are made in sizes ranging from subfractional self-excited units to large-horsepower, direct-current-excited ac
motors for industrial drives. In the fractional-horsepower range, synchronous
motors are used primarily where precise constant speed is required. In large horsepower sizes applied to industrial loads, synchronous
motors serve two important functions. First, ac
motors provide highly
efficient means of converting ac
energy to mechanical power. Second, ac
motors can operate at leading...
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