Experience in the application of substation co-ordinated control and protection with development trends in the standard control system open architecture

The transition from conventional secondary installations for substations to modern digital control and protection systems poses a different view on issues like investment and long term operational cost versus functional flexibility. Control, data acquisition and supervision of the substation is the first objective of the secondary installation. A new possibility introduced with digital control systems is the use of information management. Therefore the need of an open system architecture in substations and standard protocols for communication with other control systems becomes more important. In the substation the secondary installations consist of different digital or conventional subsystems like control, protection and metering. The integration of the subsystems is an important issue in a co-ordinated control and protection system. Experiences teach the importance of a clear understanding of the necessary information exchange between the subsystems to fully benefit the integration of these systems. Development trends towards open system interfaces within the SAS2000 system are discussed. Furthermore the use of digital control systems provides the opportunity to decrease the amount of cabling required in the substation by use of remote outdoor I/O modules directly mounted on the primary equipment. Condition controlled maintenance can be performed by periodic remote inspection of primary and secondary equipment properties, leading to a significant reduction in maintenance