Transmission and Distribution

PROJECT DESCRIPTION

GE Canada was awarded by Hydro-Québec a contract for the provision, installation and commissioning of the very first 100 MVA variable frequency transformer (VFT), located at the Langlois substation in St-Timothée, Quebec.  Subsequently, GE mandated BBA to carry out all engineering activities regarding VFT buildings, including the ventilation system regulating the enclosure's temperature

The mandate first consisted of developing the basic concepts for the call for tenders, including design engineering, plan and elevation views, the project cost estimate, and the planning of the work.

The second part of the mandate consisted of implementing the VFT, including the following activities: 

• Coordination and communication between the various participants, notably the GE and Hydro-Québec teams
• Mechanical engineering of building ancillary services, such as CVAC and fire detection/protection systems
• Electrical engineering of building ancillary services, such as high voltage distribution and the supply transfer system
• Engineering, supply and installation of the acoustic enclosure
• Engineering, supply and installation of the VFT ventilation system, including the control system
• Design using 3D software
• Preparing drawings according to Hydro-Québec standards and specifications
• Technical assistance to integrate the improvements desired by the client, such as:
  • Hot air exhaust
  • Carbon dust recovery
  • Compressed air supply to the enclosure
  • Emergency electrical supply system for the motorized ventilation louvers
  • Design and provision of a test unit for electrical isolation voltage (Hi Pot)

• Testing and commissioning the equipment

The VFT is a new technology developed by GE to interconnect two asynchronous networks. The Langlois substation is a world first.

The ventilation system must be capable of operating at outdoor temperatures ranging from -40°C to ჴ°C, while taking into account the heat generated by the VFT, i.e., 1 MW, and the specific requirements for air circulation within the VFT.

The area's design and layout and the detection of obstruction zones between systems have been carried out by BBA using detailed 3D modelling of the VFT.

The design of the systems as a whole makes it possible to disassemble and reassemble the enclosure and its numerous components in order to remove the VFT using a bridge crane.