High-Speed Rail

How stations and lineside facilities draw power

Power in high-speed rail stations, depots and lineside facilities goes to ventilation, lighting, lifts and escalators, HVAC and information systems, and most of these circuits must stay supplied throughout operating hours. Substations are usually placed on a basement level, in a plant mezzanine or in an ancillary chamber — enclosed spaces with long escape routes.

The first constraint in such places is fire. If equipment catches fire, the smoke and toxic gas in an enclosed space do far more harm than the loss of the equipment itself, which is why stations and underground facilities use dry-type transformers and set requirements for the flame retardance and self-extinguishing behaviour of the insulation.

What rail projects have to cope with

The difficulty in rail distribution is not the rating but where the equipment goes, and what happens if something fails.

• Substations underground or in enclosed spaces, with limited fire protection and smoke extraction
• Passenger flow producing marked day/night and holiday variation, with long light-load periods
• Noise-sensitive station buildings, with equipment close to public areas
• Tight plant rooms and narrow routes for installation and replacement
• Long operating hours, leaving only the night window for maintenance

Equipment therefore has to be flame-retardant and non-toxic in its materials, and as low as possible in loss and noise, before it belongs alongside passengers.

Coreda's approach for rail projects

For station buildings and their ancillary facilities we supply amorphous-alloy dry-type transformers with modular LV assemblies, balancing fire protection, efficiency and ease of installation and maintenance.

Recommended configuration:

• SCBH17 amorphous-alloy dry-type transformer: meets grade 2 energy efficiency for dry-type transformers, with no-load loss 15% lower, load loss 10% lower and no-load current about 20% lower than the previous SCBH15 generation; the fully sealed class H structure is flame-retardant and explosion-proof.
• SCBH15 and SGBH15 amorphous-alloy dry-type transformers: core wound from amorphous-alloy strip, no-load loss 75% below a conventional dry-type unit; windings impregnated several times with class H solvent-free varnish under vacuum pressure (VPI), releasing no harmful gas if they burn.
• MNS withdrawable LV switchgear: E = 25 mm basic module, up to 36 quarter-module drawers per cubicle, degree of protection selectable from IP30 to IP54, with extensive use of V0 flame-retardant engineering plastics.

Drawer units are mechanically and electrically interchangeable, so a faulty circuit can be restored with a spare unit inside the night window without affecting the next day's service.