A Kind of Web-based Remote Supervisory and Control System for Power Plants in WAN

Main problems existing in remote supervision and control system (RSCS) in power plants today in China are that various software and hardware platforms exist in the integration of all parts of RSCS. Implementation of data exchange with these traditional methods is not general-purposed, information and data are difficult to transverse firewall installed by enterprises because of the private protocols used in distributed object technology. A RSCS in power plants based on Web Services are presented in this paper. Architecture, operational pattern and main features of Web Services are expounded. 2 kinds of nodes are included in RSCS in Power Plants Based on Web Services. Data acquisition based on OPC, data encapsulation based on Web Services, publication of Web Services, and design of supervisory and control service system (SCSS) orienting remote clients based on Web Services are included in design of gateway connecting local and remote nodes base on Web Services. Remote clients exchange data with SCSS by browsers. SCSS data exchange between SCSS and Web Services gateway is implemented with services description files and SOAP message. Developed and designed RSCS is applied in the remote supervision and control for water level in drum of boiler in a power plant. Project practice shows that designed RSCS in power plants based on Web Services is stable and reliable in operation with high integrability and openness and is worthy of application and popularization.