Ontological Formulation of Microgrid Control System for Interoperability

IEC 61850 and Common Information Model (CIM) (IEC 61968/61970) are predominantly used in smart grid domain to achieve the interoperability. CIM focuses on the organizational structures of different components within the smart grid while IEC 61850 focuses on the structure of information exchanges between field devices and systems. CIM can possibly be used for power system domain ontology and indeed for physical modeling too. On the other hand, the IEC 61850-7-420 defines object classes for assets such as Distributed Energy Resource (DER) which may include solar generation, storage, diesel generators etc., DER unit controllers, and other DER-associated power electronic devices (e.g., inverter). These object classes describe asset-specific attributes such as type of assets, set points, state of charge, limits, and ramp rate etc. While acknowledging the cumbersomeness involved in IEC 61850 engineering, there is a need to develop an easily engineer-able and interoperable system that would achieve the efficient operation of microgrid control system. In this paper, we have modelled a subset of microgrid system using different semantic models and tried to formulate the ontology to achieve an intended interoperable information model. The proposed model generation and deployment would achieve easy integration and autonomous operation of devices from different vendors with different information models.