Yemula Pradeep

CIM-Based Connectivity Model for Bus-Branch Topology Extraction and Exchange

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.

CIM and IEC 61850 integration issues: Application to power systems

Common Information Model (CIM) is emerging as a standard for information modelling for power control centers. While, IEC 61850 by International Electrotechnical Commission (IEC) is emerging as a standard for achieving interoperability and automation at the substation level. In future, once these two standards are well adopted, the issue of integration of these standards becomes imminent. Some efforts reported towards the integration of these standards have been surveyed. This paper describes a possible approach for the integration of IEC 61850 and CIM standards based on mapping between the representation of elements of these two standards. This enables seamless data transfer from one standard to the other. Mapping between the objects of IEC 61850 and CIM standards both in the static and dynamic models is discussed. A CIM based topology processing application is used to demonstrate the design of the data transfer between the standards. The scope and status of implementation of CIM in the Indian power sector is briefed.

SmartGrid initiatives and power market in India

SmartGrids were introduced to make the grid operation smarter and intelligent. SmartGrid operations, upon appropriate deployment can open up new avenues and opportunities with significant financial implications. SmartGrids can continue towards enhancement of power market. The current status of the power market as well as initiations of SmartGrids in India are studied to scrutinize the potential power market enhancement with the advent of SmartGrids. This paper presents various SmartGrid initiatives and implications in the context of power market evolution in India.

High Level Event Ontology for Multiarea Power System

Exchange of event information among multiple interconnected power system operators has become imperative for integrated and secure operation of the system. Considerable literature is reported on the standardization of power system data, while limited work has been done on the standardization of events. In this paper, we define a high level event ontology for power systems comprising seven concepts, namely, event, event extractor, event consumer, time, measurement, location, and level. These concepts are then developed with details extracted from the operating procedures followed by national and regional load dispatch centers in the Indian national grid. The methodology adopted for designing concrete sub-ontologies from the high level event ontology is also reported. The proposed event ontology has wide applications in the areas of i) event driven architecture (EDA) which facilitates the integration of event driven applications within and across the utilities, and ii) complex event processing (CEP) which facilitates development of sense-and-respond software capable of processing events extracted from large volumes of real-time data streams.

CIM oriented database for topology processing and integration of power system applications

Although the standards-based systems integration of utility software applications using the domain data standard common information model (CIM) exists, many utilities are facing difficulties in managing of data exchanges among software application systems due to lack of standard oriented database management systems. The standard oriented database can be built from the CIM object oriented model using object-relational mapping (ORM). The generic design of ORM can handle object oriented model mapping to any database schema semantics. This paper presents a CIM oriented database (CIMODB) design through the object-relational mapping (ORM). The flexibility of data moving between object-oriented paradigms and relational database paradigms is achieved with the use of ORM concepts. Furthermore, the paper explores the integration of upstream power system applications with the proposed CIMODB, such as, topology processing, load-flow analysis, and more power system studies at the control center level from the legacy vendor software systems. A case study is illustrated to elaborate the CIMODB concept on the 400kV 20-substation Maharashtra network, which is the part of western region in India.

Towards usage of CIM in Indian Power Sector

India is moving on the path of rapid growth and restructuring with ever changing regulatory environment. There is a direct impact of this changing structure of power sector on system operation. New roles and responsibilities have to be taken up involving co-ordination with various external utilities. Standards based integration of systems and applications has become imperative. This paper provides an up-to-date report on the various initiatives and standardization activities in Indian Power Sector. The objective of the paper is to present the requirement and scope of standardization from the perspective of regional load despatch center (RLDC). Various applications used by RLDC and their data exchanges to perform its functions are described. A set of application usecases are then developed which document the data exchange requirements. Development of these usecases is the first step in adoption of common information model (CIM) and identification of necessary CIM extensions suitable for Indian scenario.

Graphics Model for Power Systems Using Layouts and Relative Coordinates in CIM Framework

Summary form only given. Conventional power system graphic applications use absolute coordinates approach, in which the objects are positioned with respect to a common origin. This can result in problems of re-adjustment and re-alignment in the network and substation diagrams when editing or merging the graphics. This paper introduces the notion of layouts and proposes a graphics model to facilitate positioning of graphical elements relative to each other in a hierarchy of layouts, there by, making the network diagrams flexible, sharable and extensible. This proposed graphics model, expressed in unified modeling language (UML) is shown to be compatible with the existing common information model (CIM) graphics model IEC 61970-453. Consequently, the need for extension of CIM graphics model is justified and an extension is proposed. Another key feature of the proposed model is configurability. Since, the necessary parameters are explicitly modeled, the user only needs to provide configuration information describing the hierarchical connectivity of the substation or the network. The absolute coordinates can be calculated from the configuration and the power system diagrams can be auto-generated. This paper demonstrates the above benefits highlighting the technologies for implementation. Case study on 400kV 20-substation diagrams of Maharashtra system in India is presented.

Complex event processing of high level events in multi-area power grid: An Indian perspective

Modern day power systems in the restructured environment have grown to a level of complexity that the use of automation has become imperative for secure operation and control. The volume of significant events that occur in a multi-area interconnected power system has become enormous to an extent that system operators need intelligent systems to support them in decision making. This paper presents an implementation of complex event processor (CEP) for processing high level power system events from the perspective of a multi-area system. The definition and modeling of basic and complex high level events is carried out and an event processing engine is employed to process data streams in real time to detect the occurrence of the events. Online real time data on the high voltage Indian national grid is used in this paper for driving the CEP system with the objective of detecting the occurrence of complex events. The methodology, implementation and results of the proposed CEP system are presented.

Representation of short-term open access transactions using common information model

Short term open access (STOA) transactions are one of the important mechanisms for exchange of power on Indian national grid. Currently, STOA is operated by five regional load despatch centers, leading to differences in representation of STOA transaction information. This paper presents the modeling of STOA using common information model (CIM). Use-case addressed includes, generation of a CIM/XML report which presents the STOA data for a given utility. The proposed system consists of five components namely, data acquisition, data conversion to CIM, data validation, STOA modeling in CIM and data visualization. The STOA transactions of the Western and Southern regions of India for the year 2011 have been used for building the database. The system is developed using python programming language, enterprise architect, and CIMTool for validation. The output generated creates a better understanding of market situation and thus is useful for the traders, generation utilities, discoms and system operators.