THE CLIENT
A large multinational group operating in the energy and industrial sectors.
THE NEED
Obtain precise test voltages on motors with different specifications to ensure safety, stability and maximum system reliability.
The main technical requirements were:
- Rated power: 800 kVA
- Input voltage: 400 V (1155 A)
- Multi-tap outputs: 440 V, 480 V, 600 V, 690 V
- Permitted inrush current: up to 3 times nominal (3·In)
OUR SOLUTION
The design of a multi-tap autotransformer for motor test benches involves specific challenges that require advanced electromagnetic expertise.
Ortea designed and manufactured an 800 kVA multi-tap autotransformer for a motor test bench coupled with a 60 Hz frequency converter, developing the solution through a complete engineering process compliant with IEC 60076-11:2019 standards for dry-type transformers.
The construction included specific design measures:
- Optimized core geometries to reduce leakage fluxes
- Oversized cross-section windings to limit impedance
- Low-resistance conductor bars to minimize losses
- Cooling systems sized for prolonged test cycles
The custom design for multi-tap autotransformers resulted in a unit with excellent performance:
- Efficiency higher than 99% at full load
- Inrush current limited within 3·In
- Total losses lower than 2% of rated power
- Compliance with climatic classes E2 C2 F1 according to IEC 60076-11