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Distribution Management System
Jesus Polite Arbea
Cláudia de Oliveira e Silva Varricchio
José Maria Carvalho Azevedo
Jesus Polite Arbea
Cláudia de Oliveira e Silva Varricchio
José Maria Carvalho Azevedo
Abstract
This paper presents the main aspects of CERJ´s Distribution Management System- SGD, which is formed by products from GE\Smallworld Systems Inc, including Smallworld 3.1, PowerOn, Smallworld Web and from Power Technologies Inc. – PTI, PSS/Engines and PSS/ADEPT. The main functions of modules Electric Network and Cartographic Information, Electric System Analyses and Outage Management are described.
Introduction
The Cia de Eletricidade do Rio de Janeiro - CERJ is an Electric Utility having a service area of about 35.000 km² in 66 cities in Rio de Janeiro – Brazil. The company provides electricity services to about 1.800.000 customers. In the new competitive environment of the electric sector, the utilities are constantly searching means to guarantee service quality and employee productivity in increasing levels. For these reasons in 1998 CERJ launched SGD project in order to improve its distribution management.
Distribution management encompasses all aspects of planning, constructing, maintaining and operating the distribution system to meet the needs of customers in the utility’s service area trying to improve constantly customer satisfaction. The fundamental activity (major challenge) of the utility is to always provide power to its customers when they need it and at the lowest price. Utilities are taking advantage of developments in GIS software to re-engineer business processes
The main SGD development goals were:
- Integration of the major distribution engineering functions in an unique management system
- Creation of an unique electric system database
The CERJ´s SGD is composed of functions commonly used in electric system distribution. Its implementation was done in a platform that provides traditional AM/FM/GIS functions and capabilities, supporting business applications that requires geospatial data, and that allows an integration with other CERJ´s information systems such as Customer Information System and SCADA. SGD´s database was built in two stages:
a) Cartographic Database
Cadastral maps creation, including orthophoto and digitized cartographic data, by aerial photogrammetry of all CERJ´s service area. The restitution scale used, shown below, varied according to whether the area being covered was classified as being urban, semiurban or rural.
Rural – 1: 10.000 in 33.000 km²
Semi-urban – 1:5.000 in 374 km²
Urban – 1:2.000 in 1.975 km²
b) Electric Network Database A complete and unique database was built from the data field capture of all electric devices (feeders, switchers, transformers, etc) and customers. After this task has been concluded these information were converted to a specific computational format. The data quality control was done by randomically sampling some data and comparing it with its corresponding data field.
Techinical Aspects
Hardware and Software Architecture
The CERJ´s district offices and headquarters are linked via wide area networks and local area networks to ensure smooth data sharing capabilities. There are about 80 workstations running via a corporate network.
Fig 1 - Hardware Architecture
CERJ´S SGD uses Smallworld´s Version Management tools to coordinate updates to database by multiple users in each district. Activities such as design and planning that depend on it often require several different scenarios to be handled at the same time. A specific application groups together the changes an individual user makes to the database during a given activity, however long it takes. No other user is affected by these changes until the activity is completed and they are automatically reconciled to the authoritative master database. The result is that each user has access to its own private version, without risk of data integrity. Two users can work safely with the same area of the database.
Data Maintenance
Once data capture has been finished the greater challenge is the database maintenance. CERJ has developed a Data Maintenance Plan basically composed by:
- Definition of procedures to guarantee the database update
- Periodic audits in the district offices to verify the procedures accomplishment
- Implementation of data quality indices
CERJ´s SGD provides a customized database maintenance environment for users throughout the organization while maintaining information in a common database accessible to all employees through location queries. This environment provides functions, via an user-friendly and point-and-click interface, to edit and query objects for both cartographic and electric network information.
Object Editors
Through tools editor, called Object Editor, users are able to edit both the geometry and text attributes of an object. Figures 2 and 3 show examples of TRANSFORMERS and STREETS editions.
Fig 2 - Transformer Editor
Fig 3 – Street Editor
Object’s properties, such as symbology, drawing priority, visibility and selectability are defined by a dialog box, called Object Control, that shows an index of the contents of the database as shown in figure 4.
