Abridgment of automatic control of Edison systems: As applied in the St. Charles street substation of the Union Electric Light and Power company

A brief description of the Edison System at St. Louis is given, and power supply, service restoration, and system balance are discussed. The relation of the St. Charles St. Substation to the remainder of the system is pointed out and certain features of its design explained. The scheme of loading the machines and the method of load shifting between machines is given in detail. The distinctive features of the various types of machines at this station are discussed, particular attention being given to the control of the converter with transformer taps and high-voltage revolving field booster. The scheme of automatically changing taps under load is described fully. A brief summary of the protective features on this machine is also given. The operating experience with the automatic equipment at the St. Charles St. Station is related.