Comparison of AC Motors to an Ideal Machine Part I—Conventional AC Machines

While comparison of the torque produced by the ac machines of a given topology is, today, a standard feature of the machine design process, comparison of machines from different families of machine types is less frequently undertaken. This two-part article compares the torque performance of 12 types of ac machines based on the same current density level, flux density level, and rotor dimensions. A new “tau” factor is introduced as means for a comparison of any ac machine with an “ideal” machine based upon Essen's equation.