Three-Phase Power Flies: Frankfurt Electrifies the World
The International Electrotechnical Exhibition in Frankfurt demonstrated the first practical long-distance transmission of three-phase alternating current on May 16, 1891, sending 175 horsepower of electricity 175 kilometers from a hydroelectric plant at Lauffen am Neckar. The system, designed by Mikhail Dolivo-Dobrovolsky, achieved 75% efficiency, far exceeding what direct current systems could manage over such distances. This demonstration settled the "War of Currents" between Thomas Edison's DC system and George Westinghouse's AC system decisively in favor of alternating current. Three-phase power became the global standard for electrical grids because it delivers constant power, enables efficient use of copper conductors, and is naturally suited to rotating electric motors. Every power grid in the world today uses this technology.
May 16, 1891
135 years ago
Key Figures & Places
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