Torque components due to space harmonics in induction motors

THE graphical method or circle diagram is undoubtedly the one most frequently employed in deriving speed-torque curves of induction motors from the design constants of the motor or from running and locked tests readings. In numerous papers and text books on induction motors are described quite a variety of circle diagrams, which have been developed for this purpose, each introducing more or less refined methods into the process. Steinmetz´ symbolic method lends itself readily to an analysis of the induction motor phenomena and formulas have been derived by him by means of which the complete performance can be calculated.