A.C. Standby Power Systems for Satellite Communications Earth Stations

British Telecom´s advanced earth satellite communications systems are continuing to expand, and now form a significant feature of the UK´s capacity to handle International traffic. The power systems which back up the multiplicity of facilities at the two major earth stations at Goonhilly Downs in Cornwall, and Madley in Herefordshire, are essential to the provision of a highly reliable communications service. These power facilities are dependant on the ac standby plant which forms the heart of the reserve power capability of each site. This paper reviews the earlier types of standby engine generating plant, and goes on to describe in some detail the philosophy and design concept of the modern systems which are now in service. The two main stations in the UK both have standby plant comprising multiple engine sets with generators operating at 11,000 volts. The power complexes and the distributions systems are described, including the control and power protection arrangements. The paper concludes with a section which outlines the future trends for such plant, and mentions the third BT earth satellite station called London Teleport.