Auxiliary-power supply for generating stations

Industry, in general, has been adopting the electric motor drive and its control to all types of machines. In the central station, where sequential and correlated operation is a necessity, the use of electric-motor-driven auxiliaries also has shown a marked increase. All recent stations have been built with a major portion of their auxiliaries driven by electric motors. The author suggests the use of the station generator bus as the most reliable source of auxiliary-power supply in electric stations of a closely interconnected system similar to that in the Chicago area. Separate auxiliary service units, not exceeding in size the requirements of the largest turbogenerator unit, also are recommended.