GIS integration with SCADA, DMS & AMR in Electrical Utility.Mr. Uday D. Kale Reliance Energy Ltd Santacruz ( EAST) Mumbai 400 055, India. uday.kale@rel.co.in Telephone number(s) : 0 932355 0631 Fax number : (022) 3009.9765 Mr. Rajesh Lad. Reliance Energy Ltd Santacruz ( EAST) Mumbai 400 055, India. rajesh.lad@rel.co.in Telephone number(s) : 0 932355 0631 Fax number : (022) 3009.9765 1.0 Abstract A typical Power System consists of Generation, Transmission & distribution. The basic structure of Power Transmission & Distribution system covers a huge network consisting of wide range of Equipments, Feeders & Facilities. To efficiently manage utility operations different disparate systems exist and the role of each system is different and unique. Typical systems used in the Electrical Utility are GIS, SCADA, DMS, NA & ERP. GIS (Geographical information system) is used to superimpose the complete electrical network assets from Generation to service point on top of the land base data. SCADA (Supervisory Control and Data Acquisition) system consist of complex network of electronic measuring & sensing instruments for capturing the data which is communicated over LAN, WAN to the control center. SCADA system like an alert watch dog monitors the utility network in real time and provides the remote control of switching devices, transformers and equipments. This facilitates Utility to coordinate the maintenance and fault rectification activities of the distribution system. DMS (Distribution Management System) supports operational improvements by using online network, and is used to efficiently manage the 11KV and below network by providing planned switching orders and load flow analysis to minimize losses and equipment overloads. In most cases the cost-benefit study reveals that commercially it is not viable to implement SCADA, DMS to every part of the distribution network. It is implemented to the key sections of distribution network. A more economical system called AMR too is used to fetch the Energy data from Station meters, feeder meters. AMR can augment the network data gaps from non SCADA/ DMS controlled stations. AMR which is mainly an energy data collector system, when integrated with GIS gives the required real time information of that part of the network which is not covered by SCADA/DMS. In such cases it can be used to support demand response, outage programs, engineering & planning initiatives and energy supply issues in conjunction with GIS. Integration of GIS with SCADA /DMS & AMR, leverages modern computing capabilities to deliver highly actionable information to a wide range of users, all while meeting the organization’s increasing need for real-time information. Advanced capabilities such as predictive analysis, simulation tools, contingency analysis and network monitoring can go far in giving utilities the power to be successful. This paper explains the need, approach & benefits of GIS integration with SCADA, DMS system in electric utility. 2.0 Need for SCADA,DMS&AMR integration with GIS: Indian Electrical utilities & various Business Systems In the present days, many of the Electrical utility companies in India are facing problems due to high energy losses, reduced quality & reliability of supply, billing issues, theft of energy, no proper strategic revenue collection methods, etc. This results in inefficient operation, consumer dissatisfaction & loss of market value of the utility in public. These problems are mainly associated with the Sub-transmission & distribution networks in the Power system. The present traditional approach to network development should be replaced by an approach based on technical and reliability requirements, economic considerations of costs of energy loss and expansion of system to meet the growth of prospective demand with least cost. Reliable and sufficiently detailed data of existing network is required to facilitate decision making in all activities of the Utility System Management. Improving efficiency and reducing down time and Controlling costs has become essential for a utility in order to be successful in the today’s highly competitive environment. With the huge & complex electrical distribution network consisting of many sources, feeders, alternate feeding points; updating and management of network data is a Herculean task. Current Electrical Utility business trend is characterized by, change in market conditions, regulatory requirements/policies which require utility to achieve greater competitiveness & effectiveness. Utilities are beginning to see a need for business systems to collect, store, and publish various types of data, sharing data among them & to maintain consistency of data. A key business trend is the implementation of information Technology. Number of disparate systems exists to achieve specific tasks. Most of the utility companies implement IT systems like SAP, ISU-CCS, SCADA, DMS, AMR, OMS and GIS for their business operations. Theses IT systems are proving flexible and adaptable enough to meet changing market conditions at various levels of