CEMIG (Companhia Energética de Minas Gerais) is one of Brazil’s largest electric utilities, operating an extensive transmission network exceeding 140,000 km. CEMIG plays a crucial role in supplying electricity to the densely populated and industrialized regions of Minas Gerais and neighboring states.
ISA (Interconexión Eléctrica S.A.) is a leading Colombian power transmission company managing over 22,000 km of transmission lines and fostering regional grid interconnections across Colombia and neighboring countries.
Project Background and Challenges
Both utilities undertook major projects to upgrade aging transmission infrastructure to meet growing electricity demand and improve grid reliability. The projects required conductors with high ampacity, good corrosion resistance in tropical climates, and compatibility with existing tower structures to minimize retrofit costs.
CEMIG focused on reinforcing 230 kV and 345 kV corridors in Minas Gerais, while ISA aimed at expanding cross-border transmission capacity between Colombia and Ecuador at 230 kV and 500 kV levels.
Uni-Cable Products Supplied:
| Product Type | Specifications | Standards |
|---|---|---|
| ACSR (Aluminum Conductor Steel Reinforced) | 336.4 mm² aluminum with galvanized steel core, tensile strength 50 kN | IEC 61089, ASTM B232, ASTM B498 |
| AAAC (All Aluminum Alloy Conductor) | 397 mm² aluminum alloy wires, tensile strength 70 kN | IEC 61089, ASTM B398 |
AAAC link: https://cable-uni.com/products/bare-conductor/aaac-all-aluminum-alloy-conductor.html
ACSR link: https://cable-uni.com/products/bare-conductor/acsr-aluminum-conductor-steel-reinforced-cables.html
Project Scope:
Brazil CEMIG: 200 circuit km of ACSR 336.4 mm² conductors on 230 kV lines, reinforcing power flow in Minas Gerais
Colombia ISA: 150 circuit km of AAAC 397 mm² conductors on 230 kV and 500 kV cross-border lines for enhanced interconnection
Technical and Application Highlights:
ACSR selected for its high tensile strength and mechanical reliability on longer spans
AAAC chosen for its superior corrosion resistance and lighter weight, minimizing tower loading
Both conductor types designed to maintain low sag and stable performance at temperatures up to 75°C continuous
Compliance with tropical environment corrosion standards to ensure longevity in humid, coastal zones
Compatible fittings and accessories supplied, including tension clamps, suspension clamps, armor rods, vibration dampers, and corona rings, all tested per IEC 61284 and IEEE standards
Quality Assurance and Testing:
All conductors produced under ISO 9001 certified quality management systems
Routine tensile strength and elongation tests conducted on each production batch
Electrical resistance and sag performance validated at accredited laboratories
Accessories tested for mechanical load and electrical insulation properties
Packaging designed to prevent corrosion and mechanical damage during long-distance sea and land transport
Export Packaging and Logistics:
Conductors supplied on heavy-duty steel drums with protective anti-corrosion wrapping
Accessories packaged in custom crates with shock-absorbing materials
Coordinated shipping schedules ensured delivery aligned with project construction timelines
Experienced logistics handling for customs clearance and inland transport in Brazil and Colombia
Competitive factory-direct pricing with full traceability and batch certification
Proven conductor and accessory quality tailored for South American transmission conditions
Ability to supply large volumes with reliable lead times to meet urgent project schedules
Comprehensive technical support including stringing design and installation recommendations
Established export experience ensuring smooth customs and logistics processes in Latin America
Uni-Cable’s conductors and accessories enabled CEMIG and ISA to reinforce their key transmission corridors efficiently and cost-effectively, improving grid capacity and reliability while reducing downtime and maintenance costs. These projects have strengthened regional power networks and supported sustainable economic growth in South America.
