Object Linking and Embedding for Process Control) technology is a set of interface technology, properties and method standards set based on Microsoft COM (Component Object Model) and DCOM (Distributed Component Object Model). Traditional drivers are provided by the compiled software developers. There are versions of multiple drivers in the SCADA system as different protocol used in the hardware vendor is different. This leads to huge redundancy system drivers, and increases the development cycle. This paper introduces OPC technology in the SCADA system is to provide a unified, open, efficient data communication mechanism, to realize the SCADA system internal data interaction, provides a bridge between hardware manufacturers and software developers.At present, the advanced SCADA system always has a real-time database system as a whole core of data processing, data organization and management. The traditional database system mainly emphasises on maintaining data integrity and consistency, improving the system throughput and reducing the system cost, without considering the timing associated with data and its processing limits, thus the traditional business model and management transactional DBMS (Database Management System) can’t meet the needs of real-time application. In this paper, the distributed real-time database is based on fastdb memory database. It has realized the real-time database basic functions, and at the same time combines OPC interface technology to realize the distributed architecture of database.This paper firstly introduces the research background and significance, analyzes the characteristics of the substation SCADA system, points out the advantages of using OPC technology and distributed real-time database according to the demand of the substation SCADA system. And then briefly introduces the OPC technology and distributed real-time database technology, and next deeply discusses the key technologies of OPC, OPC DA specification as well as the emphasis and difficulty of distributed real-time database technology, and then introduces the development process of the OPC DA server and distributed real-time database in detail. Finally, shows a multi-motor synchronization application based on OPC and DRTDB technology and its superiority in the substation SCADA system.In this paper the application of OPC technology is embodied in two, one is used between hardware devices and the host computer to complete data interaction and unify the data communication process; another is between different host computers to realize data synchronization and makes the SCADA system more complete and reliable. OPC technology mainly uses VC to develop COM module, COM/DCOM interface technology, Tear-off interface programming techniques, callback interface and connection point techniques. Using VC’s ATL(Active Template Library) to establish project, and using COM technology to develop DBMS.A multimachine test is taken and the results show that the scheme in this paper is accurate, real-time and consistent. And it can achieve data sharing in and between systems. So the system has a good utility value. Finally, it gives the summary and prospects.