the organization. These IT systems are working in isolation with each other. Data is maintained & accessible to only those who use these systems. Data existing in one system can be directly made available to other systems; by Integration of these systems. Data requirement for various users could be - Real time data from SCADA/DMS, energy consumption data from AMR, Consumer data from ISU-CCS, complete network data from GIS. As can be seen, the data requirement is very voluminous. This data has to be stored, retrieved and used by many different people at different locations for various purposes. If data has to be handled manually, then it is very likely that the data may get displaced or destroyed. No system can use as substitute for another system. Hence integration strategy/techniques are required to exchange data from different systems. Though SCADA, DMS are used in business operations on real time basis, GIS as asset management, the organization should think in the direction of using all theses systems as integrated one to manifold their advantages. 3.0 Why GIS as Base System for Integration Having seen the need for the integration it will be worthwhile to investigate which should be the base system. Right from the Generating point to the consumer, electrical network has a geographical reference. This can be created / mapped in GIS with geographical context in a unique way which may not be possible in any other business system. GIS enables fast, accurate & unique presentation of network data. GIS output of electric network can be viewed & easily interpreted compared to any other system output. Presenting and managing the entire assets of the utility in a pictorial manner is easily understandable by utility personnel. GIS technology promises benefits not only in increasing operational efficiency but also in improving policy design, decision making, communication, and dissemination of information. GIS can be used in Electrical Utility for management for:
GIS can help in day-to-day operation & maintenance as it provides the accurate, reliable spatial & non-spatial information to the utility operational staff. It can help engineer in finding most optimum route to take for inspections or maintenance jobs. GIS can now become an integral part of a utility’s mainstream daily operations. In addition to added functionality, integrated GIS may be easier and less costly to support. There is no such requirement of having proprietary hardware, software platform, and special skills for GIS implementation. By virtue of openness of GIS, interoperability is easily possible with other systems. A true enterprise GIS for utility company means access to GIS that deals with geographically dispersed assets or customers by every employee. Many utilities consider the GIS system as the “ultimate” source database, acting as a common repository for all enterprise applications. This is done by integrating GIS technology into the mainstream business operations of the company.  Once the Enterprise GIS is implemented; it would act as the base system for all the organizational assets, and would cater to the requirements of other departments. The GIS electrical data model is designed keeping this as an important requirement. Enterprise GIS uses a shared central geodatabase that allows integration and dynamic updating of multiple GIS data sources. This considerably reduces the time-consumed for data updation, increases the compatibility of data with other systems and also simplifies the translation issues. Since it is based around industry IT standards and web services the non-GIS applications and systems would be able to easily access GIS functionality, and GIS applications. Every system (for e.g. SCADA, Network Analysis, AMR etc) in a utility has a specialized role to play. The GIS system is never a substitute to any of these systems, but once integrated enterprise wide, it would enhance their capabilities, hence increasing the benefits. 4.0 What is SCADA, DMS & AMR? We would now like to explain in brief the SCADA, DMS & AMR systems? SCADA/DMS: SCADA (Supervisory Control & Data Acquisition System) is used to monitor and control the electrical utility network from master location mostly at substation level. DMS (Distribution Management System) like SCADA this is a real time basis system, used to monitor, control, and optimize the performance of the distribution system. This system is implemented for partial or complete distribution system. It intoduce a certain measure of automation in to the distribution system. SCADA/DMS gathers real time information, such as status of switching devices, information of fault occurred in an electrical distribution system. Then transfers information from home station to a control center & vice versa. Carry out necessary analysis and control & displaying the information. What is AMR? Automatic Meter Reading (AMR) helps the utility to access the latest and accurate information from the metering devices. It provides savings in time, manpower, and helps efficiency and energy management. AMR helps in following areas: Meter-reading, Field services improvements, Non-meter reading efficiency improvements; Outage investigation, Outage follow up, Outage notification, Load Forecasting, Power quality monitoring, Demand-Response & Demand monitoring, Reliability and Implementation of Availability Based Tariffs etc.  5.0 Integration Functional Requirements: Coming from the need to understanding of systems let’s now move to the specifics of the integration i.e. Functional Requirements. The SCADA, GIS user needs are translated in a FRD document which becomes the start point for the process of integration. Listed below are some of the FRs. 5.1 SCADA/DMS - GIS Functional Requirements:
