Rehabilitation of the 230 kV substation for an aluminum smelter

Two of the twelve 100 MVA rectifier transformers at an aluminum smelter were defective. After an in-depth analysis and investigation, the remaining service life of these transformers was virtually nil. Given the scale of the issue and the significant financial losses that would be caused by a plant shutdown, the client had little time to locate the source of the failure and find a solution.

Our experts' solutions

The client turned to our BBA experts, who designed and implemented a rehabilitation plan for the 230 kV substation, including the electrical equipment for 12 rectifier sets, in an extremely tight timeframe. BBA experts established needs, analyzed data, drafted technical specifications, designed new facilities, performed factory acceptance tests, provided technical support, commissioned and, finally, tested performance. Indeed, BBA experts completed all mandate stages without having to shut down production.
- Post-mortem of two transformer-rectifiers and two regulating transformers
- Main equipment replacement: 12 transformer-rectifiers of over 110 MVA and 12, 116 MVA regulating transformers
- Factory acceptance tests and commissioning
- Auxiliary equipment replacement or upgrade: circuit breakers, metering units and 230 kV surge arresters, RC circuits, power rectifiers, 600 V distribution, protection and control circuits, communication network
- Air heater replacement for the existing regulating transformers
- Capacity increase for the oil recovery system and addition of an oil-water separator
- Addition of a backup 52 kV overhead line
- Addition of air conditioning in the technical corridors of each potline
- Addition of a backup cooling system in the rectifier rooms
- Strengthening of reactive power compensation, including harmonic filtering

Thanks to BBA’s expertise and vast experience as well as power systems and equipment, the client avoided a catastrophe that could have had significant consequences.

Yves Bétournay, Client Account Manager

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