Erection, commissioning and start-up of two 400 kV to 115 kV, 300 MVA step-down power transformers · Acarigua Substation

• Scope of Service: Receipt of components, full assembly, high-vacuum oil treatment and FAT/SAT test protocols for two (2) new units.

1. Executive Summary

Key Impact: Increased transformation capacity and reliability of the National Electrical System in the plains region through the commissioning of 600 MVA of installed power. CAMEC successfully carried out the assembly of state-of-the-art technology from its arrival from the factory (China) through to final energization.

2. Technical Challenge (The Problem)

• Logistical Complexity: The Chint Electric units arrived in the country completely disassembled to allow transoceanic shipping. This called for technical inventory management and millimetre-precision assembly on site.
• Sensitivity of the Technology: As new 400/115 kV units, any assembly error or contamination during oil filling could have compromised the factory warranty and the stability of the 400 kV trunk network.
• Working Environment: Coordination of highly complex lifting operations to install large bushings and radiators under variable weather conditions in Portuguesa State.

3. Comprehensive Solution (Engineering by CAMEC)

CAMEC applied international erection protocols for extra-high-voltage equipment:

• Precision Mechanical Assembly: Installation of accessories, bushings, conservators and cooling systems under strict safety and cleanliness standards to prevent contamination of the new equipment's parts and components during assembly.
• Thermal Vacuum Treatment: Dielectric oil filling under deep high vacuum, ensuring the fluid met the standards for dielectric strength and absence of air bubbles (essential at 400 kV levels).
• Diagnostics and Functional Electrical Testing:
• Dielectric Analysis: Initial and final physical and chemical tests to validate oil quality.
• Turns Ratio (TTR) and Polarity: Verification of internal construction against the design.
• Insulation Resistance and Power Factor: To confirm that drying and filling were optimal.
• Winding Resistance: Validation of internal connections after transport.
• Bushings: The 400 kV bushings required separate capacitance and power factor testing.
• Protection System: Verification of the internal current transformers (CTs) and accessories (Buchholz relay, thermometers, level indicators, pressure relief valve, cooling system).

4. Results and Value Metrics

• 600 Additional MVA: The successful start-up of the two 300 MVA transformers strengthened the Acarigua transmission node, improving the voltage profile across the region.
• Erection Efficiency: A shipment of factory parts was turned into operating infrastructure in record time, demonstrating technical command of state-of-the-art Asian technology.

5. Technical Data · Asset Specifications