 Network Representation in GIS Network Representation in SCADA 5.2 AMR - GIS Integration Functional Requirements:
After FRD one must look at the data needs from the systems to be integrated. Following are the details of the data which is needed to satisfy the functional requirements. A) GIS (Geographical Information System) Topological (Network) data: Geographical map consisting Generation, Transmission, Distribution System & Consumer area including spatial & attribute information of following:
Automated Meter Reading (AMR) system is a very cost-effective business system, capable of handling several thousand residential, commercial & industrial meters at various voltage levels. Apart from collection of periodical energy consumption data it also measures the instantaneous values of few electrical quantities. 7.0 Integration technology & System Configuration Once the FRD is frozen and the data requirements are clear, the integration technology has to be decided. The following paragraphs are devoted to describe the technology adopted at Reliance Energy. There are several integration techniques / strategies, which can be used for SCADA/DMS & GIS integration. The integration technology discussed in this section is one, which is based on the ABB’s SCADA/DMS (Network Manager) & ESRI’s GIS technology (ArcGIS 9.0) being implemented at Reliance Energy Ltd. (Mumbai & Delhi). The primary aim is to access the data from Network Manager’s real time database. An emerging technology is Message- Oriented Middleware (MOM) where communication is based on publish – subscribe paradigm. This method enables easy extensions of additional receivers (subscribers) of the data as the sender (Publisher) does not need to be configured. Network manager has adapters for major MOMs like TIBCO, IBM etc. CORBA & COM middleware is supported. Bridges to the corresponding COM based OPC standard also exists. Reliance Energy Ltd. adopted the COM based OPC interface. 7.1 Interface Architecture – Salient Features This is an OPC Interface. The OPC interface consists of two components – “DAIS server” which is installed on SCADA/DMS & a “DAS/OPC bridge” (i.e. an OPC server to the OPC client and a DAIS client to the DAIS server). To use the OPC server OPC client shall be installed in the client system. This Bridge is provided by SCADA vendor. The bridge & OPC client is installed in the GIS system.  Fig 8.1 SCADA/DMS & GIS integration System Configuration 7.2 OPC Interface: Main requirement from SCADA/DMS & GIS interface that it should support industry standards, data exchange & communication with enterprise GIS system requires high quality, high reliability & high performance interface. These interface requirements can be easily met by OPC. OPC stands for Object Linking and Embedding (OLE) for Process Control. OPC is a worldwide standard of application interface in industrial automation software and the enterprise systems that support industry. It is world wide proven & leading technology internationally, successfully tested & established for different process industries. OPC simplifies the interfacing between automation components (SCADA controlled devices) and GIS applications. The application of the OPC standard interface makes possible, interoperability between SCADA/DMS controlled devices/components and GIS applications. The adoption of OPC for integration enables easy & flexible access from GIS to real time data from SCADA/DMS system. The data is available in OPC Server as it acts as a data folder. OPC interface supported complies with OPC Data Access specification from OPC foundation (ref: OPC DA ver. 2.05) 7.3 DAIS (Data Acquisition from Industrial Systems):
