Interoperable CORBA middleware design for substation communication systems

For the last few years, the standardization of communication and application protocols has lead to the evolution of power system control technology. The introduction of IEC 61850 and the utility communications architecture (UCA) has made it possible and justifiable to integrate station intelligent electronic devices (IEDs) through standardization. The use of existing standards and commonly accepted communication principles together with the new standards like the IEC 61850 and UCA provides a solid base for interoperability between IEDs in the substation leading to more flexible and powerful protection and control systems. However, more advances are needed in order to establish an open and standard working environment allowing for more and more functions to be developed. Forthcoming ideas need to follow the path opened by the IEC 61850 in order to provide advanced complements to the basic architecture. One of today´s most popular initiated and standard-working environments is common object request broker architecture (CORBA) middleware with set of services, which also allows for heterogeneous implementation of distribution applications. The main emphasis in this paper is to show the use of CORBA middleware communications for power system communications. The paper explains how the standard CORBA middleware can be extended to form an effective platform for real-time power system operations. The paper also deals with implementing the IEC 61850 protocol over the newly designed CORBA application thus showing how the interoperability requirements can be met while providing an effective platform for performance sensitive substation automation applications.