This part of the IEC 61850 series introduces the modelling methods, communication principles, and information models that are used in the various parts of the IEC 61850-7-x series. The purpose of this part of the IEC 61850 series is to provide – from a conceptual point of view – assistance to understand the basic modelling concepts and description methods for: – substation-specific information models for power utility automation systems, – device functions used for power utility automation purposes, and – communication systems to provide interoperability within power utility facilities. Furthermore, this part of the IEC 61850 series provides explanations and provides detailed requirements relating to the relation between IEC 61850-7-4, IEC 61850-7-3, IEC 61850-7-2 and IEC 61850-5. This part explains how the abstract services and models of the IEC 61850-7-x series are mapped to concrete communication protocols as defined in IEC 61850-8-1. The concepts and models provided in this part of the IEC 61850 series may also be applied to describe information models and functions for: – hydroelectric power plants, – substation to substation information exchange, – information exchange for distributed automation, – substation to control centre information exchange, – information exchange for metering, – condition monitoring and diagnosis, and – information exchange with engineering systems for device configuration. NOTE 1 – This part of IEC 61850 uses examples and excerpts from other parts of the IEC 61850 series. These excerpts are used to explain concepts and methods. These examples and excerpts are informative in this part of IEC 61850. NOTE 2 – Examples in this part use names of classes (e.g. XCBR for a class of a logical node) defined in IEC 61850-7-4, IEC 61850-7-3, and service names defined in IEC 61850-7-2. The normative names are defined in IEC 61850-7-4, IEC 61850-7-3, and IEC 61850-7-2 only. NOTE 3 – This part of IEC 61850 does not provide a comprehensive tutorial. It is recommended that this part be read first – in conjunction with IEC 61850-7-4, IEC 61850-7-3, and IEC 61850-7-2. In addition, it is recommended that IEC 61850-1 and IEC 61850-5 also be read. NOTE 4 – This part of IEC 61850 does not discuss implementation issues.