Solutions / Rail & metro
Traction and station distribution for rail and metro systems
Rail power systems combine a high-voltage traction network with dense auxiliary loads in stations, tunnels and depots. SAGE Power supplies 27.5 kV AC traction switchgear, MV/LV station distribution and dry-type transformers built for the vibration, humidity and restricted access of transit environments.
27.5 kV
AC traction
1.5 / 3 kV
DC auxiliary
10–20 kV
station MV
Seismic
qualified structures
Design priorities
Where transit projects usually go wrong
01
27.5 kV AC traction switchgear
KYN61-40.5 withdrawable equipment with high short-circuit withstand, positive interlocking and compartmental segregation.
02
DC auxiliary distribution
1.5 kV / 3 kV DC switchgear and LV distribution for signalling, ventilation, lighting and depot loads.
03
Station and tunnel footprint
Compact RMUs and modular LV cabinets sized for electrical rooms with restricted access and strict fire-load limits.
04
Reliability under vibration
Seismic-rated structures, torque-checked busbars and anti-loosening hardware for continuous traffic loading.
Typical configuration
What a typical scheme looks like
Representative ratings for traction and auxiliary distribution; final values follow the traction power study.
- Traction: 27.5 kV AC, 1250–2000 A, 25/31.5 kA
- Auxiliary MV: 10 kV or 20 kV, ring or radial
- Transformer: SCB dry-type, 10 kV/0.4 kV, 500–2500 kVA
- LV: 400 V drawout or fixed, signalling and depot boards
- DC auxiliary: 1.5 kV / 3 kV switchgear on request
- Protection: numerical relays, interlocking, SCADA interface
Recommended equipment
Equipment we would put in this scheme
KYN61-40.5 switchgear
40.5 kV withdrawable metal-clad switchgear for traction and primary distribution with positive interlocking.
KYN28-12 switchgear
12 kV metal-clad withdrawable switchgear for station auxiliary and depot distribution.
SRM6-12 ring main unit
SF6-insulated RMU for compact station and tunnel distribution points with C, F and V modules.
SCB dry-type transformer
Cast-resin transformer for indoor station loads, 10 kV class, low partial discharge and no insulating oil.
How we deliver
One team from drawing review to commissioning
01
Engineering review
We start from your single-line diagram, load list and fault level, then confirm the topology, ratings and protection scheme before anything is quoted.
02
Manufacture and test
Switchgear, transformers and substations are built in Yueqing, routine tested and documented against the relevant IEC and GB standards.
03
Delivery and support
Export packing, drawings, test reports and O&M manuals travel with the shipment, with commissioning support available on site.
Questions buyers ask
Frequently asked questions
Are the switchgear structures seismic qualified?
Structures can be supplied with seismic calculation and anchor details for the project’s acceleration class; tell us the requirement at enquiry stage.
Do you supply 27.5 kV traction switchgear?
Yes. KYN61-40.5 withdrawable equipment is configured for 27.5 kV traction duty with the current and short-circuit ratings of your traction power study.
How do you handle restricted tunnel space?
Compact RMUs and modular LV cabinets reduce the footprint, with front-access designs and cable entry arranged to suit the tunnel or station room.
Can maintenance be done without long outages?
Withdrawable breaker compartments and interchangeable modules allow replacement of a truck or module while the busbar remains in service.
Equipping a traction substation or station?
Send the traction power study, station layout and DC auxiliary requirements. We will confirm the switchgear, transformer and LV scope.