OPC Technology In Hydroelectric Power Station Supervisory System

OPC is an application of the technology of Object Linking and Embedding(OLE) which belongs to the Microsoft Corporation in the process control. The technology provides an uniform standard of developing the industrial automation software using the Object Oriented technology. The purpose of using the OPC technology is to offer a standard communication mechanism among the local devices and the lots of data source in the database of the industrial automation software.This paper discusses the communication mode between the local devices and the traditional surveillance and control software in the hydropower plant and its disadvantage in opening, re-usability and flexibility. After analyzing the characteristic and the application mode of the system integration in hydropower plant and the request in the future, discusses the meaning of using OPC in the communication aiming at the problem, which puzzling the most Integration merchant, of communicating between the surveillance and control system and the intelligent devices. This paper offers an application mode of OPC standard in the surveillance and control system of the hydropower plant in order to reduce the cost of the surveillance and control system and to protect the benefit of the user and the provider. In the end, an actual project is analyzed as an example.In the traditional hydropower plant communication system, the integration merchant must devote a great deal of energies to develop the communication software for each kind of intelligent devices that have the different communication protocol. The alteration to the devices will bring the software to a modify that can reduce the security of the system. Applying the OPC technology makes the system communication to be independent of the devices and simplifies the system structure. For the devices that want to be integrated in the system but can not offer the OPC interface, this paper presents two methods to complete such a function. One method is to use the communication software that running on the server end and communicating with the devices and offering the OPC service interface to implement the data issuance. The other method is to use the general communication platform, such as the communication management device. This device communicates with each kind of intelligent devices by the various field bus(232/485/422/CAN etc) and offers the OPC service interface and client interface. The topic finishes the dynamic link library for OPC interface and uses it in the OPC communication management software. In the end, an actual project in which the OPC technology used is analyzed as an example.