Export of real time data from SCADA/DMS to GIS will be achieved by standard OPC (DIAS) subscription interface API. Data will be available on the DAIS interface to be subscribed-to in a user friendly manner (a browser interface). Subscriptions can be cyclic with specified cycle-times Data Subscription: DAIS supports both subscription and read/write operations. A subscription means that the server has no a prior knowledge of clients and it is clients that establish connection with servers. Once connection is established a server calls the client's callback when data becomes available or updated. The callbacks mean the DAIS API also defines an interface that the client has to implement.  Fig. 8.2 Data Subscription Above figure shows the bi-directional subscription with connection establishment and call-back interfaces. The DAIS API is intended for transfer of process data on subscription basis. Process data comes with quality tagged and time stamp. The API is intended to efficiently transfer large amounts of data simultaneously to client (subscriber). Any DAIS client can define a collection of data that is stored in the server as interesting and get the DAIS server to report it to the client. The reporting can be performed as a snapshot or as continuous reporting on change of data, i.e. subscription (the client defines how the data is reported when the group is created). A client may of course define several groups and the behavior of the data reporting is defined for each of these groups. A group created by a client is unique for the client. All item data (digital, analog signals etc.) in the Server are tagged with a unique identity could be a candidate for subscription. This data is available from RTUs / FEPs in the SCADA/DMS systems. Calculated data, parameters might also come from applications (e.g. custom calculations, state estimations, and optimization) in SCADA/DMS. These data can also be available through the DAIS Server API. 7.5 Prerequisite for OPC Interface:
To examine the performance requirements of an SCADA-GIS integrated system, it is useful to look at them in the context of system functions, the factors that affect performance requirements for each function, and the affected system components. 7.8 SCADA/DMS Data Transmission factors that affect system performance:
DAIS server maintain buffer for which data needs to be read by client. DAIS shall hold this information for a predefined time period during which the client has to read data group-wise from the buffer. 8.0 RISK Factor, Issues & Challenges The integration process is not so straight forward. There are many issues which need to be tackled at various levels. Detailed below are few technical issues. The data model of SCADA/DMS is designed keeping in mind the power system’s operation in real time basis. Every signal (alarm, status, analog value) is modeled as an object in SCADA/DMS. On other side in GIS data modeling is done keeping in mind the need of geographical representation of equipments, facilities etc., need of asset management etc. Hence the GIS object could be equipment, facility which, may or may not have geographical reference. Hence the mapping of signals from these real time systems to GIS is not a straight forward job. GIS data model is not a constraint rather it should be prepared carefully to fulfill the integration requirement of mapping strategy of objects & attributes. For identification of objects, SCADA/DMS follows the naming convention system which is generally based on the position of the object in Network configuration; however GIS follows the one which is normally based on its geographical position or any other criteria. Understanding different identity formats of same objects in both the systems need a proper mapping strategy, which is challenging task. Data Maintenance, a vital part of any distribution company operation, requires keeping the data models updated in both systems. With network expansion, maintenance and equipment upgrades, this becomes a challenging task. Incremental update in Electrical network should reflect in all these integrated systems simultaneously otherwise it will lead to discrepancy in network models of the integrated systems. 9.0 Benefits of Integration Discussed below are some of the benefits that can be seen by enterprise wide GIS integration with SCADA/DMS & AMR systems. This Integration requires considerable investment in hardware, software, development etc depending upon the business, its scope of integration & requirement.
Attempt has been made to show the readers how the Electric Utility that implement different IT systems to manage utility Business & operations find GIS integration with SCADA/DMS, AMR most useful for having real time data in relation with critical data. This interface helps to meet the requirement of utility managers, executives who are looking for new ways to - optimize their operations, increase workforce efficiency and the business processes. These capabilities distinguish GIS from other information systems and makes it valuable in explaining events, predicting outcomes and planning strategies for Distribution System Management. Integration of GIS with SCADA /DMS & AMR, leverages modern computing capabilities to deliver highly actionable information to a wide range of users, all while meeting the organization’s increasing need for real-time information. Advanced capabilities such as predictive analysis, simulation tools, contingency analysis and network monitoring can go far in giving utilities the power to be successful. Reliance Energy has opted to keep GIS as a base system & integrate it with SCADA/DMS & AMR using emerging integration technology. It can be said to be successful when it results in not only operational improvements but business improvement as well. |