Gemini project - Integrated solution for operation centers
Marcos V. Abi-Ackel, Cláudio L. Bonfim, Elaine F. Fonseca
Euler H. Teixeira, Leandro R. Medeiros
Cemig - Companhia Energética de Minas Gerais - Brazil
Av. Barbacena, 1200
30.190-131 - Belo Horizonte - MG - Brazil
Introduction
Cemig is the main power company in the state of Minas Gerais - Brazil and its purpose is the generation,
transmission and distribution of power within its concession area. Its main focus is electric power with a
basically-hydraulic generation matrix.
The company has about 4.9 million customers, distributed in an area of 586,000 km2 - about the same size as
France - 286,000 km of distribution network, and 365,000 transformers installed. About 10,000 km of
distribution networks are built every year to supply new customers, growing at an average annual rate of 7% .
Our customers are spread in agglomerations ranging from a big one, with 1.6 million customers - the
metropolitan region of Belo Horizonte, to a medium one - seven cities over 150,000 customers, and many
small centers about and over 3,000 customers, performing a total of 793 cities.
To manage this asset, the company has been investing, since the 1970's, in computer systems. The first
successful one was a mainframe-based system to control the low-tension secondary network, from the
transformer to the customer. This system has been very necessary because of the secondary network topology
used, which sometimes encloses many street blocks and hundreds of customers. The system was dubbed
CONSEC, which stands for Secondary Control, and was put into operation in 1982, using since the beginning
the UTM (Universal Transverse of Mercator) geographic coordinate system.
The evolution of the geographically-oriented systems was shortly like this:
Consec - (mainframe - IMS-based) secondary network control: from the distribution transformer to the
customer. Started its development in 1977, and was initially put into operation in 1981.
Conprim - (mainframe - IMS-based) primary network control: for the primary, 25 kV class feeders.
Started its development in 1981, and was initially put into operation in 1984.
Consec - (micro computer version - DOS) graphical user interface, showing the secondary data in
geographical form: Started its development in 1988, and was initially put into operation in 1990. This system
improved greatly the secondary data quality because of the graphical user interface and the very easy way to
check and modify the electrical network data.
Conprim - (micro computer version - DOS) interface based on primary schematic diagrams. Although the
interface was not geographic, the internal data was all UTM-based.
All these systems were completely developed inside the company by a specialized team consisting of
electrical engineers with a large experience in computer science.
From 1994 to February, 2000 the entire company used the microcomputer version of the CONSEC and
CONPRIM systems to manage its electrical network. The Gemini Project is now replacing these systems.
The Gemini Project was started in 1995 with the main purpose of evolving the existing network management
systems into a modern, completely integrated and GIS-based system. In December, 1998, the system was put
into operation in the main Operation Center of the company, in Belo Horizonte, eliminating the 2.5x13.5m
operation wall diagram and assisting all the operation tasks to the 1.5 million customers of the covered region.
Now (March, 2000) the Gemini project is in operation in all Operation Centers in the company, directly
assisting the operation tasks to the whole covered area, about 4.9 million customers. The old CONSEC and
CONPRIM systems are now being systematically replaced by the new system.
