Search

The conventional power system domain includes various utility business processes that are carried out by multiple market participants. In the conventional setup, these processes are typically captured through various local representations understandable by the concerned actors in their respective subdomains. The heterogeneity in process representations can result in problems of traceability, transparency, time-trackability, and interoperability across actors and software systems. To orchestrate the utility business processes, the IEC has recently started an activity entitled “IEC 62325-451-2:2014” for representing the “energy scheduling business process” of the European market in a standardized way. Along similar lines, this paper presents a process ontology along with a systematic methodology for building process models of end-to-end process operations of power utility. The process ontology consists of power system process modeling artifacts such as process, participant, activity, gateway, event, and event-based subprocess. For representing events and chronology of task execution, the common information model (CIM) can be adopted, which is expected to act complementary to process ontology semantics. An energy scheduling application is considered as a case study, wherein the proposed process ontology artifacts and the CIM ontology are used for building process models for an “energy scheduling business process” in the Indian power grid context. [ABSTRACT FROM PUBLISHER]

Common Information Model (CIM) is widely adopted by many utilities since it offers interoperability through standard information models. Storing, processing, retrieving, and providing concurrent access of the large power network models to the various power system applications in CIM framework are the current challenges faced by utility operators. As the power network models resemble largely connected-data sets, the design of CIM oriented database has to support high-speed data retrieval of the connected-data and efficient storage for processing. The graph database is gaining wide acceptance for storing and processing of largely connected-data for various applications. This paper presents a design of CIM oriented graph database (CIMGDB) for storing and processing the largely connected-data of power system applications. Three significant advantages of the CIMGDB are efficient data retrieval and storage, agility to adapt dynamic changes in CIM profile, and greater flexibility of modeling CIM unified modeling language (UML) in GDB. The CIMGDB does not need a predefined database schema. Therefore, the CIM semantics needs to be added to the artifacts of GDB for every instance of CIM objects storage. A CIM based object-graph mapping methodology is proposed to automate the process. An integration of CIMGDB and power system applications is discussed by an implementation architecture. The data-intensive network topology processing (NTP) is implemented, and demonstrated for six IEEE test networks and one practical 400 kV Maharashtra network. Results such as computation time of executing network topology processing evaluate the performance of the CIMGDB. [ABSTRACT FROM AUTHOR]

Common information model (CIM) in vogue represents transmission and distribution components, and market operations in the perspective of electrical system, as unified modeling language (UML) objects. UML is object centric. CIM can offer interoperability and facilitate model exchange for large systems and is being adopted by many utilities. However, dealing effectively with multiple business processes is the backbone of the restructured power systems. Since CIM lacks chronological process sense, this has to be superimposed on CIM models, which is not easy due to inherent limitations of UML. To overcome this, this paper proposes to utilize business process modeling notation (BPMN) standards as a kind of pre-processor. BPMN is used to represent process centric interoperability requirements as business objects. UML object representation in CIM model is derived subsequently from it. The proposal is illustrated with an application use case—deriving CIM model of day-ahead market (DAM) transaction of distribution company, from its business process representation. Semantic model of DAM transaction using CIM IEC 62325 (Markets) and extensions required are presented with a sample Indian system. DAM models in BPMN and CIM can be utilized to build an efficient software application. [ABSTRACT FROM PUBLISHER]

In terms of scope and granularity of data, two kinds of connectivity models are broadly in vogue for representing power network data, namely, node-breaker model and bus-branch model. This paper examines both the connectivity models from the perspective of common information model (CIM). Although CIM is primarily designed for most detailed node-breaker representation, with certain extensions CIM can be leveraged to achieve a standard, interoperable bus-branch model representation and exchange format. To facilitate this, it is proposed to introduce new class called TopologyBranch. By decoupling the connectivity information and the equipment parameter information, a mechanism for efficient exchange of time varying system models with minimum information transfer between the power control centers is described in this paper. The proposed CIM bus-branch connectivity model has wide applications in an interoperable, decentralized, hierarchical structure of control centers. Three illustrative examples including one on a practical 20-substation model of the 400 kV transmission network of Maharasthra state, India, are then presented for demonstrating the benefits. [ABSTRACT FROM PUBLISHER]