Fig 4 - Object Controller
Query Bowser
Through a Query Browser, that allows a combination of spatial and alphanumeric queries, users are able to build interactive queries by typing requests to database in a user-friendly environment.
Fig 5 – Query Browser
Orthophoto
One of the sub-products of cartographic information is orthophoto that helps users to have a detailed vision of the area that surrounds an electric network as shown in figure 6.
Fig 6 – Orthophoto
Quality Control
There are some Quality Control tools available in SGD used to detect errors in electric network information. The most important are:
- Network tracing and connectivity analyze
- Loops detection
- Multi or not energized objects detection
The main functions of Project Management available in SGD are:
- Project tracking
- Project design
SGD uses programs from PTI - PSS-ADEPT (Power System Simulator / Advanced Distribution Engineering Productivity Tool) and PSS/Engines (SmallWorld-PTI Interface), integrated to SmallWorld GIS, for planning, designing and analyzing distribution systems.
Analyses functions provided are:
- Power flow and losses
- Short circuit calculations Protection and co-ordination
- Capacitor placement optimization
Calculations are processed in a high speed way and results are displayed to users both in screen and reports. It’s possible to configure the application to display nodes out-ofrange conditions. Figure 7 shows an example of SmallWorld-PTI Interface after power flow calculations.
Fig 7 – Power Flow Results
Outage Distribution Mmanagement System
Trouble Call Rreporting
CERJ has developed a Trouble Call Management System (EGAT) that allows Call Center to report service problems quickly, This system has an interface with customer information system and another one with the Outage Management System (PowerOn). Basically EGAT provides:
- Automatic identification of the customer by his name, address, customer number or telephone number
- Automatic transfer of interruptions information to PowerOn
- Customer feedback for known outages such as estimated restoration time
Fig 8 – EGAT Main Screen
Service Rerstoration and Outage Management
Smallworld PowerOn is an outage management system that automates service restoration process. It has been customized to attend CERJ’s functional requirements. PowerOn is completely integrated with CERJ´s Distribution Management System - SGD, which provides some benefits:
- Common database (avoid redundant data)
- Common data model and symbology
- Access to common functionality in both environment
- Common user interface
Prediction/Identification of Failed Equipment
PowerOn automates the call analysis process by utilizing customer information system and electric network information to group related customers calls and predict the probable device. Configurable prediction rules eliminate the manual and time-consuming processes required to determine the electrical devices that have failed, significantly reducing customer interruption time.
Dispatching Functions
Once outage tickets are generated, dispatching tools are provided to quickly dispatch the appropriate crews. Work lists are prioritized to highlight both emergency work and outages affecting large numbers of customers.
Figure 9 shows both the Control Window, which provides dispatching tools, and the Map Window where the probable affected area is yellow highlighted helping dispatch center to deal with the outage.
Fig 9 – Control and Map Window
Schematic Diagram Generation
This functionality provided by PowerOn 2.0 is been customized for CERJ´s needs and will generate all schematic information, including primary devices (conductors, switches, reclosers, sectionalizers and circuit breakers). Editing tools will be available if specific changes are needed to the schematic diagram.
Planned Switching
This functionality provided by PowerOn 2.0 is been customized for CERJ´s needs and will allow the creation and editing of planned switching requests, their associated orders and clearances. This functionality will provide a “Simulation Mode” that will allow the operator to see firsthand the effects of a particular switching operations before assigning it.
SCADA Interface
It has been implemented PowerOn/SCADA Interface to CERJ´s SCADA that will include both digital events such as switch operations and analog events such as amperage and voltage samplings by phase.
Generation of Supply Quality Indices
PowerOn was customized to provide the main supply quality indices requested by Brazil’s Regulatory Agency – ANEEL.
Conclusions
Implementation of SGD gave CERJ a fast and effective way of meeting customers’ expectations. It has been noticed an improvement in services and a significant reduction in customer interruption time caused by the greater accessibility to information and the use of powerful tools for electric network analyses.
Another benefit of SGD’s implementation is the distribution management centralization that allows the reduction of the number of dispatcher centers as consequence of the use of a complete, unique and centralized database. After SGD’s implementation, CERJ created a unique Call Center to register customers’ complaints and reduced the number of dispatcher centers from 16 to 3.