Gateway to the future-control of power supplies to the London Underground

The author briefly discusses the development of power supply control for the London Underground. The introduction of computer technology in the 1970s and its subsequent upgrades has lead to the control being carried out from one control room. In the latest system an active controllable mimic diagram with front-end drivers for each substation is provided on a one-to-one basis. This gives basic control of the whole system and in the event of a fault, normally, control of only one substation is lost. Above this is a dual hot-standby computer system giving access to full control facilities and also to all the background information, such as minor indications and analogue facilities. Higher level functions such as energy management and a connection to an IPSA (Interactive Power System Analysis) load flow analysis facility, are also provided. Because of the importance of this control facility to the safety of our passengers, this configuration was selected to avoid the reliance of the whole system on single items of equipment such as the computers. Future expansion and upgrading of the Underground will need an updated control system. A solution to meeting the requirements is discussed