C I R E D Session Number 3 INTEROPERABILITY ISSUES IN MODELLING AND DEVELOPING SUBSTATION CONTROL SOFTWARE G. Dondossola*, F. Maestri*, J. Szanto* * CESI Italy dondossola@cesi.it The purpose of the paper is to present ideas on how to produce interoperable software for substation automation functions. The objective of the authors is to explore interoperability issues in ASME – Automation Software Modelling and Development Environment. ASME supports high level design of automation logic followed by conversion of the specified functions into executable code to be distributed on heterogeneous devices from different suppliers. Interoperability issues arise at different levels of the design and development process involved in the implementation of automation software modules: modelling and notation; information exchange format; compliance of the specified software interfaces with the emerging standard for communication in power systems. In ASME automata networks are modelled using state and network diagrams derived from an extension of the UML (Unified Modelling Language) notation, the object-oriented modelling standard released by the OMG in 1997. A UML- like Profile for ASME has been defined and a first prototype of the related user-interface has been implemented. Based on the ASME object meta-model, a data interface has been defined to consent diagrams to be converted into XML (eXtensible Markup Language) documentation. The XML representation of an ASME specification provides an easily understandable interface towards external tools and a ready to use intermediate language for the tools of the ASME environment. The automatic conversion of the user input into an XML specification file is one of the main functions of the UML based Graphical User Interface; preliminary steps towards the XML file generation have been implemented in the present GUI prototype. This paper is mainly focused on the integration of substation automation functions designed by ASME with the Substation Control architectures specified in accordance with IEC 61850, with particular reference to the Substation Configuration Language (SCL). A first aspect of ASME-SCL integration is related to hardware virtualisation. ASME functions access process data through a structured virtual image of the primary equipment originating/using the data. Each module of the hardware image is mapped into an IEC 61850-7-4 compliant logical node modelling the behaviour of the primary equipment. A second aspect of ASME-SCL integration consists in specifying the exhaustive hardware and software architecture of a substation by combined use of SCL and ASME. First we define substation topology and the related IED architecture in an SCL configuration file, then we map ASME defined automation logic to substation functions by means of IEC 61850 logical nodes. A natural mapping is established between SCL defined logical node interfaces and the data flow connecting the structured automation functions designed in the ASME environment. Both integration aspects have been exemplified on a sample application consisting of station- and bay- level automation sequences, specified using the ASME environment. Following the extension rules expressed in 61850-7-4, standard logical nodes have been extended and new, compatible, logical nodes have been defined whenever requested by the complexity of the automation functions to be modelled. The paper presents excerpts of the SCL configuration file specifying the sample substation architecture and mapping ASME defined automation software modules to 61850 logical nodes, and sections of the hardware abstraction layer of the sample application’s process interface, defined with 61850 compliant naming convention. Further integration issues address: the pre-configuration of IED stereotypes performing predefined, standardised substation automation sequences; and the automatic definition of the hardware image based on the SCL capability description of an IED (Intelligent Electronic Device) provided by the vendors. Integration of the ASME and IEC 61850 specification models provides a uniform view of all relevant features of substation automation, with the logical decomposition of the switchyard functions offering an ideal starting point for the structured design of the related automation functions. The highlighted integration issues may be considered a first step towards the definition of standard interfaces for interoperable automation software to be performed on heterogeneous IEDs. PUBBLICATO A5017757 (PAD – 670672)PUBBLICATO A5052004 (PAD – 724725)