UK Power Networks Services Powerlink Ltd - What We Do

UK Power Networks Services Powerlink Ltd is responsible for managing, operating, and maintaining the electrical power network for London Underground. 

London Underground’s power distribution system is connected to the National Grid at 5 main 132,000 volt bulk supply points, plus two other supply points at 66,000 volts and 33,000 volts.  A network of 22,000 volt and 11,000 volt feeder cables distribute power to over 220 substations, where the power is transformed down to provide 630 volt DC power to operate the trains, and 400 volt supplies to stations and other essential services. 

This can be summarised as follows:

• Distribution of electrical power to 142 London Underground stations and to all 400 km of track
• Provision of high-frequency power to the signalling systems via approximately 200 motor / generator frequency changers
• Provision of compressed air to operate the track points and other equipment via over 100 compressors
• Provision of Emergency power to station lighting and safety critical systems through over 250 on-line battery inverter systems
• Operation and maintenance of Greenwich Power Station for the provision of back-up emergency power in the event of a major failure of the National Grid
• Operation and maintenance of all HV plant and equipment including those installed by PADCo
• Full asset management of the London Underground HV power system
• Convert AC power to DC for the traction supplies